Bump version to 0.0.263 (#4086)

.gitignore

@@ -3,6 +3,7 @@
 crates/ruff/resources/test/cpython
 mkdocs.yml
 .overrides
+github_search.jsonl
 
 ###
 # Rust.gitignore

BREAKING_CHANGES.md

@@ -1,5 +1,40 @@
 # Breaking Changes
 
+## 0.0.260
+
+### Fixes are now represented as a list of edits ([#3709](https://github.com/charliermarsh/ruff/pull/3709))
+
+Previously, Ruff represented each fix as a single edit, which prohibited Ruff from automatically
+fixing violations that required multiple edits across a file. As such, Ruff now represents each
+fix as a list of edits.
+
+This primarily affects the JSON API. Ruff's JSON representation used to represent the `fix` field as
+a single edit, like so:
+
+```json
+{
+    "message": "Remove unused import: `sys`",
+    "content": "",
+    "location": {"row": 1, "column": 0},
+    "end_location": {"row": 2, "column": 0}
+}
+```
+
+The updated representation instead includes a list of edits:
+
+```json
+{
+    "message": "Remove unused import: `sys`",
+    "edits": [
+        {
+            "content": "",
+            "location": {"row": 1, "column": 0},
+            "end_location": {"row": 2, "column": 0},
+        }
+    ]
+}
+```
+
 ## 0.0.246
 
 ### `multiple-statements-on-one-line-def` (`E704`) was removed ([#2773](https://github.com/charliermarsh/ruff/pull/2773))

CONTRIBUTING.md

@@ -116,8 +116,7 @@ At a high level, the steps involved in adding a new lint rule are as follows:
 To define the violation, start by creating a dedicated file for your rule under the appropriate
 rule linter (e.g., `crates/ruff/src/rules/flake8_bugbear/rules/abstract_base_class.rs`). That file should
 contain a struct defined via `#[violation]`, along with a function that creates the violation
-based on any required inputs. (Many of the existing examples live in `crates/ruff/src/violations.rs`,
-but we're looking to place new rules in their own files.)
+based on any required inputs.
 
 To trigger the violation, you'll likely want to augment the logic in `crates/ruff/src/checkers/ast.rs`,
 which defines the Python AST visitor, responsible for iterating over the abstract syntax tree and
@@ -215,6 +214,20 @@ them to [PyPI](https://pypi.org/project/ruff/).
 Ruff follows the [semver](https://semver.org/) versioning standard. However, as pre-1.0 software,
 even patch releases may contain [non-backwards-compatible changes](https://semver.org/#spec-item-4).
 
+## Ecosystem CI
+
+GitHub Actions will run your changes against a number of real-world projects from GitHub and
+report on any diagnostic differences. You can also run those checks locally via:
+
+```shell
+python scripts/check_ecosystem.py path/to/your/ruff path/to/older/ruff
+```
+
+You can also run the Ecosystem CI check in a Docker container across a larger set of projects by
+downloading the [`known-github-tomls.json`](https://github.com/akx/ruff-usage-aggregate/blob/master/data/known-github-tomls.jsonl)
+as `github_search.jsonl` and following the instructions in [scripts/Dockerfile.ecosystem](scripts/Dockerfile.ecosystem).
+Note that this check will take a while to run.
+
 ## Benchmarks
 
 First, clone [CPython](https://github.com/python/cpython). It's a large and diverse Python codebase,

Cargo.toml

@@ -3,7 +3,7 @@ members = ["crates/*"]
 
 [workspace.package]
 edition = "2021"
-rust-version = "1.67"
+rust-version = "1.69"
 homepage = "https://beta.ruff.rs/docs/"
 documentation = "https://beta.ruff.rs/docs/"
 repository = "https://github.com/charliermarsh/ruff"
@@ -11,7 +11,7 @@ authors = ["Charlie Marsh <charlie.r.marsh@gmail.com>"]
 
 [workspace.dependencies]
 anyhow = { version = "1.0.69" }
-bitflags = { version = "1.3.2" }
+bitflags = { version = "2.1.0" }
 chrono = { version = "0.4.23", default-features = false, features = ["clock"] }
 clap = { version = "4.1.8", features = ["derive"] }
 colored = { version = "2.0.0" }
@@ -44,7 +44,7 @@ similar = { version = "2.2.1" }
 smallvec = { version = "1.10.0" }
 strum = { version = "0.24.1", features = ["strum_macros"] }
 strum_macros = { version = "0.24.3" }
-syn = { version = "1.0.109" }
+syn = { version = "2.0.15" }
 test-case = { version = "3.0.0" }
 textwrap = { version = "0.16.0" }
 toml = { version = "0.7.2" }

README.md

@@ -47,16 +47,16 @@ all while executing tens or hundreds of times faster than any individual tool.
 
 Ruff is extremely actively developed and used in major open-source projects like:
 
-- [pandas](https://github.com/pandas-dev/pandas)
-- [FastAPI](https://github.com/tiangolo/fastapi)
-- [Transformers (Hugging Face)](https://github.com/huggingface/transformers)
 - [Apache Airflow](https://github.com/apache/airflow)
+- [FastAPI](https://github.com/tiangolo/fastapi)
+- [Hugging Face](https://github.com/huggingface/transformers)
+- [Pandas](https://github.com/pandas-dev/pandas)
 - [SciPy](https://github.com/scipy/scipy)
 
 ...and many more.
 
-Read the [launch blog post](https://notes.crmarsh.com/python-tooling-could-be-much-much-faster) or
-the most recent [project update](https://notes.crmarsh.com/ruff-the-first-200-releases).
+Ruff is backed by [Astral](https://astral.sh). Read the [launch post](https://astral.sh/blog/announcing-astral-the-company-behind-ruff),
+or the original [project announcement](https://notes.crmarsh.com/python-tooling-could-be-much-much-faster).
 
 ## Testimonials
 
@@ -137,7 +137,7 @@ Ruff can also be used as a [pre-commit](https://pre-commit.com) hook:
 ```yaml
 - repo: https://github.com/charliermarsh/ruff-pre-commit
   # Ruff version.
-  rev: 'v0.0.261'
+  rev: 'v0.0.263'
   hooks:
     - id: ruff
 ```
@@ -332,55 +332,68 @@ Ruff is released under the MIT license.
 
 ## Who's Using Ruff?
 
-Ruff is used in a number of major open-source projects, including:
+Ruff is used by a number of major open-source projects and companies, including:
 
-- [pandas](https://github.com/pandas-dev/pandas)
-- [FastAPI](https://github.com/tiangolo/fastapi)
-- [Transformers (Hugging Face)](https://github.com/huggingface/transformers)
-- [Diffusers (Hugging Face)](https://github.com/huggingface/diffusers)
+- Amazon ([AWS SAM](https://github.com/aws/serverless-application-model))
 - [Apache Airflow](https://github.com/apache/airflow)
-- [SciPy](https://github.com/scipy/scipy)
-- [Zulip](https://github.com/zulip/zulip)
-- [Bokeh](https://github.com/bokeh/bokeh)
-- [Pydantic](https://github.com/pydantic/pydantic)
-- [PostHog](https://github.com/PostHog/posthog)
-- [Dagster](https://github.com/dagster-io/dagster)
-- [Dagger](https://github.com/dagger/dagger)
-- [Sphinx](https://github.com/sphinx-doc/sphinx)
-- [Hatch](https://github.com/pypa/hatch)
-- [PDM](https://github.com/pdm-project/pdm)
-- [Jupyter](https://github.com/jupyter-server/jupyter_server)
-- [Great Expectations](https://github.com/great-expectations/great_expectations)
-- [ONNX](https://github.com/onnx/onnx)
-- [Polars](https://github.com/pola-rs/polars)
-- [Ibis](https://github.com/ibis-project/ibis)
-- [Synapse (Matrix)](https://github.com/matrix-org/synapse)
-- [SnowCLI (Snowflake)](https://github.com/Snowflake-Labs/snowcli)
-- [Dispatch (Netflix)](https://github.com/Netflix/dispatch)
-- [Saleor](https://github.com/saleor/saleor)
-- [Pynecone](https://github.com/pynecone-io/pynecone)
-- [OpenBB](https://github.com/OpenBB-finance/OpenBBTerminal)
-- [Home Assistant](https://github.com/home-assistant/core)
-- [Pylint](https://github.com/PyCQA/pylint)
-- [Cryptography (PyCA)](https://github.com/pyca/cryptography)
-- [cibuildwheel (PyPA)](https://github.com/pypa/cibuildwheel)
-- [build (PyPA)](https://github.com/pypa/build)
+- AstraZeneca ([Magnus](https://github.com/AstraZeneca/magnus-core))
+- Benchling ([Refac](https://github.com/benchling/refac))
 - [Babel](https://github.com/python-babel/babel)
-- [featuretools](https://github.com/alteryx/featuretools)
-- [meson-python](https://github.com/mesonbuild/meson-python)
-- [ZenML](https://github.com/zenml-io/zenml)
-- [delta-rs](https://github.com/delta-io/delta-rs)
-- [Starlite](https://github.com/starlite-api/starlite)
-- [telemetry-airflow (Mozilla)](https://github.com/mozilla/telemetry-airflow)
-- [Stable Baselines3](https://github.com/DLR-RM/stable-baselines3)
-- [PaddlePaddle](https://github.com/PaddlePaddle/Paddle)
-- [nox](https://github.com/wntrblm/nox)
-- [Neon](https://github.com/neondatabase/neon)
-- [The Algorithms](https://github.com/TheAlgorithms/Python)
-- [Openverse](https://github.com/WordPress/openverse)
-- [MegaLinter](https://github.com/oxsecurity/megalinter)
+- [Bokeh](https://github.com/bokeh/bokeh)
+- [Cryptography (PyCA)](https://github.com/pyca/cryptography)
+- [Dagger](https://github.com/dagger/dagger)
+- [Dagster](https://github.com/dagster-io/dagster)
+- [DVC](https://github.com/iterative/dvc)
+- [FastAPI](https://github.com/tiangolo/fastapi)
+- [Gradio](https://github.com/gradio-app/gradio)
+- [Great Expectations](https://github.com/great-expectations/great_expectations)
+- Hugging Face ([Transformers](https://github.com/huggingface/transformers), [Datasets](https://github.com/huggingface/datasets), [Diffusers](https://github.com/huggingface/diffusers))
+- [Hatch](https://github.com/pypa/hatch)
+- [Home Assistant](https://github.com/home-assistant/core)
+- [Ibis](https://github.com/ibis-project/ibis)
+- [Jupyter](https://github.com/jupyter-server/jupyter_server)
 - [LangChain](https://github.com/hwchase17/langchain)
 - [LlamaIndex](https://github.com/jerryjliu/llama_index)
+- Matrix ([Synapse](https://github.com/matrix-org/synapse))
+- Meltano ([Meltano CLI](https://github.com/meltano/meltano), [Singer SDK](https://github.com/meltano/sdk))
+- Modern Treasury ([Python SDK](https://github.com/Modern-Treasury/modern-treasury-python-sdk))
+- Mozilla ([Firefox](https://github.com/mozilla/gecko-dev))
+- [MegaLinter](https://github.com/oxsecurity/megalinter)
+- Microsoft ([Semantic Kernel](https://github.com/microsoft/semantic-kernel), [ONNX Runtime](https://github.com/microsoft/onnxruntime))
+- Netflix ([Dispatch](https://github.com/Netflix/dispatch))
+- [Neon](https://github.com/neondatabase/neon)
+- [ONNX](https://github.com/onnx/onnx)
+- [OpenBB](https://github.com/OpenBB-finance/OpenBBTerminal)
+- [PDM](https://github.com/pdm-project/pdm)
+- [PaddlePaddle](https://github.com/PaddlePaddle/Paddle)
+- [Pandas](https://github.com/pandas-dev/pandas)
+- [Poetry](https://github.com/python-poetry/poetry)
+- [Polars](https://github.com/pola-rs/polars)
+- [PostHog](https://github.com/PostHog/posthog)
+- Prefect ([Python SDK](https://github.com/PrefectHQ/prefect), [Marvin](https://github.com/PrefectHQ/marvin))
+- [Pydantic](https://github.com/pydantic/pydantic)
+- [PyInstaller](https://github.com/pyinstaller/pyinstaller)
+- [Pylint](https://github.com/PyCQA/pylint)
+- [Pynecone](https://github.com/pynecone-io/pynecone)
+- [Robyn](https://github.com/sansyrox/robyn)
+- Scale AI ([Launch SDK](https://github.com/scaleapi/launch-python-client))
+- Snowflake ([SnowCLI](https://github.com/Snowflake-Labs/snowcli))
+- [Saleor](https://github.com/saleor/saleor)
+- [SciPy](https://github.com/scipy/scipy)
+- [Sphinx](https://github.com/sphinx-doc/sphinx)
+- [Stable Baselines3](https://github.com/DLR-RM/stable-baselines3)
+- [Starlite](https://github.com/starlite-api/starlite)
+- [The Algorithms](https://github.com/TheAlgorithms/Python)
+- [Vega-Altair](https://github.com/altair-viz/altair)
+- WordPress ([Openverse](https://github.com/WordPress/openverse))
+- [ZenML](https://github.com/zenml-io/zenml)
+- [Zulip](https://github.com/zulip/zulip)
+- [build (PyPA)](https://github.com/pypa/build)
+- [cibuildwheel (PyPA)](https://github.com/pypa/cibuildwheel)
+- [delta-rs](https://github.com/delta-io/delta-rs)
+- [featuretools](https://github.com/alteryx/featuretools)
+- [meson-python](https://github.com/mesonbuild/meson-python)
+- [nox](https://github.com/wntrblm/nox)
 
 ## License
 

_typos.toml

@@ -5,3 +5,4 @@ extend-exclude = ["snapshots", "black"]
 trivias = "trivias"
 hel = "hel"
 whos = "whos"
+spawnve = "spawnve"

crates/flake8_to_ruff/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "flake8-to-ruff"
-version = "0.0.261"
+version = "0.0.263"
 edition = { workspace = true }
 rust-version = { workspace = true }
 

crates/ruff/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "ruff"
-version = "0.0.261"
+version = "0.0.263"
 authors.workspace = true
 edition.workspace = true
 rust-version.workspace = true
@@ -21,13 +21,15 @@ ruff_python_ast = { path = "../ruff_python_ast" }
 ruff_python_semantic = { path = "../ruff_python_semantic" }
 ruff_python_stdlib = { path = "../ruff_python_stdlib" }
 ruff_rustpython = { path = "../ruff_rustpython" }
+ruff_text_size = { path = "../ruff_text_size" }
 
+annotate-snippets = { version = "0.9.1", features = ["color"] }
 anyhow = { workspace = true }
 bitflags = { workspace = true }
 chrono = { workspace = true }
 clap = { workspace = true, features = ["derive", "string"], optional = true }
 colored = { workspace = true }
-dirs = { version = "4.0.0" }
+dirs = { version = "5.0.0" }
 fern = { version = "0.6.1" }
 glob = { workspace = true }
 globset = { workspace = true }
@@ -48,6 +50,7 @@ path-absolutize = { workspace = true, features = [
 ] }
 pathdiff = { version = "0.2.1" }
 pep440_rs = { version = "0.3.1", features = ["serde"] }
+quick-junit = { version = "0.3.2" }
 regex = { workspace = true }
 result-like = { version = "0.4.6" }
 rustc-hash = { workspace = true }
@@ -57,6 +60,7 @@ schemars = { workspace = true }
 semver = { version = "1.0.16" }
 serde = { workspace = true }
 serde_json = { workspace = true }
+similar = { workspace = true, features = ["inline"] }
 shellexpand = { workspace = true }
 smallvec = { workspace = true }
 strum = { workspace = true }
@@ -68,9 +72,11 @@ typed-arena = { version = "2.0.2" }
 unicode-width = { version = "0.1.10" }
 
 [dev-dependencies]
-insta = { workspace = true, features = ["yaml", "redactions"] }
+insta = { workspace = true }
 pretty_assertions = "1.3.0"
 test-case = { workspace = true }
+# Disable colored output in tests
+colored = { workspace = true, features = ["no-color"] }
 
 [features]
 default = []

crates/ruff/resources/test/fixtures/eradicate/ERA001.py

@@ -9,6 +9,7 @@ def foo(x, y, z):
     print(x, y, z)
 
