Bump version to 0.0.206

.github/workflows/ci.yaml

@@ -116,18 +116,12 @@ jobs:
             ${{ runner.os }}-build-${{ env.cache-name }}-
             ${{ runner.os }}-build-
             ${{ runner.os }}-
+      - run: cargo install cargo-insta
       - run: pip install black[d]==22.12.0
       - name: Run tests
         run: |
-          export INSTA_SNAPSHOT_REFERENCES_FILE="$(mktemp)"
-          cargo test --all
-          USED_SNAPSHOTS=$(cat $INSTA_SNAPSHOT_REFERENCES_FILE | xargs realpath --relative-to $PWD)
-          UNUSED_SNAPSHOTS=$(cat <(git ls-files '*.snap') <(echo "$USED_SNAPSHOTS") | sort | uniq -u)
-          if [ ! -z "$UNUSED_SNAPSHOTS" ]; then
-            echo "Found unused snapshots:"
-            echo "$UNUSED_SNAPSHOTS"
-            exit 1
-          fi
+          cargo insta test --all --delete-unreferenced-snapshots
+          git diff --exit-code
       - run: cargo test --package ruff --test black_compatibility_test -- --ignored
 
 # TODO(charlie): Re-enable the `wasm-pack` tests.

.gitignore

@@ -181,3 +181,4 @@ cython_debug/
 #  and can be added to the global gitignore or merged into this file.  For a more nuclear
 #  option (not recommended) you can uncomment the following to ignore the entire idea folder.
 .idea/
+.vimspector.json

.pre-commit-config.yaml

@@ -1,6 +1,6 @@
 repos:
   - repo: https://github.com/charliermarsh/ruff-pre-commit
-    rev: v0.0.205
+    rev: v0.0.206
     hooks:
       - id: ruff
 

Cargo.lock

@@ -750,7 +750,7 @@ checksum = "0ce7134b9999ecaf8bcd65542e436736ef32ddca1b3e06094cb6ec5755203b80"
 
 [[package]]
 name = "flake8-to-ruff"
-version = "0.0.205-dev.0"
+version = "0.0.206-dev.0"
 dependencies = [
  "anyhow",
  "clap 4.0.32",
@@ -1878,7 +1878,7 @@ dependencies = [
 
 [[package]]
 name = "ruff"
-version = "0.0.205"
+version = "0.0.206"
 dependencies = [
  "annotate-snippets 0.9.1",
  "anyhow",
@@ -1946,7 +1946,7 @@ dependencies = [
 
 [[package]]
 name = "ruff_dev"
-version = "0.0.205"
+version = "0.0.206"
 dependencies = [
  "anyhow",
  "clap 4.0.32",
@@ -1967,7 +1967,7 @@ dependencies = [
 
 [[package]]
 name = "ruff_macros"
-version = "0.0.205"
+version = "0.0.206"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -2010,7 +2010,7 @@ dependencies = [
 [[package]]
 name = "rustpython-ast"
 version = "0.1.0"
-source = "git+https://github.com/RustPython/RustPython.git?rev=8cb2b8292062adf13bde1b863a9b02c9f0bda3dd#8cb2b8292062adf13bde1b863a9b02c9f0bda3dd"
+source = "git+https://github.com/RustPython/RustPython.git?rev=71becd4059fdce4bce7010f1208ed3b1c883abba#71becd4059fdce4bce7010f1208ed3b1c883abba"
 dependencies = [
  "num-bigint",
  "rustpython-common",
@@ -2020,7 +2020,7 @@ dependencies = [
 [[package]]
 name = "rustpython-common"
 version = "0.0.0"
-source = "git+https://github.com/RustPython/RustPython.git?rev=8cb2b8292062adf13bde1b863a9b02c9f0bda3dd#8cb2b8292062adf13bde1b863a9b02c9f0bda3dd"
+source = "git+https://github.com/RustPython/RustPython.git?rev=71becd4059fdce4bce7010f1208ed3b1c883abba#71becd4059fdce4bce7010f1208ed3b1c883abba"
 dependencies = [
  "ascii",
  "cfg-if 1.0.0",
@@ -2043,7 +2043,7 @@ dependencies = [
 [[package]]
 name = "rustpython-compiler-core"
 version = "0.1.2"
-source = "git+https://github.com/RustPython/RustPython.git?rev=8cb2b8292062adf13bde1b863a9b02c9f0bda