     # This is a real comment.
+    # # This is a (nested) comment.
     #return True
     return False
 

crates/ruff/resources/test/fixtures/flake8_bandit/S101.py

@@ -1,11 +1,13 @@
-# Error
-assert True
+assert True  # S101
+
 
 def fn():
     x = 1
+    assert x == 1  # S101
+    assert x == 2  # S101
 
-    # Error
-    assert x == 1
 
-    # Error
-    assert x == 2
+from typing import TYPE_CHECKING
+
+if TYPE_CHECKING:
+    assert True  # OK

crates/ruff/resources/test/fixtures/flake8_bandit/S602.py

@@ -0,0 +1,20 @@
+from subprocess import Popen, call, check_call, check_output, run
+
+# Check different Popen wrappers are checked.
+Popen("true", shell=True)
+call("true", shell=True)
+check_call("true", shell=True)
+check_output("true", shell=True)
+run("true", shell=True)
+
+# Check values that truthy values are treated as true.
+Popen("true", shell=1)
+Popen("true", shell=[1])
+Popen("true", shell={1: 1})
+Popen("true", shell=(1,))
+
+# Check command argument looks unsafe.
+var_string = "true"
+Popen(var_string, shell=True)
+Popen([var_string], shell=True)
+Popen([var_string, ""], shell=True)

crates/ruff/resources/test/fixtures/flake8_bandit/S603.py

@@ -0,0 +1,20 @@
+from subprocess import Popen, call, check_call, check_output, run
+
+# Different Popen wrappers are checked.
+Popen("true", shell=False)
+call("true", shell=False)
+check_call("true", shell=False)
+check_output("true", shell=False)
+run("true", shell=False)
+
+# Values that falsey values are treated as false.
+Popen("true", shell=0)
+Popen("true", shell=[])
+Popen("true", shell={})
+Popen("true", shell=None)
+
+# Unknown values are treated as falsey.
+Popen("true", shell=True if True else False)
+
+# No value is also caught.
+Popen("true")

crates/ruff/resources/test/fixtures/flake8_bandit/S604.py

@@ -0,0 +1,5 @@
+def foo(shell):
+    pass
+
+
+foo(shell=True)

crates/ruff/resources/test/fixtures/flake8_bandit/S605.py

@@ -0,0 +1,25 @@
+import os
+
+import commands
+import popen2
+
+# Check all shell functions.
+os.system("true")
+os.popen("true")
+os.popen2("true")
+os.popen3("true")
+os.popen4("true")
+popen2.popen2("true")
+popen2.popen3("true")
+popen2.popen4("true")
+popen2.Popen3("true")
+popen2.Popen4("true")
+commands.getoutput("true")
+commands.getstatusoutput("true")
+
+
+# Check command argument looks unsafe.
+var_string = "true"
+os.system(var_string)
+os.system([var_string])
+os.system([var_string, ""])

crates/ruff/resources/test/fixtures/flake8_bandit/S606.py

@@ -0,0 +1,20 @@
+import os
+
+# Check all shell functions.
+os.execl("true")
+os.execle("true")
+os.execlp("true")
+os.execlpe("true")
+os.execv("true")
+os.execve("true")
+os.execvp("true")
+os.execvpe("true")
+os.spawnl("true")
+os.spawnle("true")
+os.spawnlp("true")
+os.spawnlpe("true")
+os.spawnv("true")
+os.spawnve("true")
+os.spawnvp("true")
+os.spawnvpe("true")
+os.startfile("true")

crates/ruff/resources/test/fixtures/flake8_bandit/S607.py

@@ -0,0 +1,44 @@
+import os
+
+# Check all functions.
+subprocess.Popen("true")
+subprocess.call("true")
+subprocess.check_call("true")
+subprocess.check_output("true")
+subprocess.run("true")
+os.system("true")
+os.popen("true")
+os.popen2("true")
+os.popen3("true")
+os.popen4("true")
+popen2.popen2("true")
+popen2.popen3("true")
+popen2.popen4("true")
+popen2.Popen3("true")
+popen2.Popen4("true")
+commands.getoutput("true")
+commands.getstatusoutput("true")
+os.execl("true")
+os.execle("true")
+os.execlp("true")
+os.execlpe("true")
+os.execv("true")
+os.execve("true")
+os.execvp("true")
+os.execvpe("true")
+os.spawnl("true")
+os.spawnle("true")
+os.spawnlp("true")
+os.spawnlpe("true")
+os.spawnv("true")
+os.spawnve("true")
+os.spawnvp("true")
+os.spawnvpe("true")
+os.startfile("true")
+
+# Check it does not fail for full paths.
+os.system("/bin/ls")
+os.system("./bin/ls")
+os.system(["/bin/ls"])
+os.system(["/bin/ls", "/tmp"])
+os.system(r"C:\\bin\ls")

crates/ruff/resources/test/fixtures/flake8_bugbear/B017.py

@@ -1,9 +1,10 @@
 """
 Should emit:
-B017 - on lines 20
+B017 - on lines 23 and 41
 """
 import asyncio
 import unittest
+import pytest
 
 CONSTANT = True
 
@@ -34,3 +35,14 @@ class Foobar(unittest.TestCase):
     def raises_with_absolute_reference(self):
         with self.assertRaises(asyncio.CancelledError):
             Foo()
+
+
+def test_pytest_raises():
+    with pytest.raises(Exception):
+        raise ValueError("Hello")
+
+    with pytest.raises(Exception, "hello"):
+        raise ValueError("This is fine")
+
+    with pytest.raises(Exception, match="hello"):
+        raise ValueError("This is also fine")

crates/ruff/resources/test/fixtures/flake8_bugbear/B031.py

@@ -78,6 +78,21 @@ for _section, section_items in itertools.groupby(items, key=lambda p: p[1]):
     for shopper in shoppers:
         collect_shop_items(shopper, section_items)  # B031
 
+for _section, section_items in itertools.groupby(items, key=lambda p: p[1]):
+    _ = [collect_shop_items(shopper, section_items) for shopper in shoppers]  # B031
+
+for _section, section_items in itertools.groupby(items, key=lambda p: p[1]):
+    # The variable is overridden, skip checking.
+    _ = [_ for section_items in range(3)]
+    _ = [collect_shop_items(shopper, section_items) for shopper in shoppers]
+
+for _section, section_items in itertools.groupby(items, key=lambda p: p[1]):
+    _ = [item for item in section_items]
+
+for _section, section_items in itertools.groupby(items, key=lambda p: p[1]):
+    # The iterator is being used for the second time.
+    _ = [(item1, item2) for item1 in section_items for item2 in section_items]  # B031
+
 for _section, section_items in itertools.groupby(items, key=lambda p: p[1]):
     if _section == "greens":
         collect_shop_items(shopper, section_items)
@@ -134,6 +149,16 @@ for group in groupby(items, key=lambda p: p[1]):
     collect_shop_items("Joe", group[1])
 
 
+# https://github.com/charliermarsh/ruff/issues/4050
+for _section, section_items in itertools.groupby(items, key=lambda p: p[1]):
+    if _section == "greens":
+        for item in section_items:
+            collect_shop_items(shopper, item)
+    elif _section == "frozen items":
+        _ = [item for item in section_items]
+    else:
+        collect_shop_items(shopper, section_items)
+
 #  Make sure we ignore - but don't fail on more complicated invocations
 for _key, (_value1, _value2) in groupby(
     [("a", (1, 2)), ("b", (3, 4)), ("a", (5, 6))], key=lambda p: p[1]

crates/ruff/resources/test/fixtures/flake8_comprehensions/C414.py

@@ -7,11 +7,14 @@ set(set(x))
 set(list(x))
 set(tuple(x))
 set(sorted(x))
+set(sorted(x, key=lambda y: y))
 set(reversed(x))
 sorted(list(x))
 sorted(tuple(x))
 sorted(sorted(x))
+sorted(sorted(x, key=lambda y: y))
 sorted(reversed(x))
+sorted(list(x), key=lambda y: y)
 tuple(
     list(
         [x, 3, "hell"\

crates/ruff/resources/test/fixtures/flake8_comprehensions/C418.py

@@ -0,0 +1,10 @@
+dict({})
+dict({'a': 1})
+dict({'x': 1 for x in range(10)})
+dict(
+    {'x': 1 for x in range(10)}
+)
+
+dict({}, a=1)
+dict({x: 1 for x in range(1)}, a=1)
+

crates/ruff/resources/test/fixtures/flake8_comprehensions/C419.py

@@ -1,4 +1,3 @@
-# PIE802
 any([x.id for x in bar])
 all([x.id for x in bar])
 any(  # first comment
@@ -15,5 +14,6 @@ all(x.id for x in bar)
 any(x.id for x in bar)
 all((x.id for x in bar))
 
+
 async def f() -> bool:
     return all([await use_greeting(greeting) for greeting in await greetings()])

crates/ruff/resources/test/fixtures/flake8_import_conventions/custom_banned.py

@@ -0,0 +1,16 @@
+import typing as t  # banned
+import typing as ty  # banned
+
+import numpy as nmp  # banned
+import numpy as npy  # banned
+import tensorflow.keras.backend as K  # banned
+import torch.nn.functional as F  # banned
+from tensorflow.keras import backend as K  # banned
+from torch.nn import functional as F  # banned
+
+from typing import Any  # ok
+
+import numpy as np  # ok
+import tensorflow as tf  # ok
+import torch.nn as nn  # ok
+from tensorflow.keras import backend  # ok

crates/ruff/resources/test/fixtures/flake8_import_conventions/custom_banned_from.py

@@ -0,0 +1,10 @@
+from logging.config import BaseConfigurator  # banned
+from typing import Any, Dict  # banned
+from typing import *  # banned
+
+from pandas import DataFrame  # banned
+from pandas import *  # banned
+
+import logging.config  # ok
+import typing  # ok
+import pandas  # ok

crates/ruff/resources/test/fixtures/flake8_pyi/PYI001.py

@@ -11,3 +11,7 @@ _T = TypeVar("_T")  # OK
 _TTuple = TypeVarTuple("_TTuple")  # OK
 
 _P = ParamSpec("_P")  # OK
+
+
+def f():
+    T = TypeVar("T")  # OK

crates/ruff/resources/test/fixtures/flake8_pyi/PYI001.pyi

@@ -11,3 +11,6 @@ _T = TypeVar("_T")  # OK
 _TTuple = TypeVarTuple("_TTuple")  # OK
 
 _P = ParamSpec("_P")  # OK
+
+def f():
+    T = TypeVar("T")  # OK

crates/ruff/resources/test/fixtures/flake8_pyi/PYI015.py

@@ -46,3 +46,48 @@ field229: dict[int, int] = {1: 2, **{3: 4}}  # Y015 Only simple default values a
 field23 = "foo" + "bar"  # Y015 Only simple default values are allowed for assignments
 field24 = b"foo" + b"bar"  # Y015 Only simple default values are allowed for assignments
 field25 = 5 * 5  # Y015 Only simple default values are allowed for assignments
+
+# We shouldn't emit Y015 within functions
+def f():
+  field26: list[int] = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11]
+
+
+# We shouldn't emit Y015 for __slots__ or __match_args__
+class Class1:
+  __slots__ = (
+    '_one',
+    '_two',
+    '_three',
+    '_four',
+    '_five',
+    '_six',
+    '_seven',
+    '_eight',
+    '_nine',
+    '_ten',
+    '_eleven',
+  )
+
+  __match_args__ = (
+    'one',
+    'two',
+    'three',
+    'four',
+    'five',
+    'six',
+    'seven',
+    'eight',
+    'nine',
+    'ten',
+    'eleven',
+  )
+
+# We shouldn't emit Y015 for __all__
+__all__ = ["Class1"]
+
+# Ignore the following for PYI015
+field26 = typing.Sequence[int]
+field27 = list[str]
+field28 = builtins.str
+field29 = str
+field30 = str | bytes | None

crates/ruff/resources/test/fixtures/flake8_pyi/PYI015.pyi

@@ -53,3 +53,48 @@ field229: dict[int, int] = {1: 2, **{3: 4}}  # Y015 Only simple default values a
 field23 = "foo" + "bar"  # Y015 Only simple default values are allowed for assignments
 field24 = b"foo" + b"bar"  # Y015 Only simple default values are allowed for assignments
 field25 = 5 * 5  # Y015 Only simple default values are allowed for assignments
+
+# We shouldn't emit Y015 within functions
+def f():
+  field26: list[int] = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11]
+
+
+# We shouldn't emit Y015 for __slots__ or __match_args__
+class Class1:
+  __slots__ = (
+    '_one',
+    '_two',
+    '_three',
+    '_four',
+    '_five',
+    '_six',
+    '_seven',
+    '_eight',
+    '_nine',
+    '_ten',
+    '_eleven',
+  )
+
+  __match_args__ = (
+    'one',
+    'two',
+    'three',
+    'four',
+    'five',
+    'six',
+    'seven',
+    'eight',
+    'nine',
+    'ten',
+    'eleven',
+  )
+
+# We shouldn't emit Y015 for __all__
+__all__ = ["Class1"]
+
+# Ignore the following for PYI015
+field26 = typing.Sequence[int]
+field27 = list[str]
+field28 = builtins.str
+field29 = str
+field30 = str | bytes | None

crates/ruff/resources/test/fixtures/flake8_pyi/PYI016.py

@@ -0,0 +1,35 @@
+# Shouldn't affect non-union field types.
+field1: str
+
+# Should emit for duplicate field types.
+field2: str | str  # PYI016: Duplicate union member `str`
+
+
+# Should emit for union types in arguments.
+def func1(arg1: int | int):  # PYI016: Duplicate union member `int`
+    print(arg1)
+
+
+# Should emit for unions in return types.
+def func2() -> str | str:  # PYI016: Duplicate union member `str`
+    return "my string"
+
+
+# Should emit in longer unions, even if not directly adjacent.
+field3: str | str | int  # PYI016: Duplicate union member `str`
+field4: int | int | str  # PYI016: Duplicate union member `int`
+field5: str | int | str  # PYI016: Duplicate union member `str`
+field6: int | bool | str | int  # PYI016: Duplicate union member `int`
+
+# Shouldn't emit for non-type unions.
+field7 = str | str
+
+# Should emit for strangely-bracketed unions.
+field8: int | (str | int)  # PYI016: Duplicate union member `int`
+
+# Should handle user brackets when fixing.
+field9: int | (int | str)  # PYI016: Duplicate union member `int`
+field10: (str | int) | str  # PYI016: Duplicate union member `str`
+
+# Should emit for nested unions.
+field11: dict[int | int, str]

crates/ruff/resources/test/fixtures/flake8_pyi/PYI016.pyi

@@ -0,0 +1,32 @@
+# Shouldn't affect non-union field types.
+field1: str
+
+# Should emit for duplicate field types.
+field2: str | str  # PYI016: Duplicate union member `str`
+
+# Should emit for union types in arguments.
+def func1(arg1: int | int):  # PYI016: Duplicate union member `int`
+    print(arg1)
+
+# Should emit for unions in return types.
+def func2() -> str | str:  # PYI016: Duplicate union member `str`
+    return "my string"
+
+# Should emit in longer unions, even if not directly adjacent.
+field3: str | str | int  # PYI016: Duplicate union member `str`
+field4: int | int | str  # PYI016: Duplicate union member `int`
+field5: str | int | str  # PYI016: Duplicate union member `str`
+field6: int | bool | str | int  # PYI016: Duplicate union member `int`
+
+# Shouldn't emit for non-type unions.
+field7 = str | str
+
+# Should emit for strangely-bracketed unions.
+field8: int | (str | int)  # PYI016: Duplicate union member `int`
+
+# Should handle user brackets when fixing.
+field9: int | (int | str)  # PYI016: Duplicate union member `int`
+field10: (str | int) | str  # PYI016: Duplicate union member `str`
+
+# Should emit for nested unions.
+field11: dict[int | int, str]

crates/ruff/resources/test/fixtures/flake8_pytest_style/PT006.py

@@ -49,3 +49,18 @@ def test_list_expressions(param1, param2):
 @pytest.mark.parametrize([some_expr, "param2"], [1, 2, 3])
 def test_list_mixed_expr_literal(param1, param2):
     ...
+
+
+@pytest.mark.parametrize(("param1, " "param2, " "param3"), [(1, 2, 3), (4, 5, 6)])
+def test_implicit_str_concat_with_parens(param1, param2, param3):
+    ...
+
+
+@pytest.mark.parametrize("param1, " "param2, " "param3", [(1, 2, 3), (4, 5, 6)])
+def test_implicit_str_concat_no_parens(param1, param2, param3):
+    ...
+
+
+@pytest.mark.parametrize((("param1, " "param2, " "param3")), [(1, 2, 3), (4, 5, 6)])
+def test_implicit_str_concat_with_multi_parens(param1, param2, param3):
+    ...

crates/ruff/resources/test/fixtures/flake8_return/RET504.py

@@ -3,7 +3,7 @@
 ###
 def x():
     a = 1
-    return a  # error
+    return a  # RET504
 
 
 # Can be refactored false positives
@@ -211,10 +211,10 @@ def nonlocal_assignment():
 def decorator() -> Flask:
     app = Flask(__name__)
 
-    @app.route('/hello')
+    @app.route("/hello")
     def hello() -> str:
         """Hello endpoint."""
-        return 'Hello, World!'
+        return "Hello, World!"
 
     return app
 
@@ -222,12 +222,13 @@ def decorator() -> Flask:
 def default():
     y = 1
 
-    def f(x = y) -> X:
+    def f(x=y) -> X:
         return x
 
     return y
 
 
+# Multiple assignment
 def get_queryset(option_1, option_2):
     queryset: Any = None
     queryset = queryset.filter(a=1)
@@ -246,4 +247,28 @@ def get_queryset():
 
 def get_queryset():
     queryset = Model.filter(a=1)
-    return queryset  # error
+    return queryset  # RET504
+
+
+# Function arguments
+def str_to_bool(val):
+    if isinstance(val, bool):
+        return val
+    val = val.strip().lower()
+    if val in ("1", "true", "yes"):
+        return True
+
+    return False
+
+
+def str_to_bool(val):
+    if isinstance(val, bool):
+        return val
+    val = 1
+    return val  # RET504
+
+
+def str_to_bool(val):
+    if isinstance(val, bool):
+        return some_obj
+    return val

crates/ruff/resources/test/fixtures/flake8_simplify/SIM105.py

@@ -59,3 +59,15 @@ def bar():
         return foo()
     except ValueError:
         pass
+
+def with_ellipsis():
+    try:
+        foo()
+    except ValueError:
+        ...
+
+def with_ellipsis_and_return():
+    try:
+        return foo()
+    except ValueError:
+        ...

crates/ruff/resources/test/fixtures/flake8_simplify/SIM222.py

@@ -42,3 +42,113 @@ if False and f() and a and g() and b:  # OK
 
 if a and False and f() and b and g():  # OK
     pass
+
+
+a or "" or True  # SIM222
+
+a or "foo" or True or "bar"  # SIM222
+
+a or 0 or True  # SIM222
+
+a or 1 or True or 2  # SIM222
+
+a or 0.0 or True  # SIM222
+
+a or 0.1 or True or 0.2  # SIM222
+
+a or [] or True  # SIM222
+
+a or list([]) or True  # SIM222
+
+a or [1] or True or [2]  # SIM222
+
+a or list([1]) or True or list([2])  # SIM222
+
+a or {} or True  # SIM222
+
+a or dict() or True  # SIM222
+
+a or {1: 1} or True or {2: 2}  # SIM222
+
+a or dict({1: 1}) or True or dict({2: 2})  # SIM222
+
+a or set() or True  # SIM222
+
+a or set(set()) or True  # SIM222
+
+a or {1} or True or {2}  # SIM222
+
+a or set({1}) or True or set({2})  # SIM222
+
+a or () or True  # SIM222
+
+a or tuple(()) or True  # SIM222
+
+a or (1,) or True or (2,)  # SIM222
+
+a or tuple((1,)) or True or tuple((2,))  # SIM222
+
+a or frozenset() or True  # SIM222
+
+a or frozenset(frozenset()) or True  # SIM222
+
+a or frozenset({1}) or True or frozenset({2})  # SIM222
+
+a or frozenset(frozenset({1})) or True or frozenset(frozenset({2}))  # SIM222
+
+
+# Inside test `a` is simplified.
+
+bool(a or [1] or True or [2])  # SIM222
+
+assert a or [1] or True or [2]  # SIM222
+
+if (a or [1] or True or [2]) and (a or [1] or True or [2]):  # SIM222
+    pass
+
+0 if a or [1] or True or [2] else 1  # SIM222
+
+while a or [1] or True or [2]:  # SIM222
+    pass
+
+[
+    0
+    for a in range(10)
+    for b in range(10)
+    if a or [1] or True or [2]  # SIM222
+    if b or [1] or True or [2]  # SIM222
+]
+
+{
+    0
+    for a in range(10)
+    for b in range(10)
+    if a or [1] or True or [2]  # SIM222
+    if b or [1] or True or [2]  # SIM222
+}
+
+{
+    0: 0
+    for a in range(10)
+    for b in range(10)
+    if a or [1] or True or [2]  # SIM222
+    if b or [1] or True or [2]  # SIM222
+}
+
+(
+    0
+    for a in range(10)
+    for b in range(10)
+    if a or [1] or True or [2]  # SIM222
+    if b or [1] or True or [2]  # SIM222
+)
+
+# Outside test `a` is not simplified.
+
+a or [1] or True or [2]  # SIM222
+
+if (a or [1] or True or [2]) == (a or [1]):  # SIM222
+    pass
+
+if f(a or [1] or True or [2]):  # SIM222
+    pass

crates/ruff/resources/test/fixtures/flake8_simplify/SIM223.py

@@ -37,3 +37,113 @@ if True or f() or a or g() or b:  # OK
 
 if a or True or f() or b or g():  # OK
     pass
+
+
+a and "" and False  # SIM223
+
+a and "foo" and False and "bar"  # SIM223
+
+a and 0 and False  # SIM223
+
+a and 1 and False and 2  # SIM223
+
+a and 0.0 and False  # SIM223
+
+a and 0.1 and False and 0.2  # SIM223
+
+a and [] and False  # SIM223
+
+a and list([]) and False  # SIM223
+
+a and [1] and False and [2]  # SIM223
+
+a and list([1]) and False and list([2])  # SIM223
+
+a and {} and False  # SIM223
+
+a and dict() and False  # SIM223
+
+a and {1: 1} and False and {2: 2}  # SIM223
+
+a and dict({1: 1}) and False and dict({2: 2})  # SIM223
+
+a and set() and False  # SIM223
+
+a and set(set()) and False  # SIM223
+
+a and {1} and False and {2}  # SIM223
+
+a and set({1}) and False and set({2})  # SIM223
+
+a and () and False  # SIM222
+
+a and tuple(()) and False  # SIM222
+
+a and (1,) and False and (2,)  # SIM222
+
+a and tuple((1,)) and False and tuple((2,))  # SIM222
+
+a and frozenset() and False  # SIM222
+
+a and frozenset(frozenset()) and False  # SIM222
+
+a and frozenset({1}) and False and frozenset({2})  # SIM222
+
+a and frozenset(frozenset({1})) and False and frozenset(frozenset({2}))  # SIM222
+
+
+# Inside test `a` is simplified.
+
+bool(a and [] and False and [])  # SIM223
+
+assert a and [] and False and []  # SIM223
+
+if (a and [] and False and []) or (a and [] and False and []):  # SIM223
+    pass
+
+0 if a and [] and False and [] else 1  # SIM222
+
+while a and [] and False and []:  # SIM223
+    pass
+
+[
+    0
+    for a in range(10)
+    for b in range(10)
+    if a and [] and False and []  # SIM223
+    if b and [] and False and []  # SIM223
+]
+
+{
+    0
+    for a in range(10)
+    for b in range(10)
+    if a and [] and False and []  # SIM223
+    if b and [] and False and []  # SIM223
+}
+
+{
+    0: 0
+    for a in range(10)
+    for b in range(10)
+    if a and [] and False and []  # SIM223
+    if b and [] and False and []  # SIM223
+}
+
+(
+    0
+    for a in range(10)
+    for b in range(10)
+    if a and [] and False and []  # SIM223
+    if b and [] and False and []  # SIM223
+)
+
+# Outside test `a` is not simplified.
+
+a and [] and False and []  # SIM223
+
+if (a and [] and False and []) == (a and []):  # SIM223
+    pass
+
+if f(a and [] and False and []):  # SIM223
+    pass

crates/ruff/resources/test/fixtures/flake8_tidy_imports/TID251.py

@@ -31,3 +31,6 @@ typing.TypedDict.anything()
 # import aliases are resolved
 import typing as totally_not_typing
 totally_not_typing.TypedDict
+
+# relative imports are respected
+from .typing import TypedDict

crates/ruff/resources/test/fixtures/flake8_tidy_imports/TID251_false_positives.py

@@ -1,11 +0,0 @@
-# module members cannot be imported with that syntax
-import typing.TypedDict
-
-# we don't track reassignments
-import typing, other
-typing = other
-typing.TypedDict()
-
-# yet another false positive
-def foo(typing):
-    typing.TypedDict()

crates/ruff/resources/test/fixtures/flake8_type_checking/strict.py

@@ -1,3 +1,6 @@
+from __future__ import annotations
+
+
 def f():
     # Even in strict mode, this shouldn't rase an error, since `pkg` is used at runtime,
     # and implicitly imports `pkg.bar`.

crates/ruff/resources/test/fixtures/isort/propagate_inline_comments.py

@@ -0,0 +1,4 @@
+from mypackage.subpackage import (  # long comment that seems to be a problem
+    a_long_variable_name_that_causes_problems,
+    items,
+)

crates/ruff/resources/test/fixtures/isort/required_imports/docstring.pyi

@@ -0,0 +1,3 @@
+"""Hello, world!"""
+
+x = 1

crates/ruff/resources/test/fixtures/isort/sections.py

@@ -0,0 +1,7 @@
+from __future__ import annotations
+import os
+import sys
+import pytz
+import django.settings
+from library import foo
+from . import local

crates/ruff/resources/test/fixtures/pep8_naming/N802.py

@@ -39,3 +39,11 @@ class Test(unittest.TestCase):
 
     def testTest(self):
         assert True
+
+
+from typing import override
+
+
+@override
+def BAD_FUNC():
+    pass

crates/ruff/resources/test/fixtures/pep8_naming/N815.py

@@ -13,3 +13,11 @@ class C:
     myObj2 = namedtuple("MyObj2", ["a", "b"])
     Employee = NamedTuple('Employee', [('name', str), ('id', int)])
     Point2D = TypedDict('Point2D', {'in': int, 'x-y': int})
+
+
+class D(TypedDict):
+    lower: int
+    CONSTANT: str
+    mixedCase: bool
+    _mixedCase: list
+    mixed_Case: set

crates/ruff/resources/test/fixtures/pycodestyle/E731.py

@@ -13,6 +13,7 @@ f = lambda: (yield from g())
 class F:
     f = lambda x: 2 * x
 
+
 f = object()
 f.method = lambda: "Method"
 f = {}
@@ -21,3 +22,30 @@ f = []
 f.append(lambda x: x**2)
 f = g = lambda x: x**2
 lambda: "no-op"
+
+# Annotated
+from typing import Callable, ParamSpec
+
+P = ParamSpec("P")
+
+# ParamSpec cannot be used in this context, so do not preserve the annotation.
+f: Callable[P, int] = lambda *args: len(args)
+f: Callable[[], None] = lambda: None
+f: Callable[..., None] = lambda a, b: None
+f: Callable[[int], int] = lambda x: 2 * x
+
+# Let's use the `Callable` type from `collections.abc` instead.
+from collections.abc import Callable
+
+f: Callable[[str, int], str] = lambda a, b: a * b
+f: Callable[[str, int], tuple[str, int]] = lambda a, b: (a, b)
+f: Callable[[str, int, list[str]], list[str]] = lambda a, b, /, c: [*c, a * b]
+
+
+# Override `Callable`
+class Callable:
+    pass
+
+
+# Do not copy the annotation from here on out.
+f: Callable[[str, int], str] = lambda a, b: a * b

crates/ruff/resources/test/fixtures/pycodestyle/W19.py

@@ -97,10 +97,10 @@ if length > options.max_line_length:
 if os.path.exists(os.path.join(path, PEP8_BIN)):
 	cmd = ([os.path.join(path, PEP8_BIN)] +
 	       self._pep8_options(targetfile))
-#: W191
+#: W191 - okay
 '''
 	multiline string with tab in it'''
-#: E101 W191
+#: E101 (W191 okay)
 '''multiline string
 	with tabs
    and spaces
@@ -142,4 +142,10 @@ def test_keys(self):
 x = [
 	'abc'
 ]
-#:
+#: W191 - okay
+'''	multiline string with tab in it, same lines'''
+"""	here we're using '''different delimiters'''"""
+'''
+	multiline string with tab in it, different lines
+'''
+"	single line string with tab in it"

crates/ruff/resources/test/fixtures/pydocstyle/D417.py

@@ -115,6 +115,20 @@ def f(x, *args, **kwargs):
     return x
 
 
+def f(x, *, y, z):
+    """Do something.
+
+    Args:
+        x: some first value
+
+    Keyword Args:
+        y (int): the other value
+        z (int): the last value
+
+    """
+    return x, y, z
+
+
 class Test:
     def f(self, /, arg1: int) -> None:
         """

crates/ruff/resources/test/fixtures/pyflakes/F523.py

@@ -11,3 +11,9 @@
 "{}".format(1, 2, 3)  # F523
 "{:{}}".format(1, 2)  # No issues
 "{:{}}".format(1, 2, 3)  # F523
+
+# With *args
+"{0}{1}".format(*args)  # No issues
+"{0}{1}".format(1, *args)  # No issues
+"{0}{1}".format(1, 2, *args)  # No issues
+"{0}{1}".format(1, 2, 3, *args)  # F523

crates/ruff/resources/test/fixtures/pygrep-hooks/PGH003_0.py

@@ -1,11 +1,16 @@
 x = 1  # type: ignore
-x = 1  # type ignore
 x = 1  # type:ignore
+x = 1  # type: ignore[attr-defined]  # type: ignore
 
 x = 1
+x = 1  # type ignore
 x = 1  # type ignore  # noqa
 x = 1  # type: ignore[attr-defined]
 x = 1  # type: ignore[attr-defined, name-defined]
+x = 1  # type: ignore[attr-defined]  # type: ignore[type-mismatch]
 x = 1  # type: ignore[type-mismatch]  # noqa
+x = 1  # type: ignore [attr-defined]
+x = 1  # type: ignore [attr-defined, name-defined]
+x = 1  # type: ignore [type-mismatch]  # noqa
 x = 1  # type: Union[int, str]
 x = 1  # type: ignoreme

crates/ruff/resources/test/fixtures/pygrep-hooks/PGH003_1.py

@@ -0,0 +1,16 @@
+x = 1  # pyright: ignore
+x = 1  # pyright:ignore
+x = 1  # pyright: ignore[attr-defined]  # pyright: ignore
+
+x = 1
+x = 1  # pyright ignore
+x = 1  # pyright ignore  # noqa
+x = 1  # pyright: ignore[attr-defined]
+x = 1  # pyright: ignore[attr-defined, name-defined]
+x = 1  # pyright: ignore[attr-defined]  # pyright: ignore[type-mismatch]
+x = 1  # pyright: ignore[type-mismatch]  # noqa
+x = 1  # pyright: ignore [attr-defined]
+x = 1  # pyright: ignore [attr-defined, name-defined]
+x = 1  # pyright: ignore [type-mismatch]  # noqa
+x = 1  # pyright: Union[int, str]
+x = 1  # pyright: ignoreme

crates/ruff/resources/test/fixtures/pylint/redefined_loop_name.py

@@ -1,3 +1,6 @@
+import typing
+from typing import cast
+
 # For -> for, variable reused
 for i in []:
     for i in []:  # error
@@ -43,6 +46,9 @@ for i in []:
 
 # For -> assignment
 for i in []:
+    # ignore typing cast
+    i = cast(int, i)
+    i = typing.cast(int, i)
     i = 5  # error
 
 # For -> augmented assignment
@@ -53,6 +59,10 @@ for i in []:
 for i in []:
     i: int = 5  # error
 
+# For -> annotated assignment without value
+for i in []:
+    i: int  # no error
+
 # Async for -> for, variable reused
 async for i in []:
     for i in []:  # error

crates/ruff/resources/test/fixtures/pylint/unexpected_special_method_signature.py

@@ -0,0 +1,51 @@
+class TestClass:
+    def __bool__(self):
+        ...
+    
+    def __bool__(self, x):  # too many mandatory args
+        ...
+    
+    def __bool__(self, x=1):  # additional optional args OK
+        ...
+    
+    def __bool__(self, *args):  # varargs OK
+        ...
+    
+    def __bool__():  # ignored; should be caughty by E0211/N805
+        ...
+    
+    @staticmethod
+    def __bool__():
+        ...
+
+    @staticmethod
+    def __bool__(x):  # too many mandatory args
+        ...
+    
+    @staticmethod
+    def __bool__(x=1):  # additional optional args OK
+        ...
+    
+    def __eq__(self, other):  # multiple args
+        ...
+    
+    def __eq__(self, other=1):  # expected arg is optional
+        ...
+    
+    def __eq__(self):  # too few mandatory args
+        ...
+    
+    def __eq__(self, other, other_other):  # too many mandatory args
+        ...
+    
+    def __round__(self):  # allow zero additional args.
+        ...
+    
+    def __round__(self, x):  # allow one additional args.
+        ...
+    
+    def __round__(self, x, y):  # disallow 2 args
+        ...
+    
+    def __round__(self, x, y, z=2):  # disallow 3 args even when one is optional
+        ...

crates/ruff/resources/test/fixtures/pyupgrade/UP031_0.py

@@ -83,3 +83,26 @@ print('Hello %s (%s)' % bar['bop'])
 print('Hello %(arg)s' % bar)
 print('Hello %(arg)s' % bar.baz)
 print('Hello %(arg)s' % bar['bop'])
+
+# Hanging modulos
+(
+    "foo %s "
+    "bar %s"
+) % (x, y)
+
+(
+    "foo %(foo)s "
+    "bar %(bar)s"
+) % {"foo": x, "bar": y}
+
+(
+    """foo %s"""
+    % (x,)
+)
+
+(
+    """
+    foo %s
+    """
+    % (x,)
+)

crates/ruff/resources/test/fixtures/pyupgrade/UP031_1.py

@@ -34,28 +34,6 @@ pytest.param('"%8s" % (None,)', id="unsafe width-string conversion"),
 "%(and)s" % {"and": 2}
 
 # OK (arguably false negatives)
-(
-    "foo %s "
-    "bar %s"
-) % (x, y)
-
-(
-    "foo %(foo)s "
-    "bar %(bar)s"
-) % {"foo": x, "bar": y}
-
-(
-    """foo %s"""
-    % (x,)
-)
-
-(
-    """
-    foo %s
-    """
-    % (x,)
-)
-
 'Hello %s' % bar
 
 'Hello %s' % bar.baz

crates/ruff/resources/test/fixtures/ruff/RUF008.py

@@ -0,0 +1,27 @@
+import typing
+from dataclasses import dataclass, field
+from typing import ClassVar, Sequence
+
+KNOWINGLY_MUTABLE_DEFAULT = []
+
+
+@dataclass()
+class A:
+    mutable_default: list[int] = []
+    immutable_annotation: typing.Sequence[int] = []
+    without_annotation = []
+    ignored_via_comment: list[int] = []  # noqa: RUF008
+    correct_code: list[int] = KNOWINGLY_MUTABLE_DEFAULT
+    perfectly_fine: list[int] = field(default_factory=list)
+    class_variable: typing.ClassVar[list[int]] = []
+
+
+@dataclass
+class B:
+    mutable_default: list[int] = []
+    immutable_annotation: Sequence[int] = []
+    without_annotation = []
+    ignored_via_comment: list[int] = []  # noqa: RUF008
+    correct_code: list[int] = KNOWINGLY_MUTABLE_DEFAULT
+    perfectly_fine: list[int] = field(default_factory=list)
+    class_variable: ClassVar[list[int]] = []

crates/ruff/resources/test/fixtures/ruff/RUF009.py

@@ -0,0 +1,31 @@
+import typing
+from dataclasses import dataclass
+from typing import ClassVar, NamedTuple
+
+
+def default_function() -> list[int]:
+    return []
+
+
+class ImmutableType(NamedTuple):
+    something: int = 8
+
+
+@dataclass()
+class A:
+    hidden_mutable_default: list[int] = default_function()
+    class_variable: typing.ClassVar[list[int]] = default_function()
+    another_class_var: ClassVar[list[int]] = default_function()
+
+
+DEFAULT_IMMUTABLETYPE_FOR_ALL_DATACLASSES = ImmutableType(40)
+DEFAULT_A_FOR_ALL_DATACLASSES = A([1, 2, 3])
+
+
+@dataclass
+class B:
+    hidden_mutable_default: list[int] = default_function()
+    another_dataclass: A = A()
+    not_optimal: ImmutableType = ImmutableType(20)
+    good_variant: ImmutableType = DEFAULT_IMMUTABLETYPE_FOR_ALL_DATACLASSES
+    okay_variant: A = DEFAULT_A_FOR_ALL_DATACLASSES

crates/ruff/src/autofix/actions.rs

@@ -103,7 +103,7 @@ fn is_lone_child(child: &Stmt, parent: &Stmt, deleted: &[&Stmt]) -> Result<bool>
 /// Return the location of a trailing semicolon following a `Stmt`, if it's part
 /// of a multi-statement line.
 fn trailing_semicolon(stmt: &Stmt, locator: &Locator) -> Option<Location> {
-    let contents = locator.skip(stmt.end_location.unwrap());
+    let contents = locator.after(stmt.end_location.unwrap());
     for (row, line) in NewlineWithTrailingNewline::from(contents).enumerate() {
         let trimmed = line.trim();
         if trimmed.starts_with(';') {
@@ -126,7 +126,7 @@ fn trailing_semicolon(stmt: &Stmt, locator: &Locator) -> Option<Location> {
 /// Find the next valid break for a `Stmt` after a semicolon.
 fn next_stmt_break(semicolon: Location, locator: &Locator) -> Location {
     let start_location = Location::new(semicolon.row(), semicolon.column() + 1);
-    let contents = locator.skip(start_location);
+    let contents = locator.after(start_location);
     for (row, line) in NewlineWithTrailingNewline::from(contents).enumerate() {
         let trimmed = line.trim();
         // Skip past any continuations.
@@ -158,7 +158,7 @@ fn next_stmt_break(semicolon: Location, locator: &Locator) -> Location {
 
 /// Return `true` if a `Stmt` occurs at the end of a file.
 fn is_end_of_file(stmt: &Stmt, locator: &Locator) -> bool {
-    let contents = locator.skip(stmt.end_location.unwrap());
+    let contents = locator.after(stmt.end_location.unwrap());
     contents.is_empty()
 }
 
@@ -361,7 +361,7 @@ pub fn remove_argument(
     remove_parentheses: bool,
 ) -> Result<Edit> {
     // TODO(sbrugman): Preserve trailing comments.
-    let contents = locator.skip(call_at);
+    let contents = locator.after(call_at);
 
     let mut fix_start = None;
     let mut fix_end = None;

crates/ruff/src/autofix/mod.rs

@@ -15,10 +15,15 @@ pub mod actions;
 
 /// Auto-fix errors in a file, and write the fixed source code to disk.
 pub fn fix_file(diagnostics: &[Diagnostic], locator: &Locator) -> Option<(String, FixTable)> {
-    if diagnostics.iter().all(|check| check.fix.is_empty()) {
+    let mut with_fixes = diagnostics
+        .iter()
+        .filter(|diag| !diag.fix.is_empty())
+        .peekable();
+
+    if with_fixes.peek().is_none() {
         None
     } else {
-        Some(apply_fixes(diagnostics.iter(), locator))
+        Some(apply_fixes(with_fixes, locator))
     }
 }
 
@@ -52,7 +57,7 @@ fn apply_fixes<'a>(
         // Best-effort approach: if this fix overlaps with a fix we've already applied,
         // skip it.
         if last_pos.map_or(false, |last_pos| {
-            fix.location()
+            fix.min_location()
                 .map_or(false, |fix_location| last_pos >= fix_location)
         }) {
             continue;
@@ -60,14 +65,14 @@ fn apply_fixes<'a>(
 
         for edit in fix.edits() {
             // Add all contents from `last_pos` to `fix.location`.
-            let slice = locator.slice(Range::new(last_pos.unwrap_or_default(), edit.location));
+            let slice = locator.slice(Range::new(last_pos.unwrap_or_default(), edit.location()));
             output.push_str(slice);
 
             // Add the patch itself.
-            output.push_str(&edit.content);
+            output.push_str(edit.content().unwrap_or_default());
 
             // Track that the edit was applied.
-            last_pos = Some(edit.end_location);
+            last_pos = Some(edit.end_location());
             applied.insert(edit);
         }
 
@@ -75,7 +80,7 @@ fn apply_fixes<'a>(
     }
 
     // Add the remaining content.
-    let slice = locator.skip(last_pos.unwrap_or_default());
+    let slice = locator.after(last_pos.unwrap_or_default());
     output.push_str(slice);
 
     (output, fixed)
@@ -83,8 +88,8 @@ fn apply_fixes<'a>(
 
 /// Compare two fixes.
 fn cmp_fix(rule1: Rule, rule2: Rule, fix1: &Fix, fix2: &Fix) -> std::cmp::Ordering {
-    fix1.location()
-        .cmp(&fix2.location())
+    fix1.min_location()
+        .cmp(&fix2.min_location())
         .then_with(|| match (&rule1, &rule2) {
             // Apply `EndsInPeriod` fixes before `NewLineAfterLastParagraph` fixes.
             (Rule::EndsInPeriod, Rule::NewLineAfterLastParagraph) => std::cmp::Ordering::Less,
@@ -109,8 +114,8 @@ mod tests {
             .map(|edit| Diagnostic {
                 // The choice of rule here is arbitrary.
                 kind: MissingNewlineAtEndOfFile.into(),
-                location: edit.location,
-                end_location: edit.end_location,
+                location: edit.location(),
+                end_location: edit.end_location(),
                 fix: edit.into(),
                 parent: None,
             })
@@ -135,11 +140,11 @@ class A(object):
 "#
             .trim(),
         );
-        let diagnostics = create_diagnostics([Edit {
-            content: "Bar".to_string(),
-            location: Location::new(1, 8),
-            end_location: Location::new(1, 14),
-        }]);
+        let diagnostics = create_diagnostics([Edit::replacement(
+            "Bar".to_string(),
+            Location::new(1, 8),
+            Location::new(1, 14),
+        )]);
         let (contents, fixed) = apply_fixes(diagnostics.iter(), &locator);
         assert_eq!(
             contents,
@@ -161,11 +166,8 @@ class A(object):
 "#
             .trim(),
         );
-        let diagnostics = create_diagnostics([Edit {
-            content: String::new(),
-            location: Location::new(1, 7),
-            end_location: Location::new(1, 15),
-        }]);
+        let diagnostics =
+            create_diagnostics([Edit::deletion(Location::new(1, 7), Location::new(1, 15))]);
         let (contents, fixed) = apply_fixes(diagnostics.iter(), &locator);
         assert_eq!(
             contents,
@@ -188,16 +190,8 @@ class A(object, object, object):
             .trim(),
         );
         let diagnostics = create_diagnostics([
-            Edit {
-                content: String::new(),
-                location: Location::new(1, 8),
-                end_location: Location::new(1, 16),
-            },
-            Edit {
-                content: String::new(),
-                location: Location::new(1, 22),
-                end_location: Location::new(1, 30),
-            },
+            Edit::deletion(Location::new(1, 8), Location::new(1, 16)),
+            Edit::deletion(Location::new(1, 22), Location::new(1, 30)),
         ]);
         let (contents, fixed) = apply_fixes(diagnostics.iter(), &locator);
 
@@ -222,16 +216,12 @@ class A(object):
             .trim(),
         );
         let diagnostics = create_diagnostics([
-            Edit {
-                content: String::new(),
-                location: Location::new(1, 7),
-                end_location: Location::new(1, 15),
-            },
-            Edit {
-                content: "ignored".to_string(),
-                location: Location::new(1, 9),
-                end_location: Location::new(1, 11),
-            },
+            Edit::deletion(Location::new(1, 7), Location::new(1, 15)),
+            Edit::replacement(
+                "ignored".to_string(),
+                Location::new(1, 9),
+                Location::new(1, 11),
+            ),
         ]);
         let (contents, fixed) = apply_fixes(diagnostics.iter(), &locator);
         assert_eq!(

crates/ruff/src/checkers/ast/mod.rs

@@ -161,6 +161,18 @@ macro_rules! visit_non_type_definition {
     }};
 }
 
+/// Visit an [`Expr`], and treat it as a boolean test. This is useful for detecting whether an
+/// expressions return value is significant, or whether the calling context only relies on
+/// its truthiness.
+macro_rules! visit_boolean_test {
+    ($self:ident, $expr:expr) => {{
+        let prev_in_boolean_test = $self.ctx.in_boolean_test;
+        $self.ctx.in_boolean_test = true;
+        $self.visit_expr($expr);
+        $self.ctx.in_boolean_test = prev_in_boolean_test;
+    }};
+}
+
 impl<'a, 'b> Visitor<'b> for Checker<'a>
 where
     'b: 'a,
@@ -344,6 +356,7 @@ where
                             |expr| self.ctx.resolve_call_path(expr),
                         ));
                 }
+
                 if self.settings.rules.enabled(Rule::AmbiguousFunctionName) {
                     if let Some(diagnostic) =
                         pycodestyle::rules::ambiguous_function_name(name, || {
@@ -358,7 +371,9 @@ where
                     if let Some(diagnostic) = pep8_naming::rules::invalid_function_name(
                         stmt,
                         name,
+                        decorator_list,
                         &self.settings.pep8_naming.ignore_names,
+                        &self.ctx,
                         self.locator,
                     ) {
                         self.diagnostics.push(diagnostic);
@@ -587,6 +602,21 @@ where
                     );
                 }
 
+                if self
+                    .settings
+                    .rules
+                    .enabled(Rule::UnexpectedSpecialMethodSignature)
+                {
+                    pylint::rules::unexpected_special_method_signature(
+                        self,
+                        stmt,
+                        name,
+                        decorator_list,
+                        args,
+                        self.locator,
+                    );
+                }
+
                 self.check_builtin_shadowing(name, stmt, true);
 
                 // Visit the decorators and arguments, but avoid the body, which will be
@@ -595,14 +625,9 @@ where
                     self.visit_expr(expr);
                 }
 
-                // If we're in a class or module scope, then the annotation needs to be
-                // available at runtime.
-                // See: https://docs.python.org/3/reference/simple_stmts.html#annotated-assignment-statements
-                let runtime_annotation = !self.ctx.annotations_future_enabled
-                    && matches!(
-                        self.ctx.scope().kind,
-                        ScopeKind::Class(..) | ScopeKind::Module
-                    );
+                // Function annotations are always evaluated at runtime, unless future annotations
+                // are enabled.
+                let runtime_annotation = !self.ctx.annotations_future_enabled;
 
                 for arg in &args.posonlyargs {
                     if let Some(expr) = &arg.node.annotation {
@@ -816,6 +841,24 @@ where
                     flake8_pie::rules::non_unique_enums(self, stmt, body);
                 }
 
+                if self.settings.rules.any_enabled(&[
+                    Rule::MutableDataclassDefault,
+                    Rule::FunctionCallInDataclassDefaultArgument,
+                ]) && ruff::rules::is_dataclass(self, decorator_list)
+                {
+                    if self.settings.rules.enabled(Rule::MutableDataclassDefault) {
+                        ruff::rules::mutable_dataclass_default(self, body);
+                    }
+
+                    if self
+                        .settings
+                        .rules
+                        .enabled(Rule::FunctionCallInDataclassDefaultArgument)
+                    {
+                        ruff::rules::function_call_in_dataclass_defaults(self, body);
+                    }
+                }
+
                 self.check_builtin_shadowing(name, stmt, false);
 
                 for expr in bases {
@@ -949,15 +992,11 @@ where
 
                     // flake8_tidy_imports
                     if self.settings.rules.enabled(Rule::BannedApi) {
-                        if let Some(diagnostic) =
-                            flake8_tidy_imports::banned_api::name_or_parent_is_banned(
-                                alias,
-                                &alias.node.name,
-                                &self.settings.flake8_tidy_imports.banned_api,
-                            )
-                        {
-                            self.diagnostics.push(diagnostic);
-                        }
+                        flake8_tidy_imports::banned_api::name_or_parent_is_banned(
+                            self,
+                            &alias.node.name,
+                            alias,
+                        );
                     }
 
                     // pylint
@@ -1045,7 +1084,7 @@ where
 
                     if self.settings.rules.enabled(Rule::UnconventionalImportAlias) {
                         if let Some(diagnostic) =
-                            flake8_import_conventions::rules::check_conventional_import(
+                            flake8_import_conventions::rules::conventional_import_alias(
                                 stmt,
                                 &alias.node.name,
                                 alias.node.asname.as_deref(),
@@ -1056,6 +1095,21 @@ where
                         }
                     }
 
+                    if self.settings.rules.enabled(Rule::BannedImportAlias) {
+                        if let Some(asname) = &alias.node.asname {
+                            if let Some(diagnostic) =
+                                flake8_import_conventions::rules::banned_import_alias(
+                                    stmt,
+                                    &alias.node.name,
+                                    asname,
+                                    &self.settings.flake8_import_conventions.banned_aliases,
+                                )
+                            {
+                                self.diagnostics.push(diagnostic);
+                            }
+                        }
+                    }
+
                     if self
                         .settings
                         .rules
@@ -1123,26 +1177,24 @@ where
                 }
 
                 if self.settings.rules.enabled(Rule::BannedApi) {
-                    if let Some(module) = module {
-                        for name in names {
-                            if let Some(diagnostic) =
-                                flake8_tidy_imports::banned_api::name_is_banned(
-                                    module,
-                                    name,
-                                    &self.settings.flake8_tidy_imports.banned_api,
-                                )
-                            {
-                                self.diagnostics.push(diagnostic);
+                    if let Some(module) = helpers::resolve_imported_module_path(
+                        *level,
+                        module.as_deref(),
+                        self.module_path.as_deref(),
+                    ) {
+                        flake8_tidy_imports::banned_api::name_or_parent_is_banned(
+                            self, &module, stmt,
+                        );
+
+                        for alias in names {
+                            if alias.node.name == "*" {
+                                continue;
                             }
-                        }
-                        if let Some(diagnostic) =
-                            flake8_tidy_imports::banned_api::name_or_parent_is_banned(
-                                stmt,
-                                module,
-                                &self.settings.flake8_tidy_imports.banned_api,
-                            )
-                        {
-                            self.diagnostics.push(diagnostic);
+                            flake8_tidy_imports::banned_api::name_is_banned(
+                                self,
+                                format!("{module}.{}", alias.node.name),
+                                alias,
+                            );
                         }
                     }
                 }
@@ -1281,7 +1333,7 @@ where
                                 stmt,
                                 *level,
                                 module.as_deref(),
-                                self.module_path.as_ref(),
+                                self.module_path.as_deref(),
                                 &self.settings.flake8_tidy_imports.ban_relative_imports,
                             )
                         {
@@ -1307,7 +1359,7 @@ where
                             &alias.node.name,
                         );
                         if let Some(diagnostic) =
-                            flake8_import_conventions::rules::check_conventional_import(
+                            flake8_import_conventions::rules::conventional_import_alias(
                                 stmt,
                                 &full_name,
                                 alias.node.asname.as_deref(),
@@ -1318,6 +1370,26 @@ where
                         }
                     }
 
+                    if self.settings.rules.enabled(Rule::BannedImportAlias) {
+                        if let Some(asname) = &alias.node.asname {
+                            let full_name = helpers::format_import_from_member(
+                                *level,
+                                module.as_deref(),
+                                &alias.node.name,
+                            );
+                            if let Some(diagnostic) =
+                                flake8_import_conventions::rules::banned_import_alias(
+                                    stmt,
+                                    &full_name,
+                                    asname,
+                                    &self.settings.flake8_import_conventions.banned_aliases,
+                                )
+                            {
+                                self.diagnostics.push(diagnostic);
+                            }
+                        }
+                    }
+
                     if let Some(asname) = &alias.node.asname {
                         if self
                             .settings
@@ -1412,6 +1484,16 @@ where
                         }
                     }
                 }
+
+                if self.settings.rules.enabled(Rule::BannedImportFrom) {
+                    if let Some(diagnostic) = flake8_import_conventions::rules::banned_import_from(
+                        stmt,
+                        &helpers::format_import_from(*level, module.as_deref()),
+                        &self.settings.flake8_import_conventions.banned_from,
+                    ) {
+                        self.diagnostics.push(diagnostic);
+                    }
+                }
             }
             StmtKind::Raise { exc, .. } => {
                 if self.settings.rules.enabled(Rule::RaiseNotImplemented) {
@@ -1547,20 +1629,20 @@ where
                 }
             }
             StmtKind::Assert { test, msg } => {
+                if !self.ctx.in_type_checking_block {
+                    if self.settings.rules.enabled(Rule::Assert) {
+                        self.diagnostics
+                            .push(flake8_bandit::rules::assert_used(stmt));
+                    }
+                }
                 if self.settings.rules.enabled(Rule::AssertTuple) {
                     pyflakes::rules::assert_tuple(self, stmt, test);
                 }
                 if self.settings.rules.enabled(Rule::AssertFalse) {
                     flake8_bugbear::rules::assert_false(self, stmt, test, msg.as_deref());
                 }
-                if self.settings.rules.enabled(Rule::Assert) {
-                    self.diagnostics
-                        .push(flake8_bandit::rules::assert_used(stmt));
-                }
                 if self.settings.rules.enabled(Rule::PytestAssertAlwaysFalse) {
-                    if let Some(diagnostic) = flake8_pytest_style::rules::assert_falsy(stmt, test) {
-                        self.diagnostics.push(diagnostic);
-                    }
+                    flake8_pytest_style::rules::assert_falsy(self, stmt, test);
                 }
                 if self.settings.rules.enabled(Rule::PytestCompositeAssertion) {
                     flake8_pytest_style::rules::composite_condition(
@@ -1570,7 +1652,6 @@ where
                         msg.as_deref(),
                     );
                 }
-
                 if self.settings.rules.enabled(Rule::AssertOnStringLiteral) {
                     pylint::rules::assert_on_string_literal(self, test);
                 }
@@ -1729,7 +1810,7 @@ where
             StmtKind::Assign { targets, value, .. } => {
                 if self.settings.rules.enabled(Rule::LambdaAssignment) {
                     if let [target] = &targets[..] {
-                        pycodestyle::rules::lambda_assignment(self, target, value, stmt);
+                        pycodestyle::rules::lambda_assignment(self, target, value, None, stmt);
                     }
                 }
 
@@ -1745,12 +1826,6 @@ where
                     }
                 }
 
-                if self.is_stub {
-                    if self.settings.rules.enabled(Rule::UnprefixedTypeParam) {
-                        flake8_pyi::rules::prefix_type_params(self, value, targets);
-                    }
-                }
-
                 if self.settings.rules.enabled(Rule::GlobalStatement) {
                     for target in targets.iter() {
                         if let ExprKind::Name { id, .. } = &target.node {
@@ -1791,8 +1866,20 @@ where
                 }
 
                 if self.is_stub {
-                    if self.settings.rules.enabled(Rule::AssignmentDefaultInStub) {
-                        flake8_pyi::rules::assignment_default_in_stub(self, value, None);
+                    if self
+                        .settings
+                        .rules
+                        .any_enabled(&[Rule::UnprefixedTypeParam, Rule::AssignmentDefaultInStub])
+                    {
+                        // Ignore assignments in function bodies; those are covered by other rules.
+                        if !self.ctx.scopes().any(|scope| scope.kind.is_function()) {
+                            if self.settings.rules.enabled(Rule::UnprefixedTypeParam) {
+                                flake8_pyi::rules::prefix_type_params(self, value, targets);
+                            }
+                            if self.settings.rules.enabled(Rule::AssignmentDefaultInStub) {
+                                flake8_pyi::rules::assignment_default_in_stub(self, targets, value);
+                            }
+                        }
                     }
                 }
             }
@@ -1804,7 +1891,13 @@ where
             } => {
                 if self.settings.rules.enabled(Rule::LambdaAssignment) {
                     if let Some(value) = value {
-                        pycodestyle::rules::lambda_assignment(self, target, value, stmt);
+                        pycodestyle::rules::lambda_assignment(
+                            self,
+                            target,
+                            value,
+                            Some(annotation),
+                            stmt,
+                        );
                     }
                 }
                 if self
@@ -1822,11 +1915,12 @@ where
                 if self.is_stub {
                     if let Some(value) = value {
                         if self.settings.rules.enabled(Rule::AssignmentDefaultInStub) {
-                            flake8_pyi::rules::assignment_default_in_stub(
-                                self,
-                                value,
-                                Some(annotation),
-                            );
+                            // Ignore assignments in function bodies; those are covered by other rules.
+                            if !self.ctx.scopes().any(|scope| scope.kind.is_function()) {
+                                flake8_pyi::rules::annotated_assignment_default_in_stub(
+                                    self, target, value, annotation,
+                                );
+                            }
                         }
                     }
                 }
@@ -2087,8 +2181,19 @@ where
                 }
                 self.visit_expr(target);
             }
+            StmtKind::Assert { test, msg } => {
+                visit_boolean_test!(self, test);
+                if let Some(expr) = msg {
+                    self.visit_expr(expr);
+                }
+            }
+            StmtKind::While { test, body, orelse } => {
+                visit_boolean_test!(self, test);
+                self.visit_body(body);
+                self.visit_body(orelse);
+            }
             StmtKind::If { test, body, orelse } => {
-                self.visit_expr(test);
+                visit_boolean_test!(self, test);
 
                 if flake8_type_checking::helpers::is_type_checking_block(&self.ctx, test) {
                     if self.settings.rules.enabled(Rule::EmptyTypeCheckingBlock) {
@@ -2175,6 +2280,11 @@ where
 
         let prev_in_literal = self.ctx.in_literal;
         let prev_in_type_definition = self.ctx.in_type_definition;
+        let prev_in_boolean_test = self.ctx.in_boolean_test;
+
+        if !matches!(expr.node, ExprKind::BoolOp { .. }) {
+            self.ctx.in_boolean_test = false;
+        }
 
         // Pre-visit.
         match &expr.node {
@@ -2528,13 +2638,6 @@ where
                 if self.settings.rules.enabled(Rule::UnnecessaryDictKwargs) {
                     flake8_pie::rules::unnecessary_dict_kwargs(self, expr, keywords);
                 }
-                if self
-                    .settings
-                    .rules
-                    .enabled(Rule::UnnecessaryComprehensionAnyAll)
-                {
-                    flake8_pie::rules::unnecessary_comprehension_any_all(self, expr, func, args);
-                }
 
                 // flake8-bandit
                 if self.settings.rules.enabled(Rule::ExecBuiltin) {
@@ -2594,6 +2697,16 @@ where
                         self, func, args, keywords,
                     );
                 }
+                if self.settings.rules.any_enabled(&[
+                    Rule::SubprocessWithoutShellEqualsTrue,
+                    Rule::SubprocessPopenWithShellEqualsTrue,
+                    Rule::CallWithShellEqualsTrue,
+                    Rule::StartProcessWithAShell,
+                    Rule::StartProcessWithNoShell,
+                    Rule::StartProcessWithPartialPath,
+                ]) {
+                    flake8_bandit::rules::shell_injection(self, func, args, keywords);
+                }
 
                 // flake8-comprehensions
                 if self.settings.rules.enabled(Rule::UnnecessaryGeneratorList) {
@@ -2665,7 +2778,7 @@ where
                     .enabled(Rule::UnnecessaryLiteralWithinTupleCall)
                 {
                     flake8_comprehensions::rules::unnecessary_literal_within_tuple_call(
-                        self, expr, func, args,
+                        self, expr, func, args, keywords,
                     );
                 }
                 if self
@@ -2674,7 +2787,16 @@ where
                     .enabled(Rule::UnnecessaryLiteralWithinListCall)
                 {
                     flake8_comprehensions::rules::unnecessary_literal_within_list_call(
-                        self, expr, func, args,
+                        self, expr, func, args, keywords,
+                    );
+                }
+                if self
+                    .settings
+                    .rules
+                    .enabled(Rule::UnnecessaryLiteralWithinDictCall)
+                {
+                    flake8_comprehensions::rules::unnecessary_literal_within_dict_call(
+                        self, expr, func, args, keywords,
                     );
                 }
                 if self.settings.rules.enabled(Rule::UnnecessaryListCall) {
@@ -2716,6 +2838,15 @@ where
                         args,
                     );
                 }
+                if self
+                    .settings
+                    .rules
+                    .enabled(Rule::UnnecessaryComprehensionAnyAll)
+                {
+                    flake8_comprehensions::rules::unnecessary_comprehension_any_all(
+                        self, expr, func, args, keywords,
+                    );
+                }
 
                 // flake8-boolean-trap
                 if self
@@ -3178,7 +3309,7 @@ where
                     }
 
                     if self.settings.rules.enabled(Rule::PrintfStringFormatting) {
-                        pyupgrade::rules::printf_string_formatting(self, expr, left, right);
+                        pyupgrade::rules::printf_string_formatting(self, expr, right);
                     }
                     if self.settings.rules.enabled(Rule::BadStringFormatType) {
                         pylint::rules::bad_string_format_type(self, expr, right);
@@ -3211,6 +3342,27 @@ where
                     flake8_bandit::rules::hardcoded_sql_expression(self, expr);
                 }
             }
+            ExprKind::BinOp {
+                op: Operator::BitOr,
+                ..
+            } => {
+                if self.is_stub {
+                    if self.settings.rules.enabled(Rule::DuplicateUnionMember)
+                        && self.ctx.in_type_definition
+                        && self.ctx.current_expr_parent().map_or(true, |parent| {
+                            !matches!(
+                                parent.node,
+                                ExprKind::BinOp {
+                                    op: Operator::BitOr,
+                                    ..
+                                }
+                            )
+                        })
+                    {
+                        flake8_pyi::rules::duplicate_union_member(self, expr);
+                    }
+                }
+            }
             ExprKind::UnaryOp { op, operand } => {
                 let check_not_in = self.settings.rules.enabled(Rule::NotInTest);
                 let check_not_is = self.settings.rules.enabled(Rule::NotIsTest);
@@ -3473,6 +3625,11 @@ where
                     (self.ctx.scope_stack.clone(), self.ctx.parents.clone()),
                 ));
             }
+            ExprKind::IfExp { test, body, orelse } => {
+                visit_boolean_test!(self, test);
+                self.visit_expr(body);
+                self.visit_expr(orelse);
+            }
             ExprKind::Call {
                 func,
                 args,
@@ -3501,11 +3658,22 @@ where
                     .any(|target| call_path.as_slice() == ["mypy_extensions", target])
                     {
                         Some(Callable::MypyExtension)
+                    } else if call_path.as_slice() == ["", "bool"] {
+                        Some(Callable::Bool)
                     } else {
                         None
                     }
                 });
                 match callable {
+                    Some(Callable::Bool) => {
+                        self.visit_expr(func);
+                        if !args.is_empty() {
+                            visit_boolean_test!(self, &args[0]);
+                        }
+                        for expr in args.iter().skip(1) {
+                            self.visit_expr(expr);
+                        }
+                    }
                     Some(Callable::Cast) => {
                         self.visit_expr(func);
                         if !args.is_empty() {
@@ -3704,6 +3872,7 @@ where
 
         self.ctx.in_type_definition = prev_in_type_definition;
         self.ctx.in_literal = prev_in_literal;
+        self.ctx.in_boolean_test = prev_in_boolean_test;
 
         self.ctx.pop_expr();
     }
@@ -3716,7 +3885,11 @@ where
                 &comprehension.iter,
             );
         }
-        visitor::walk_comprehension(self, comprehension);
+        self.visit_expr(&comprehension.iter);
+        self.visit_expr(&comprehension.target);
+        for expr in &comprehension.ifs {
+            visit_boolean_test!(self, expr);
+        }
     }
 
     fn visit_excepthandler(&mut self, excepthandler: &'b Excepthandler) {
@@ -4355,8 +4528,14 @@ impl<'a> Checker<'a> {
             .rules
             .enabled(Rule::MixedCaseVariableInClassScope)
         {
-            if matches!(self.ctx.scope().kind, ScopeKind::Class(..)) {
-                pep8_naming::rules::mixed_case_variable_in_class_scope(self, expr, parent, id);
+            if let ScopeKind::Class(class) = &self.ctx.scope().kind {
+                pep8_naming::rules::mixed_case_variable_in_class_scope(
+                    self,
+                    expr,
+                    parent,
+                    id,
+                    class.bases,
+                );
             }
         }
 
@@ -4387,7 +4566,6 @@ impl<'a> Checker<'a> {
             return;
         }
 
-        // TODO(charlie): Include comprehensions here.
         if matches!(
             parent.node,
             StmtKind::For { .. } | StmtKind::AsyncFor { .. }
@@ -5083,7 +5261,7 @@ impl<'a> Checker<'a> {
                             self.stylist,
                         ) {
                             Ok(fix) => {
-                                if fix.content.is_empty() || fix.content == "pass" {
+                                if fix.is_deletion() || fix.content() == Some("pass") {
                                     self.deletions.insert(*defined_by);
                                 }
                                 Some(fix)

crates/ruff/src/checkers/imports.rs

@@ -9,6 +9,7 @@ use ruff_python_ast::helpers::to_module_path;
 use ruff_python_ast::imports::{ImportMap, ModuleImport};
 use ruff_python_ast::source_code::{Indexer, Locator, Stylist};
 use ruff_python_ast::visitor::Visitor;
+use ruff_python_stdlib::path::is_python_stub_file;
 
 use crate::directives::IsortDirectives;
 use crate::registry::Rule;
@@ -88,9 +89,11 @@ pub fn check_imports(
     path: &Path,
     package: Option<&Path>,
 ) -> (Vec<Diagnostic>, Option<ImportMap>) {
+    let is_stub = is_python_stub_file(path);
+
     // Extract all imports from the AST.
     let tracker = {
-        let mut tracker = ImportTracker::new(locator, directives, path);
+        let mut tracker = ImportTracker::new(locator, directives, is_stub);
         tracker.visit_body(python_ast);
         tracker
     };
@@ -111,7 +114,7 @@ pub fn check_imports(
     }
     if settings.rules.enabled(Rule::MissingRequiredImport) {
         diagnostics.extend(isort::rules::add_required_imports(
-            &blocks, python_ast, locator, stylist, settings, autofix,
+            &blocks, python_ast, locator, stylist, settings, autofix, is_stub,
         ));
     }
 

crates/ruff/src/checkers/logical_lines.rs

@@ -183,7 +183,7 @@ pub fn check_logical_lines(
             if settings.rules.enabled(kind.rule()) {
                 diagnostics.push(Diagnostic {
                     kind,
-                    location,
+                    location: Location::new(start_loc.row(), 0),
                     end_location: location,
                     fix: Fix::empty(),
                     parent: None,

crates/ruff/src/checkers/physical_lines.rs

@@ -4,7 +4,7 @@ use std::path::Path;
 
 use ruff_diagnostics::Diagnostic;
 use ruff_python_ast::newlines::StrExt;
-use ruff_python_ast::source_code::{Locator, Stylist};
+use ruff_python_ast::source_code::{Indexer, Locator, Stylist};
 
 use crate::registry::Rule;
 use crate::rules::flake8_executable::helpers::{extract_shebang, ShebangDirective};
@@ -24,7 +24,7 @@ pub fn check_physical_lines(
     path: &Path,
     locator: &Locator,
     stylist: &Stylist,
-    commented_lines: &[usize],
+    indexer: &Indexer,
     doc_lines: &[usize],
     settings: &Settings,
     autofix: flags::Autofix,
@@ -55,8 +55,11 @@ pub fn check_physical_lines(
     let fix_shebang_whitespace =
         autofix.into() && settings.rules.should_fix(Rule::ShebangLeadingWhitespace);
 
-    let mut commented_lines_iter = commented_lines.iter().peekable();
+    let mut commented_lines_iter = indexer.commented_lines().iter().peekable();
     let mut doc_lines_iter = doc_lines.iter().peekable();
+
+    let string_lines = indexer.string_ranges();
+
     for (index, line) in locator.contents().universal_newlines().enumerate() {
         while commented_lines_iter
             .next_if(|lineno| &(index + 1) == *lineno)
@@ -73,15 +76,11 @@ pub fn check_physical_lines(
             }
 
             if enforce_blanket_type_ignore {
-                if let Some(diagnostic) = blanket_type_ignore(index, line) {
-                    diagnostics.push(diagnostic);
-                }
+                blanket_type_ignore(&mut diagnostics, index, line);
             }
 
             if enforce_blanket_noqa {
-                if let Some(diagnostic) = blanket_noqa(index, line) {
-                    diagnostics.push(diagnostic);
-                }
+                blanket_noqa(&mut diagnostics, index, line);
             }
 
             if enforce_shebang_missing
@@ -155,7 +154,7 @@ pub fn check_physical_lines(
         }
 
         if enforce_tab_indentation {
-            if let Some(diagnostic) = tab_indentation(index, line) {
+            if let Some(diagnostic) = tab_indentation(index + 1, line, string_lines) {
                 diagnostics.push(diagnostic);
             }
         }
@@ -186,7 +185,7 @@ mod tests {
     use rustpython_parser::Mode;
     use std::path::Path;
 
-    use ruff_python_ast::source_code::{Locator, Stylist};
+    use ruff_python_ast::source_code::{Indexer, Locator, Stylist};
 
     use crate::registry::Rule;
     use crate::settings::{flags, Settings};
@@ -198,6 +197,7 @@ mod tests {
         let line = "'\u{4e9c}' * 2"; // 7 in UTF-32, 9 in UTF-8.
         let locator = Locator::new(line);
         let tokens: Vec<_> = lex(line, Mode::Module).collect();
+        let indexer: Indexer = tokens.as_slice().into();
         let stylist = Stylist::from_tokens(&tokens, &locator);
 
         let check_with_max_line_length = |line_length: usize| {
@@ -205,7 +205,7 @@ mod tests {
                 Path::new("foo.py"),
                 &locator,
                 &stylist,
-                &[],
+                &indexer,
                 &[],
                 &Settings {
                     line_length,

crates/ruff/src/codes.rs

@@ -202,6 +202,7 @@ pub fn code_to_rule(linter: Linter, code: &str) -> Option<Rule> {
         (Pylint, "W0711") => Rule::BinaryOpException,
         (Pylint, "W1508") => Rule::InvalidEnvvarDefault,
         (Pylint, "W2901") => Rule::RedefinedLoopName,
+        (Pylint, "E0302") => Rule::UnexpectedSpecialMethodSignature,
 
         // flake8-builtins
         (Flake8Builtins, "001") => Rule::BuiltinVariableShadowing,
@@ -263,6 +264,8 @@ pub fn code_to_rule(linter: Linter, code: &str) -> Option<Rule> {
         (Flake8Comprehensions, "15") => Rule::UnnecessarySubscriptReversal,
         (Flake8Comprehensions, "16") => Rule::UnnecessaryComprehension,
         (Flake8Comprehensions, "17") => Rule::UnnecessaryMap,
+        (Flake8Comprehensions, "18") => Rule::UnnecessaryLiteralWithinDictCall,
+        (Flake8Comprehensions, "19") => Rule::UnnecessaryComprehensionAnyAll,
 
         // flake8-debugger
         (Flake8Debugger, "0") => Rule::Debugger,
@@ -507,6 +510,12 @@ pub fn code_to_rule(linter: Linter, code: &str) -> Option<Rule> {
         (Flake8Bandit, "506") => Rule::UnsafeYAMLLoad,
         (Flake8Bandit, "508") => Rule::SnmpInsecureVersion,
         (Flake8Bandit, "509") => Rule::SnmpWeakCryptography,
+        (Flake8Bandit, "602") => Rule::SubprocessPopenWithShellEqualsTrue,
+        (Flake8Bandit, "603") => Rule::SubprocessWithoutShellEqualsTrue,
+        (Flake8Bandit, "604") => Rule::CallWithShellEqualsTrue,
+        (Flake8Bandit, "605") => Rule::StartProcessWithAShell,
+        (Flake8Bandit, "606") => Rule::StartProcessWithNoShell,
+        (Flake8Bandit, "607") => Rule::StartProcessWithPartialPath,
         (Flake8Bandit, "608") => Rule::HardcodedSQLExpression,
         (Flake8Bandit, "612") => Rule::LoggingConfigInsecureListen,
         (Flake8Bandit, "701") => Rule::Jinja2AutoescapeFalse,
@@ -525,6 +534,8 @@ pub fn code_to_rule(linter: Linter, code: &str) -> Option<Rule> {
 
         // flake8-import-conventions
         (Flake8ImportConventions, "001") => Rule::UnconventionalImportAlias,
+        (Flake8ImportConventions, "002") => Rule::BannedImportAlias,
+        (Flake8ImportConventions, "003") => Rule::BannedImportFrom,
 
         // flake8-datetimez
         (Flake8Datetimez, "001") => Rule::CallDatetimeWithoutTzinfo,
@@ -573,6 +584,7 @@ pub fn code_to_rule(linter: Linter, code: &str) -> Option<Rule> {
         (Flake8Pyi, "012") => Rule::PassInClassBody,
         (Flake8Pyi, "014") => Rule::ArgumentDefaultInStub,
         (Flake8Pyi, "015") => Rule::AssignmentDefaultInStub,
+        (Flake8Pyi, "016") => Rule::DuplicateUnionMember,
         (Flake8Pyi, "021") => Rule::DocstringInStub,
         (Flake8Pyi, "033") => Rule::TypeCommentInStub,
 
@@ -608,7 +620,6 @@ pub fn code_to_rule(linter: Linter, code: &str) -> Option<Rule> {
         (Flake8Pie, "794") => Rule::DuplicateClassFieldDefinition,
         (Flake8Pie, "796") => Rule::NonUniqueEnums,
         (Flake8Pie, "800") => Rule::UnnecessarySpread,
-        (Flake8Pie, "802") => Rule::UnnecessaryComprehensionAnyAll,
         (Flake8Pie, "804") => Rule::UnnecessaryDictKwargs,
         (Flake8Pie, "807") => Rule::ReimplementedListBuiltin,
         (Flake8Pie, "810") => Rule::MultipleStartsEndsWith,
@@ -700,6 +711,8 @@ pub fn code_to_rule(linter: Linter, code: &str) -> Option<Rule> {
         (Ruff, "005") => Rule::CollectionLiteralConcatenation,
         (Ruff, "006") => Rule::AsyncioDanglingTask,
         (Ruff, "007") => Rule::PairwiseOverZipped,
+        (Ruff, "008") => Rule::MutableDataclassDefault,
+        (Ruff, "009") => Rule::FunctionCallInDataclassDefaultArgument,
         (Ruff, "100") => Rule::UnusedNOQA,
 
         // flake8-django

crates/ruff/src/directives.rs

@@ -9,7 +9,8 @@ use rustpython_parser::Tok;
 use crate::settings::Settings;
 
 bitflags! {
-    pub struct Flags: u32 {
+    #[derive(Debug, Copy, Clone)]
+    pub struct Flags: u8 {
         const NOQA = 0b0000_0001;
         const ISORT = 0b0000_0010;
     }

crates/ruff/src/docstrings/google.rs

@@ -26,6 +26,8 @@ pub(crate) static GOOGLE_SECTIONS: &[SectionKind] = &[
     SectionKind::KeywordArguments,
     SectionKind::Note,
     SectionKind::Notes,
+    SectionKind::OtherArgs,
+    SectionKind::OtherArguments,
     SectionKind::Return,
     SectionKind::Tip,
     SectionKind::Todo,

crates/ruff/src/docstrings/numpy.rs

@@ -14,6 +14,7 @@ pub(crate) static NUMPY_SECTIONS: &[SectionKind] = &[
     SectionKind::Yields,
     // NumPy-only
     SectionKind::ExtendedSummary,
+    SectionKind::OtherParams,
     SectionKind::OtherParameters,
     SectionKind::Parameters,
     SectionKind::ShortSummary,

crates/ruff/src/docstrings/sections.rs

@@ -22,6 +22,9 @@ pub enum SectionKind {
     Methods,
     Note,
     Notes,
+    OtherArgs,
+    OtherArguments,
+    OtherParams,
     OtherParameters,
     Parameters,
     Raises,
@@ -59,6 +62,9 @@ impl SectionKind {
             "methods" => Some(Self::Methods),
             "note" => Some(Self::Note),
             "notes" => Some(Self::Notes),
+            "other args" => Some(Self::OtherArgs),
+            "other arguments" => Some(Self::OtherArguments),
+            "other params" => Some(Self::OtherParams),
             "other parameters" => Some(Self::OtherParameters),
             "parameters" => Some(Self::Parameters),
             "raises" => Some(Self::Raises),
@@ -97,6 +103,9 @@ impl SectionKind {
             Self::Methods => "Methods",
             Self::Note => "Note",
             Self::Notes => "Notes",
+            Self::OtherArgs => "Other Args",
+            Self::OtherArguments => "Other Arguments",
+            Self::OtherParams => "Other Params",
             Self::OtherParameters => "Other Parameters",
             Self::Parameters => "Parameters",
             Self::Raises => "Raises",

crates/ruff/src/fs.rs

@@ -1,36 +1,21 @@
 use std::path::{Path, PathBuf};
 
-use anyhow::{anyhow, Result};
 use globset::GlobMatcher;
 use log::debug;
 use path_absolutize::{path_dedot, Absolutize};
 
 use crate::registry::RuleSet;
 
-/// Extract the absolute path and basename (as strings) from a Path.
-pub fn extract_path_names(path: &Path) -> Result<(&str, &str)> {
-    let file_path = path
-        .to_str()
-        .ok_or_else(|| anyhow!("Unable to parse filename: {:?}", path))?;
-    let file_basename = path
-        .file_name()
-        .ok_or_else(|| anyhow!("Unable to parse filename: {:?}", path))?
-        .to_str()
-        .ok_or_else(|| anyhow!("Unable to parse filename: {:?}", path))?;
-    Ok((file_path, file_basename))
-}
-
 /// Create a set with codes matching the pattern/code pairs.
 pub(crate) fn ignores_from_path(
     path: &Path,
     pattern_code_pairs: &[(GlobMatcher, GlobMatcher, RuleSet)],
 ) -> RuleSet {
-    let (file_path, file_basename) = extract_path_names(path).expect("Unable to parse filename");
-
+    let file_name = path.file_name().expect("Unable to parse filename");
     pattern_code_pairs
         .iter()
         .filter_map(|(absolute, basename, rules)| {
-            if basename.is_match(file_basename) {
+            if basename.is_match(file_name) {
                 debug!(
                     "Adding per-file ignores for {:?} due to basename match on {:?}: {:?}",
                     path,
@@ -38,7 +23,7 @@ pub(crate) fn ignores_from_path(
                     rules
                 );
                 Some(rules)
-            } else if absolute.is_match(file_path) {
+            } else if absolute.is_match(path) {
                 debug!(
                     "Adding per-file ignores for {:?} due to absolute match on {:?}: {:?}",
                     path,

crates/ruff/src/importer.rs

@@ -174,7 +174,7 @@ fn match_docstring_end(body: &[Stmt]) -> Option<Location> {
 /// along with a trailing newline suffix.
 fn end_of_statement_insertion(stmt: &Stmt, locator: &Locator, stylist: &Stylist) -> Insertion {
     let location = stmt.end_location.unwrap();
-    let mut tokens = lexer::lex_located(locator.skip(location), Mode::Module, location).flatten();
+    let mut tokens = lexer::lex_located(locator.after(location), Mode::Module, location).flatten();
     if let Some((.., Tok::Semi, end)) = tokens.next() {
         // If the first token after the docstring is a semicolon, insert after the semicolon as an
         // inline statement;
@@ -207,7 +207,7 @@ fn top_of_file_insertion(body: &[Stmt], locator: &Locator, stylist: &Stylist) ->
     let mut location = if let Some(location) = match_docstring_end(body) {
         // If the first token after the docstring is a semicolon, insert after the semicolon as an
         // inline statement;
-        let first_token = lexer::lex_located(locator.skip(location), Mode::Module, location)
+        let first_token = lexer::lex_located(locator.after(location), Mode::Module, location)
             .flatten()
             .next();
         if let Some((.., Tok::Semi, end)) = first_token {
@@ -222,7 +222,7 @@ fn top_of_file_insertion(body: &[Stmt], locator: &Locator, stylist: &Stylist) ->
 
     // Skip over any comments and empty lines.
     for (.., tok, end) in
-        lexer::lex_located(locator.skip(location), Mode::Module, location).flatten()
+        lexer::lex_located(locator.after(location), Mode::Module, location).flatten()
     {
         if matches!(tok, Tok::Comment(..) | Tok::Newline) {
             location = Location::new(end.row() + 1, 0);

crates/ruff/src/linter.rs

@@ -1,4 +1,5 @@
 use std::borrow::Cow;
+use std::ops::Deref;
 use std::path::Path;
 
 use anyhow::{anyhow, Result};
@@ -10,7 +11,7 @@ use rustpython_parser::ParseError;
 
 use ruff_diagnostics::Diagnostic;
 use ruff_python_ast::imports::ImportMap;
-use ruff_python_ast::source_code::{Indexer, Locator, Stylist};
+use ruff_python_ast::source_code::{Indexer, Locator, SourceFileBuilder, Stylist};
 use ruff_python_stdlib::path::is_python_stub_file;
 
 use crate::autofix::fix_file;
@@ -22,7 +23,7 @@ use crate::checkers::physical_lines::check_physical_lines;
 use crate::checkers::tokens::check_tokens;
 use crate::directives::Directives;
 use crate::doc_lines::{doc_lines_from_ast, doc_lines_from_tokens};
-use crate::message::{Message, Source};
+use crate::message::Message;
 use crate::noqa::add_noqa;
 use crate::registry::{AsRule, Rule};
 use crate::rules::pycodestyle;
@@ -196,13 +197,7 @@ pub fn check_path(
         .any(|rule_code| rule_code.lint_source().is_physical_lines())
     {
         diagnostics.extend(check_physical_lines(
-            path,
-            locator,
-            stylist,
-            indexer.commented_lines(),
-            &doc_lines,
-            settings,
-            autofix,
+            path, locator, stylist, indexer, &doc_lines, settings, autofix,
         ));
     }
 
@@ -359,28 +354,41 @@ pub fn lint_only(
         autofix,
     );
 
-    // Convert from diagnostics to messages.
-    let path_lossy = path.to_string_lossy();
-    result.map(|(messages, imports)| {
+    result.map(|(diagnostics, imports)| {
         (
-            messages
-                .into_iter()
-                .map(|diagnostic| {
-                    let source = if settings.show_source {
-                        Some(Source::from_diagnostic(&diagnostic, &locator))
-                    } else {
-                        None
-                    };
-                    let lineno = diagnostic.location.row();
-                    let noqa_row = *directives.noqa_line_for.get(&lineno).unwrap_or(&lineno);
-                    Message::from_diagnostic(diagnostic, path_lossy.to_string(), source, noqa_row)
-                })
-                .collect(),
+            diagnostics_to_messages(diagnostics, path, settings, &locator, &directives),
             imports,
         )
     })
 }
 
+/// Convert from diagnostics to messages.
+fn diagnostics_to_messages(
+    diagnostics: Vec<Diagnostic>,
+    path: &Path,
+    settings: &Settings,
+    locator: &Locator,
+    directives: &Directives,
+) -> Vec<Message> {
+    let file = once_cell::unsync::Lazy::new(|| {
+        let mut builder = SourceFileBuilder::new(&path.to_string_lossy());
+        if settings.show_source {
+            builder.set_source_code(&locator.to_source_code());
+        }
+
+        builder.finish()
+    });
+
+    diagnostics
+        .into_iter()
+        .map(|diagnostic| {
+            let lineno = diagnostic.location.row();
+            let noqa_row = *directives.noqa_line_for.get(&lineno).unwrap_or(&lineno);
+            Message::from_diagnostic(diagnostic, file.deref().clone(), noqa_row)
+        })
+        .collect()
+}
+
 /// Generate `Diagnostic`s from source code content, iteratively autofixing
 /// until stable.
 pub fn lint_fix<'a>(
@@ -502,30 +510,10 @@ This indicates a bug in `{}`. If you could open an issue at:
             }
         }
 
-        // Convert to messages.
-        let path_lossy = path.to_string_lossy();
         return Ok(FixerResult {
-            result: result.map(|(messages, imports)| {
+            result: result.map(|(diagnostics, imports)| {
                 (
-                    messages
-                        .into_iter()
-                        .map(|diagnostic| {
-                            let source = if settings.show_source {
-                                Some(Source::from_diagnostic(&diagnostic, &locator))
-                            } else {
-                                None
-                            };
-                            let lineno = diagnostic.location.row();
-                            let noqa_row =
-                                *directives.noqa_line_for.get(&lineno).unwrap_or(&lineno);
-                            Message::from_diagnostic(
-                                diagnostic,
-                                path_lossy.to_string(),
-                                source,
-                                noqa_row,
-                            )
-                        })
-                        .collect(),
+                    diagnostics_to_messages(diagnostics, path, settings, &locator, &directives),
                     imports,
                 )
             }),

crates/ruff/src/message.rs

@@ -1,89 +0,0 @@
-use std::cmp::Ordering;
-
-pub use rustpython_parser::ast::Location;
-use serde::{Deserialize, Serialize};
-
-use ruff_diagnostics::{Diagnostic, DiagnosticKind, Fix};
-use ruff_python_ast::source_code::Locator;
-use ruff_python_ast::types::Range;
-
-#[derive(Debug, PartialEq, Eq, Serialize, Deserialize)]
-pub struct Message {
-    pub kind: DiagnosticKind,
-    pub location: Location,
-    pub end_location: Location,
-    pub fix: Fix,
-    pub filename: String,
-    pub source: Option<Source>,
-    pub noqa_row: usize,
-}
-
-impl Message {
-    pub fn from_diagnostic(
-        diagnostic: Diagnostic,
-        filename: String,
-        source: Option<Source>,
-        noqa_row: usize,
-    ) -> Self {
-        Self {
-            kind: diagnostic.kind,
-            location: Location::new(diagnostic.location.row(), diagnostic.location.column() + 1),
-            end_location: Location::new(
-                diagnostic.end_location.row(),
-                diagnostic.end_location.column() + 1,
-            ),
-            fix: diagnostic.fix,
-            filename,
-            source,
-            noqa_row,
-        }
-    }
-}
-
-impl Ord for Message {
-    fn cmp(&self, other: &Self) -> Ordering {
-        (&self.filename, self.location.row(), self.location.column()).cmp(&(
-            &other.filename,
-            other.location.row(),
-            other.location.column(),
-        ))
-    }
-}
-
-impl PartialOrd for Message {
-    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
-        Some(self.cmp(other))
-    }
-}
-
-#[derive(Debug, PartialEq, Eq, Serialize, Deserialize)]
-pub struct Source {
-    pub contents: String,
-    pub range: (usize, usize),
-}
-
-impl Source {
-    pub fn from_diagnostic(diagnostic: &Diagnostic, locator: &Locator) -> Self {
-        let location = Location::new(diagnostic.location.row(), 0);
-        // Diagnostics can already extend one-past-the-end. If they do, though, then
-        // they'll end at the start of a line. We need to avoid extending by yet another
-        // line past-the-end.
-        let end_location = if diagnostic.end_location.column() == 0 {
-            diagnostic.end_location
-        } else {
-            Location::new(diagnostic.end_location.row() + 1, 0)
-        };
-        let source = locator.slice(Range::new(location, end_location));
-        let num_chars_in_range = locator
-            .slice(Range::new(diagnostic.location, diagnostic.end_location))
-            .chars()
-            .count();
-        Source {
-            contents: source.to_string(),
-            range: (
-                diagnostic.location.column(),
-                diagnostic.location.column() + num_chars_in_range,
-            ),
-        }
-    }
-}

crates/ruff/src/message/azure.rs

@@ -0,0 +1,53 @@
+use crate::message::{Emitter, EmitterContext, Message};
+use crate::registry::AsRule;
+use std::io::Write;
+
+/// Generate error logging commands for Azure Pipelines format.
+/// See [documentation](https://learn.microsoft.com/en-us/azure/devops/pipelines/scripts/logging-commands?view=azure-devops&tabs=bash#logissue-log-an-error-or-warning)
+#[derive(Default)]
+pub struct AzureEmitter;
+
+impl Emitter for AzureEmitter {
+    fn emit(
+        &mut self,
+        writer: &mut dyn Write,
+        messages: &[Message],
+        context: &EmitterContext,
+    ) -> anyhow::Result<()> {
+        for message in messages {
+            let (line, col) = if context.is_jupyter_notebook(message.filename()) {
+                // We can't give a reasonable location for the structured formats,
+                // so we show one that's clearly a fallback
+                (1, 0)
+            } else {
+                (message.location.row(), message.location.column())
+            };
+
+            writeln!(
+                writer,
+                "##vso[task.logissue type=error\
+                        ;sourcepath={filename};linenumber={line};columnnumber={col};code={code};]{body}",
+                filename = message.filename(),
+                code = message.kind.rule().noqa_code(),
+                body = message.kind.body,
+            )?;
+        }
+
+        Ok(())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::message::tests::{capture_emitter_output, create_messages};
+    use crate::message::AzureEmitter;
+    use insta::assert_snapshot;
+
+    #[test]
+    fn output() {
+        let mut emitter = AzureEmitter::default();
+        let content = capture_emitter_output(&mut emitter, &create_messages());
+
+        assert_snapshot!(content);
+    }
+}

crates/ruff/src/message/diff.rs

@@ -0,0 +1,194 @@
+use crate::message::Message;
+use colored::{Color, ColoredString, Colorize, Styles};
+use ruff_diagnostics::Fix;
+use ruff_python_ast::source_code::{OneIndexed, SourceCode};
+use ruff_python_ast::types::Range;
+use ruff_text_size::{TextRange, TextSize};
+use similar::{ChangeTag, TextDiff};
+use std::fmt::{Display, Formatter};
+use std::num::NonZeroUsize;
+
+/// Renders a diff that shows the code fixes.
+///
+/// The implementation isn't fully fledged out and only used by tests. Before using in production, try
+/// * Improve layout
+/// * Replace tabs with spaces for a consistent experience across terminals
+/// * Replace zero-width whitespaces
+/// * Print a simpler diff if only a single line has changed
+/// * Compute the diff from the [`Edit`] because diff calculation is expensive.
+pub(super) struct Diff<'a> {
+    fix: &'a Fix,
+    source_code: SourceCode<'a, 'a>,
+}
+
+impl<'a> Diff<'a> {
+    pub fn from_message(message: &'a Message) -> Option<Diff> {
+        match message.file.source_code() {
+            Some(source_code) if !message.fix.is_empty() => Some(Diff {
+                source_code,
+                fix: &message.fix,
+            }),
+            _ => None,
+        }
+    }
+}
+
+impl Display for Diff<'_> {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        let mut output = String::with_capacity(self.source_code.text().len());
+        let mut last_end = TextSize::default();
+
+        for edit in self.fix.edits() {
+            let edit_range = self
+                .source_code
+                .text_range(Range::new(edit.location(), edit.end_location()));
+            output.push_str(&self.source_code.text()[TextRange::new(last_end, edit_range.start())]);
+            output.push_str(edit.content().unwrap_or_default());
+            last_end = edit_range.end();
+        }
+
+        output.push_str(&self.source_code.text()[usize::from(last_end)..]);
+
+        let diff = TextDiff::from_lines(self.source_code.text(), &output);
+
+        writeln!(f, "{}", "ℹ Suggested fix".blue())?;
+
+        let (largest_old, largest_new) = diff
+            .ops()
+            .last()
+            .map(|op| (op.old_range().start, op.new_range().start))
+            .unwrap_or_default();
+
+        let digit_with =
+            calculate_print_width(OneIndexed::from_zero_indexed(largest_new.max(largest_old)));
+
+        for (idx, group) in diff.grouped_ops(3).iter().enumerate() {
+            if idx > 0 {
+                writeln!(f, "{:-^1$}", "-", 80)?;
+            }
+            for op in group {
+                for change in diff.iter_inline_changes(op) {
+                    let sign = match change.tag() {
+                        ChangeTag::Delete => "-",
+                        ChangeTag::Insert => "+",
+                        ChangeTag::Equal => " ",
+                    };
+
+                    let line_style = LineStyle::from(change.tag());
+
+                    let old_index = change.old_index().map(OneIndexed::from_zero_indexed);
+                    let new_index = change.new_index().map(OneIndexed::from_zero_indexed);
+
+                    write!(
+                        f,
+                        "{} {} |{}",
+                        Line {
+                            index: old_index,
+                            width: digit_with
+                        },
+                        Line {
+                            index: new_index,
+                            width: digit_with
+                        },
+                        line_style.apply_to(sign).bold()
+                    )?;
+
+                    for (emphasized, value) in change.iter_strings_lossy() {
+                        if emphasized {
+                            write!(f, "{}", line_style.apply_to(&value).underline().on_black())?;
+                        } else {
+                            write!(f, "{}", line_style.apply_to(&value))?;
+                        }
+                    }
+                    if change.missing_newline() {
+                        writeln!(f)?;
+                    }
+                }
+            }
+        }
+
+        Ok(())
+    }
+}
+
+struct LineStyle {
+    fgcolor: Option<Color>,
+    style: Option<Styles>,
+}
+
+impl LineStyle {
+    fn apply_to(&self, input: &str) -> ColoredString {
+        let mut colored = ColoredString::from(input);
+        if let Some(color) = self.fgcolor {
+            colored = colored.color(color);
+        }
+
+        if let Some(style) = self.style {
+            match style {
+                Styles::Clear => colored.clear(),
+                Styles::Bold => colored.bold(),
+                Styles::Dimmed => colored.dimmed(),
+                Styles::Underline => colored.underline(),
+                Styles::Reversed => colored.reversed(),
+                Styles::Italic => colored.italic(),
+                Styles::Blink => colored.blink(),
+                Styles::Hidden => colored.hidden(),
+                Styles::Strikethrough => colored.strikethrough(),
+            }
+        } else {
+            colored
+        }
+    }
+}
+
+impl From<ChangeTag> for LineStyle {
+    fn from(value: ChangeTag) -> Self {
+        match value {
+            ChangeTag::Equal => LineStyle {
+                fgcolor: None,
+                style: Some(Styles::Dimmed),
+            },
+            ChangeTag::Delete => LineStyle {
+                fgcolor: Some(Color::Red),
+                style: None,
+            },
+            ChangeTag::Insert => LineStyle {
+                fgcolor: Some(Color::Green),
+                style: None,
+            },
+        }
+    }
+}
+
+struct Line {
+    index: Option<OneIndexed>,
+    width: NonZeroUsize,
+}
+
+impl Display for Line {
+    fn fmt(&self, f: &mut Formatter) -> std::fmt::Result {
+        match self.index {
+            None => {
+                for _ in 0..self.width.get() {
+                    f.write_str(" ")?;
+                }
+                Ok(())
+            }
+            Some(idx) => write!(f, "{:<width$}", idx, width = self.width.get()),
+        }
+    }
+}
+
+/// Calculate the length of the string representation of `value`
+pub(super) fn calculate_print_width(mut value: OneIndexed) -> NonZeroUsize {
+    const TEN: OneIndexed = OneIndexed::from_zero_indexed(9);
+
+    let mut width = OneIndexed::ONE;
+
+    while value >= TEN {
+        value = OneIndexed::new(value.get() / 10).unwrap_or(OneIndexed::MIN);
+        width = width.checked_add(1).unwrap();
+    }
+
+    width
+}

crates/ruff/src/message/github.rs

@@ -0,0 +1,65 @@
+use crate::fs::relativize_path;
+use crate::message::{Emitter, EmitterContext, Message};
+use crate::registry::AsRule;
+use std::io::Write;
+
+/// Generate error workflow command in GitHub Actions format.
+/// See: [GitHub documentation](https://docs.github.com/en/actions/reference/workflow-commands-for-github-actions#setting-an-error-message)
+#[derive(Default)]
+pub struct GithubEmitter;
+
+impl Emitter for GithubEmitter {
+    fn emit(
+        &mut self,
+        writer: &mut dyn Write,
+        messages: &[Message],
+        context: &EmitterContext,
+    ) -> anyhow::Result<()> {
+        for message in messages {
+            let (row, column) = if context.is_jupyter_notebook(message.filename()) {
+                // We can't give a reasonable location for the structured formats,
+                // so we show one that's clearly a fallback
+                (1, 0)
+            } else {
+                (message.location.row(), message.location.column())
+            };
+
+            write!(
+                writer,
+                "::error title=Ruff \
+                         ({code}),file={file},line={row},col={column},endLine={end_row},endColumn={end_column}::",
+                code = message.kind.rule().noqa_code(),
+                file = message.filename(),
+                row = message.location.row(),
+                column = message.location.column(),
+                end_row = message.end_location.row(),
+                end_column = message.end_location.column(),
+            )?;
+
+            writeln!(
+                writer,
+                "{path}:{row}:{column}: {code} {body}",
+                path = relativize_path(message.filename()),
+                code = message.kind.rule().noqa_code(),
+                body = message.kind.body,
+            )?;
+        }
+
+        Ok(())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::message::tests::{capture_emitter_output, create_messages};
+    use crate::message::GithubEmitter;
+    use insta::assert_snapshot;
+
+    #[test]
+    fn output() {
+        let mut emitter = GithubEmitter::default();
+        let content = capture_emitter_output(&mut emitter, &create_messages());
+
+        assert_snapshot!(content);
+    }
+}

crates/ruff/src/message/gitlab.rs

@@ -0,0 +1,153 @@
+use crate::fs::{relativize_path, relativize_path_to};
+use crate::message::{Emitter, EmitterContext, Message};
+use crate::registry::AsRule;
+use serde::ser::SerializeSeq;
+use serde::{Serialize, Serializer};
+use serde_json::json;
+use std::collections::hash_map::DefaultHasher;
+use std::hash::{Hash, Hasher};
+use std::io::Write;
+
+/// Generate JSON with violations in GitLab CI format
+//  https://docs.gitlab.com/ee/ci/testing/code_quality.html#implement-a-custom-tool
+pub struct GitlabEmitter {
+    project_dir: Option<String>,
+}
+
+impl Default for GitlabEmitter {
+    fn default() -> Self {
+        Self {
+            project_dir: std::env::var("CI_PROJECT_DIR").ok(),
+        }
+    }
+}
+
+impl Emitter for GitlabEmitter {
+    fn emit(
+        &mut self,
+        writer: &mut dyn Write,
+        messages: &[Message],
+        context: &EmitterContext,
+    ) -> anyhow::Result<()> {
+        serde_json::to_writer_pretty(
+            writer,
+            &SerializedMessages {
+                messages,
+                context,
+                project_dir: self.project_dir.as_deref(),
+            },
+        )?;
+
+        Ok(())
+    }
+}
+
+struct SerializedMessages<'a> {
+    messages: &'a [Message],
+    context: &'a EmitterContext<'a>,
+    project_dir: Option<&'a str>,
+}
+
+impl Serialize for SerializedMessages<'_> {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        let mut s = serializer.serialize_seq(Some(self.messages.len()))?;
+
+        for message in self.messages {
+            let lines = if self.context.is_jupyter_notebook(message.filename()) {
+                // We can't give a reasonable location for the structured formats,
+                // so we show one that's clearly a fallback
+                json!({
+                    "begin": 1,
+                    "end": 1
+                })
+            } else {
+                json!({
+                    "begin": message.location.row(),
+                    "end": message.end_location.row()
+                })
+            };
+
+            let path = self.project_dir.as_ref().map_or_else(
+                || relativize_path(message.filename()),
+                |project_dir| relativize_path_to(message.filename(), project_dir),
+            );
+
+            let value = json!({
+                "description": format!("({}) {}", message.kind.rule().noqa_code(), message.kind.body),
+                "severity": "major",
+                "fingerprint": fingerprint(message),
+                "location": {
+                    "path": path,
+                    "lines": lines
+                }
+            });
+
+            s.serialize_element(&value)?;
+        }
+
+        s.end()
+    }
+}
+
+/// Generate a unique fingerprint to identify a violation.
+fn fingerprint(message: &Message) -> String {
+    let Message {
+        kind,
+        location,
+        end_location,
+        fix: _fix,
+        file,
+        noqa_row: _noqa_row,
+    } = message;
+
+    let mut hasher = DefaultHasher::new();
+
+    kind.rule().hash(&mut hasher);
+    location.row().hash(&mut hasher);
+    location.column().hash(&mut hasher);
+    end_location.row().hash(&mut hasher);
+    end_location.column().hash(&mut hasher);
+    file.name().hash(&mut hasher);
+
+    format!("{:x}", hasher.finish())
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::message::tests::{capture_emitter_output, create_messages};
+    use crate::message::GitlabEmitter;
+    use insta::assert_snapshot;
+
+    #[test]
+    fn output() {
+        let mut emitter = GitlabEmitter::default();
+        let content = capture_emitter_output(&mut emitter, &create_messages());
+
+        assert_snapshot!(redact_fingerprint(&content));
+    }
+
+    // Redact the fingerprint because the default hasher isn't stable across platforms.
+    fn redact_fingerprint(content: &str) -> String {
+        static FINGERPRINT_HAY_KEY: &str = r#""fingerprint": ""#;
+
+        let mut output = String::with_capacity(content.len());
+        let mut last = 0;
+
+        for (start, _) in content.match_indices(FINGERPRINT_HAY_KEY) {
+            let fingerprint_hash_start = start + FINGERPRINT_HAY_KEY.len();
+            output.push_str(&content[last..fingerprint_hash_start]);
+            output.push_str("<redacted>");
+            last = fingerprint_hash_start
+                + content[fingerprint_hash_start..]
+                    .find('"')
+                    .expect("Expected terminating quote");
+        }
+
+        output.push_str(&content[last..]);
+
+        output
+    }
+}

crates/ruff/src/message/grouped.rs

@@ -0,0 +1,190 @@
+use crate::fs::relativize_path;
+use crate::jupyter::JupyterIndex;
+use crate::message::text::{MessageCodeFrame, RuleCodeAndBody};
+use crate::message::{group_messages_by_filename, Emitter, EmitterContext, Message};
+use colored::Colorize;
+use std::fmt::{Display, Formatter};
+use std::io::Write;
+
+#[derive(Default)]
+pub struct GroupedEmitter {
+    show_fix_status: bool,
+}
+
+impl GroupedEmitter {
+    #[must_use]
+    pub fn with_show_fix_status(mut self, show_fix_status: bool) -> Self {
+        self.show_fix_status = show_fix_status;
+        self
+    }
+}
+
+impl Emitter for GroupedEmitter {
+    fn emit(
+        &mut self,
+        writer: &mut dyn Write,
+        messages: &[Message],
+        context: &EmitterContext,
+    ) -> anyhow::Result<()> {
+        for (filename, messages) in group_messages_by_filename(messages) {
+            // Compute the maximum number of digits in the row and column, for messages in
+            // this file.
+            let row_length = num_digits(
+                messages
+                    .iter()
+                    .map(|message| message.location.row())
+                    .max()
+                    .unwrap(),
+            );
+            let column_length = num_digits(
+                messages
+                    .iter()
+                    .map(|message| message.location.column())
+                    .max()
+                    .unwrap(),
+            );
+
+            // Print the filename.
+            writeln!(writer, "{}:", relativize_path(filename).underline())?;
+
+            // Print each message.
+            for message in messages {
+                write!(
+                    writer,
+                    "{}",
+                    DisplayGroupedMessage {
+                        message,
+                        show_fix_status: self.show_fix_status,
+                        row_length,
+                        column_length,
+                        jupyter_index: context.jupyter_index(message.filename()),
+                    }
+                )?;
+            }
+            writeln!(writer)?;
+        }
+
+        Ok(())
+    }
+}
+
+struct DisplayGroupedMessage<'a> {
+    message: &'a Message,
+    show_fix_status: bool,
+    row_length: usize,
+    column_length: usize,
+    jupyter_index: Option<&'a JupyterIndex>,
+}
+
+impl Display for DisplayGroupedMessage<'_> {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        let message = self.message;
+
+        write!(
+            f,
+            "  {row_padding}",
+            row_padding = " ".repeat(self.row_length - num_digits(message.location.row()))
+        )?;
+
+        // Check if we're working on a jupyter notebook and translate positions with cell accordingly
+        let (row, col) = if let Some(jupyter_index) = self.jupyter_index {
+            write!(
+                f,
+                "cell {cell}{sep}",
+                cell = jupyter_index.row_to_cell[message.location.row()],
+                sep = ":".cyan()
+            )?;
+            (
+                jupyter_index.row_to_row_in_cell[message.location.row()] as usize,
+                message.location.column(),
+            )
+        } else {
+            (message.location.row(), message.location.column())
+        };
+
+        writeln!(
+            f,
+            "{row}{sep}{col}{col_padding} {code_and_body}",
+            sep = ":".cyan(),
+            col_padding = " ".repeat(self.column_length - num_digits(message.location.column())),
+            code_and_body = RuleCodeAndBody {
+                message_kind: &message.kind,
+                show_fix_status: self.show_fix_status
+            },
+        )?;
+
+        {
+            use std::fmt::Write;
+            let mut padded = PadAdapter::new(f);
+            write!(padded, "{}", MessageCodeFrame { message })?;
+        }
+
+        writeln!(f)?;
+
+        Ok(())
+    }
+}
+
+fn num_digits(n: usize) -> usize {
+    std::iter::successors(Some(n), |n| {
+        let next = n / 10;
+
+        (next > 0).then_some(next)
+    })
+    .count()
+    .max(1)
+}
+
+/// Adapter that adds a '  ' at the start of every line without the need to copy the string.
+/// Inspired by Rust's `debug_struct()` internal implementation that also uses a `PadAdapter`.
+struct PadAdapter<'buf> {
+    buf: &'buf mut (dyn std::fmt::Write + 'buf),
+    on_newline: bool,
+}
+
+impl<'buf> PadAdapter<'buf> {
+    fn new(buf: &'buf mut (dyn std::fmt::Write + 'buf)) -> Self {
+        Self {
+            buf,
+            on_newline: true,
+        }
+    }
+}
+
+impl std::fmt::Write for PadAdapter<'_> {
+    fn write_str(&mut self, s: &str) -> std::fmt::Result {
+        for s in s.split_inclusive('\n') {
+            if self.on_newline {
+                self.buf.write_str("  ")?;
+            }
+
+            self.on_newline = s.ends_with('\n');
+            self.buf.write_str(s)?;
+        }
+
+        Ok(())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::message::tests::{capture_emitter_output, create_messages};
+    use crate::message::GroupedEmitter;
+    use insta::assert_snapshot;
+
+    #[test]
+    fn default() {
+        let mut emitter = GroupedEmitter::default();
+        let content = capture_emitter_output(&mut emitter, &create_messages());
+
+        assert_snapshot!(content);
+    }
+
+    #[test]
+    fn fix_status() {
+        let mut emitter = GroupedEmitter::default().with_show_fix_status(true);
+        let content = capture_emitter_output(&mut emitter, &create_messages());
+
+        assert_snapshot!(content);
+    }
+}

crates/ruff/src/message/json.rs

@@ -0,0 +1,101 @@
+use crate::message::{Emitter, EmitterContext, Message};
+use crate::registry::AsRule;
+use ruff_diagnostics::Edit;
+use serde::ser::SerializeSeq;
+use serde::{Serialize, Serializer};
+use serde_json::json;
+use std::io::Write;
+
+#[derive(Default)]
+pub struct JsonEmitter;
+
+impl Emitter for JsonEmitter {
+    fn emit(
+        &mut self,
+        writer: &mut dyn Write,
+        messages: &[Message],
+        _context: &EmitterContext,
+    ) -> anyhow::Result<()> {
+        serde_json::to_writer_pretty(writer, &ExpandedMessages { messages })?;
+
+        Ok(())
+    }
+}
+
+struct ExpandedMessages<'a> {
+    messages: &'a [Message],
+}
+
+impl Serialize for ExpandedMessages<'_> {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        let mut s = serializer.serialize_seq(Some(self.messages.len()))?;
+
+        for message in self.messages {
+            let fix = if message.fix.is_empty() {
+                None
+            } else {
+                Some(json!({
+                    "message": message.kind.suggestion.as_deref(),
+                    "edits": &ExpandedEdits { edits: message.fix.edits() },
+                }))
+            };
+
+            let value = json!({
+                "code": message.kind.rule().noqa_code().to_string(),
+                "message": message.kind.body,
+                "fix": fix,
+                "location": message.location,
+                "end_location": message.end_location,
+                "filename": message.filename(),
+                "noqa_row": message.noqa_row
+            });
+
+            s.serialize_element(&value)?;
+        }
+
+        s.end()
+    }
+}
+
+struct ExpandedEdits<'a> {
+    edits: &'a [Edit],
+}
+
+impl Serialize for ExpandedEdits<'_> {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        let mut s = serializer.serialize_seq(Some(self.edits.len()))?;
+
+        for edit in self.edits {
+            let value = json!({
+                "content": edit.content().unwrap_or_default(),
+                "location": edit.location(),
+                "end_location": edit.end_location()
+            });
+
+            s.serialize_element(&value)?;
+        }
+
+        s.end()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::message::tests::{capture_emitter_output, create_messages};
+    use crate::message::JsonEmitter;
+    use insta::assert_snapshot;
+
+    #[test]
+    fn output() {
+        let mut emitter = JsonEmitter::default();
+        let content = capture_emitter_output(&mut emitter, &create_messages());
+
+        assert_snapshot!(content);
+    }
+}

crates/ruff/src/message/junit.rs

@@ -0,0 +1,74 @@
+use crate::message::{group_messages_by_filename, Emitter, EmitterContext, Message};
+use crate::registry::AsRule;
+use quick_junit::{NonSuccessKind, Report, TestCase, TestCaseStatus, TestSuite};
+use std::io::Write;
+use std::path::Path;
+
+#[derive(Default)]
+pub struct JunitEmitter;
+
+impl Emitter for JunitEmitter {
+    fn emit(
+        &mut self,
+        writer: &mut dyn Write,
+        messages: &[Message],
+        context: &EmitterContext,
+    ) -> anyhow::Result<()> {
+        let mut report = Report::new("ruff");
+
+        for (filename, messages) in group_messages_by_filename(messages) {
+            let mut test_suite = TestSuite::new(filename);
+            test_suite
+                .extra
+                .insert("package".to_string(), "org.ruff".to_string());
+
+            for message in messages {
+                let mut status = TestCaseStatus::non_success(NonSuccessKind::Failure);
+                status.set_message(message.kind.body.clone());
+                let (row, col) = if context.is_jupyter_notebook(message.filename()) {
+                    // We can't give a reasonable location for the structured formats,
+                    // so we show one that's clearly a fallback
+                    (1, 0)
+                } else {
+                    (message.location.row(), message.location.column())
+                };
+
+                status.set_description(format!("line {row}, col {col}, {}", message.kind.body));
+                let mut case = TestCase::new(
+                    format!("org.ruff.{}", message.kind.rule().noqa_code()),
+                    status,
+                );
+                let file_path = Path::new(filename);
+                let file_stem = file_path.file_stem().unwrap().to_str().unwrap();
+                let classname = file_path.parent().unwrap().join(file_stem);
+                case.set_classname(classname.to_str().unwrap());
+                case.extra
+                    .insert("line".to_string(), message.location.row().to_string());
+                case.extra
+                    .insert("column".to_string(), message.location.column().to_string());
+
+                test_suite.add_test_case(case);
+            }
+            report.add_test_suite(test_suite);
+        }
+
+        report.serialize(writer)?;
+
+        Ok(())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::message::tests::{capture_emitter_output, create_messages};
+    use crate::message::JunitEmitter;
+    use insta::assert_snapshot;
+
+    #[test]
+    fn output() {
+        let mut emitter = JunitEmitter::default();
+        let content = capture_emitter_output(&mut emitter, &create_messages());
+
+        assert_snapshot!(content);
+    }
+}

crates/ruff/src/message/mod.rs

@@ -0,0 +1,198 @@
+mod azure;
+mod diff;
+mod github;
+mod gitlab;
+mod grouped;
+mod json;
+mod junit;
+mod pylint;
+mod text;
+
+use rustc_hash::FxHashMap;
+use std::cmp::Ordering;
+use std::collections::BTreeMap;
+use std::io::Write;
+
+pub use azure::AzureEmitter;
+pub use github::GithubEmitter;
+pub use gitlab::GitlabEmitter;
+pub use grouped::GroupedEmitter;
+pub use json::JsonEmitter;
+pub use junit::JunitEmitter;
+pub use pylint::PylintEmitter;
+pub use rustpython_parser::ast::Location;
+pub use text::TextEmitter;
+
+use crate::jupyter::JupyterIndex;
+use ruff_diagnostics::{Diagnostic, DiagnosticKind, Fix};
+use ruff_python_ast::source_code::SourceFile;
+
+#[derive(Debug, PartialEq, Eq)]
+pub struct Message {
+    pub kind: DiagnosticKind,
+    pub location: Location,
+    pub end_location: Location,
+    pub fix: Fix,
+    pub file: SourceFile,
+    pub noqa_row: usize,
+}
+
+impl Message {
+    pub fn from_diagnostic(diagnostic: Diagnostic, file: SourceFile, noqa_row: usize) -> Self {
+        Self {
+            kind: diagnostic.kind,
+            location: Location::new(diagnostic.location.row(), diagnostic.location.column() + 1),
+            end_location: Location::new(
+                diagnostic.end_location.row(),
+                diagnostic.end_location.column() + 1,
+            ),
+            fix: diagnostic.fix,
+            file,
+            noqa_row,
+        }
+    }
+
+    pub fn filename(&self) -> &str {
+        self.file.name()
+    }
+}
+
+impl Ord for Message {
+    fn cmp(&self, other: &Self) -> Ordering {
+        (self.filename(), self.location.row(), self.location.column()).cmp(&(
+            other.filename(),
+            other.location.row(),
+            other.location.column(),
+        ))
+    }
+}
+
+impl PartialOrd for Message {
+    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+        Some(self.cmp(other))
+    }
+}
+
+fn group_messages_by_filename(messages: &[Message]) -> BTreeMap<&str, Vec<&Message>> {
+    let mut grouped_messages = BTreeMap::default();
+    for message in messages {
+        grouped_messages
+            .entry(message.filename())
+            .or_insert_with(Vec::new)
+            .push(message);
+    }
+    grouped_messages
+}
+
+/// Display format for a [`Message`]s.
+///
+/// The emitter serializes a slice of [`Message`]'s and writes them to a [`Write`].
+pub trait Emitter {
+    /// Serializes the `messages` and writes the output to `writer`.
+    fn emit(
+        &mut self,
+        writer: &mut dyn Write,
+        messages: &[Message],
+        context: &EmitterContext,
+    ) -> anyhow::Result<()>;
+}
+
+/// Context passed to [`Emitter`].
+pub struct EmitterContext<'a> {
+    jupyter_indices: &'a FxHashMap<String, JupyterIndex>,
+}
+
+impl<'a> EmitterContext<'a> {
+    pub fn new(jupyter_indices: &'a FxHashMap<String, JupyterIndex>) -> Self {
+        Self { jupyter_indices }
+    }
+
+    /// Tests if the file with `name` is a jupyter notebook.
+    pub fn is_jupyter_notebook(&self, name: &str) -> bool {
+        self.jupyter_indices.contains_key(name)
+    }
+
+    /// Returns the file's [`JupyterIndex`] if the file `name` is a jupyter notebook.
+    pub fn jupyter_index(&self, name: &str) -> Option<&JupyterIndex> {
+        self.jupyter_indices.get(name)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::message::{Emitter, EmitterContext, Location, Message};
+    use crate::rules::pyflakes::rules::{UndefinedName, UnusedImport, UnusedVariable};
+    use ruff_diagnostics::{Diagnostic, Edit, Fix};
+    use ruff_python_ast::source_code::SourceFileBuilder;
+    use ruff_python_ast::types::Range;
+    use rustc_hash::FxHashMap;
+
+    pub(super) fn create_messages() -> Vec<Message> {
+        let fib = r#"import os
+
+
+def fibonacci(n):
+    """Compute the nth number in the Fibonacci sequence."""
+    x = 1
+    if n == 0:
+        return 0
+    elif n == 1:
+        return 1
+    else:
+        return fibonacci(n - 1) + fibonacci(n - 2)
+"#;
+
+        let unused_import = Diagnostic::new(
+            UnusedImport {
+                name: "os".to_string(),
+                context: None,
+                multiple: false,
+            },
+            Range::new(Location::new(1, 7), Location::new(1, 9)),
+        );
+
+        let fib_source = SourceFileBuilder::new("fib.py").source_text(fib).finish();
+
+        let unused_variable = Diagnostic::new(
+            UnusedVariable {
+                name: "x".to_string(),
+            },
+            Range::new(Location::new(6, 4), Location::new(6, 5)),
+        )
+        .with_fix(Fix::new(vec![Edit::deletion(
+            Location::new(6, 4),
+            Location::new(6, 9),
+        )]));
+
+        let file_2 = r#"if a == 1: pass"#;
+
+        let undefined_name = Diagnostic::new(
+            UndefinedName {
+                name: "a".to_string(),
+            },
+            Range::new(Location::new(1, 3), Location::new(1, 4)),
+        );
+
+        let file_2_source = SourceFileBuilder::new("undef.py")
+            .source_text(file_2)
+            .finish();
+
+        vec![
+            Message::from_diagnostic(unused_import, fib_source.clone(), 1),
+            Message::from_diagnostic(unused_variable, fib_source, 1),
+            Message::from_diagnostic(undefined_name, file_2_source, 1),
+        ]
+    }
+
+    pub(super) fn capture_emitter_output(
+        emitter: &mut dyn Emitter,
+        messages: &[Message],
+    ) -> String {
+        let indices = FxHashMap::default();
+        let context = EmitterContext::new(&indices);
+        let mut output: Vec<u8> = Vec::new();
+        emitter.emit(&mut output, messages, &context).unwrap();
+
+        String::from_utf8(output).expect("Output to be valid UTF-8")
+    }
+}

crates/ruff/src/message/pylint.rs

@@ -0,0 +1,53 @@
+use crate::fs::relativize_path;
+use crate::message::{Emitter, EmitterContext, Message};
+use crate::registry::AsRule;
+use std::io::Write;
+
+/// Generate violations in Pylint format.
+/// See: [Flake8 documentation](https://flake8.pycqa.org/en/latest/internal/formatters.html#pylint-formatter)
+#[derive(Default)]
+pub struct PylintEmitter;
+
+impl Emitter for PylintEmitter {
+    fn emit(
+        &mut self,
+        writer: &mut dyn Write,
+        messages: &[Message],
+        context: &EmitterContext,
+    ) -> anyhow::Result<()> {
+        for message in messages {
+            let row = if context.is_jupyter_notebook(message.filename()) {
+                // We can't give a reasonable location for the structured formats,
+                // so we show one that's clearly a fallback
+                1
+            } else {
+                message.location.row()
+            };
+
+            writeln!(
+                writer,
+                "{path}:{row}: [{code}] {body}",
+                path = relativize_path(message.filename()),
+                code = message.kind.rule().noqa_code(),
+                body = message.kind.body,
+            )?;
+        }
+
+        Ok(())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::message::tests::{capture_emitter_output, create_messages};
+    use crate::message::PylintEmitter;
+    use insta::assert_snapshot;
+
+    #[test]
+    fn output() {
+        let mut emitter = PylintEmitter::default();
+        let content = capture_emitter_output(&mut emitter, &create_messages());
+
+        assert_snapshot!(content);
+    }
+}

crates/ruff/src/message/snapshots/ruff__message__azure__tests__output.snap

@@ -0,0 +1,8 @@
+---
+source: crates/ruff/src/message/azure.rs
+expression: content
+---
+##vso[task.logissue type=error;sourcepath=fib.py;linenumber=1;columnnumber=8;code=F401;]`os` imported but unused
+##vso[task.logissue type=error;sourcepath=fib.py;linenumber=6;columnnumber=5;code=F841;]Local variable `x` is assigned to but never used
+##vso[task.logissue type=error;sourcepath=undef.py;linenumber=1;columnnumber=4;code=F821;]Undefined name `a`
+

crates/ruff/src/message/snapshots/ruff__message__github__tests__output.snap

@@ -0,0 +1,8 @@
+---
+source: crates/ruff/src/message/github.rs
+expression: content
+---
+::error title=Ruff (F401),file=fib.py,line=1,col=8,endLine=1,endColumn=10::fib.py:1:8: F401 `os` imported but unused
+::error title=Ruff (F841),file=fib.py,line=6,col=5,endLine=6,endColumn=6::fib.py:6:5: F841 Local variable `x` is assigned to but never used
+::error title=Ruff (F821),file=undef.py,line=1,col=4,endLine=1,endColumn=5::undef.py:1:4: F821 Undefined name `a`
+

crates/ruff/src/message/snapshots/ruff__message__gitlab__tests__output.snap

@@ -0,0 +1,42 @@
+---
+source: crates/ruff/src/message/gitlab.rs
+expression: redact_fingerprint(&content)
+---
+[
+  {
+    "description": "(F401) `os` imported but unused",
+    "severity": "major",
+    "fingerprint": "<redacted>",
+    "location": {
+      "path": "fib.py",
+      "lines": {
+        "begin": 1,
+        "end": 1
+      }
+    }
+  },
+  {
+    "description": "(F841) Local variable `x` is assigned to but never used",
+    "severity": "major",
+    "fingerprint": "<redacted>",
+    "location": {
+      "path": "fib.py",
+      "lines": {
+        "begin": 6,
+        "end": 6
+      }
+    }
+  },
+  {
+    "description": "(F821) Undefined name `a`",
+    "severity": "major",
+    "fingerprint": "<redacted>",
+    "location": {
+      "path": "undef.py",
+      "lines": {
+        "begin": 1,
+        "end": 1
+      }
+    }
+  }
+]

crates/ruff/src/message/snapshots/ruff__message__grouped__tests__default.snap

@@ -0,0 +1,33 @@
+---
+source: crates/ruff/src/message/grouped.rs
+expression: content
+---
+fib.py:
+  1:8 F401 `os` imported but unused
+    |
+  1 | import os
+    |        ^^ F401
+    |
+    = help: Remove unused import: `os`
+
+  6:5 F841 Local variable `x` is assigned to but never used
+     |
+   6 | def fibonacci(n):
+   7 |     """Compute the nth number in the Fibonacci sequence."""
+   8 |     x = 1
+     |     ^ F841
+   9 |     if n == 0:
+  10 |         return 0
+     |
+     = help: Remove assignment to unused variable `x`
+
+
+undef.py:
+  1:4 F821 Undefined name `a`
+    |
+  1 | if a == 1: pass
+    |    ^ F821
+    |
+
+
+

crates/ruff/src/message/snapshots/ruff__message__grouped__tests__fix_status.snap

@@ -0,0 +1,33 @@
+---
+source: crates/ruff/src/message/grouped.rs
+expression: content
+---
+fib.py:
+  1:8 F401 [*] `os` imported but unused
+    |
+  1 | import os
+    |        ^^ F401
+    |
+    = help: Remove unused import: `os`
+
+  6:5 F841 [*] Local variable `x` is assigned to but never used
+     |
+   6 | def fibonacci(n):
+   7 |     """Compute the nth number in the Fibonacci sequence."""
+   8 |     x = 1
+     |     ^ F841
+   9 |     if n == 0:
+  10 |         return 0
+     |
+     = help: Remove assignment to unused variable `x`
+
+
+undef.py:
+  1:4 F821 Undefined name `a`
+    |
+  1 | if a == 1: pass
+    |    ^ F821
+    |
+
+
+

crates/ruff/src/message/snapshots/ruff__message__json__tests__output.snap

@@ -0,0 +1,66 @@
+---
+source: crates/ruff/src/message/json.rs
+expression: content
+---
+[
+  {
+    "code": "F401",
+    "message": "`os` imported but unused",
+    "fix": null,
+    "location": {
+      "row": 1,
+      "column": 8
+    },
+    "end_location": {
+      "row": 1,
+      "column": 10
+    },
+    "filename": "fib.py",
+    "noqa_row": 1
+  },
+  {
+    "code": "F841",
+    "message": "Local variable `x` is assigned to but never used",
+    "fix": {
+      "message": "Remove assignment to unused variable `x`",
+      "edits": [
+        {
+          "content": "",
+          "location": {
+            "row": 6,
+            "column": 4
+          },
+          "end_location": {
+            "row": 6,
+            "column": 9
+          }
+        }
+      ]
+    },
+    "location": {
+      "row": 6,
+      "column": 5
+    },
+    "end_location": {
+      "row": 6,
+      "column": 6
+    },
+    "filename": "fib.py",
+    "noqa_row": 1
+  },
+  {
+    "code": "F821",
+    "message": "Undefined name `a`",
+    "fix": null,
+    "location": {
+      "row": 1,
+      "column": 4
+    },
+    "end_location": {
+      "row": 1,
+      "column": 5
+    },
+    "filename": "undef.py",
+    "noqa_row": 1
+  }
+]

crates/ruff/src/message/snapshots/ruff__message__junit__tests__output.snap

@@ -0,0 +1,21 @@
+---
+source: crates/ruff/src/message/junit.rs
+expression: content
+---
+<?xml version="1.0" encoding="UTF-8"?>
+<testsuites name="ruff" tests="3" failures="3" errors="0">
+    <testsuite name="fib.py" tests="2" disabled="0" errors="0" failures="2" package="org.ruff">
+        <testcase name="org.ruff.F401" classname="fib" line="1" column="8">
+            <failure message="`os` imported but unused">line 1, col 8, `os` imported but unused</failure>
+        </testcase>
+        <testcase name="org.ruff.F841" classname="fib" line="6" column="5">
+            <failure message="Local variable `x` is assigned to but never used">line 6, col 5, Local variable `x` is assigned to but never used</failure>
+        </testcase>
+    </testsuite>
+    <testsuite name="undef.py" tests="1" disabled="0" errors="0" failures="1" package="org.ruff">
+        <testcase name="org.ruff.F821" classname="undef" line="1" column="4">
+            <failure message="Undefined name `a`">line 1, col 4, Undefined name `a`</failure>
+        </testcase>
+    </testsuite>
+</testsuites>
+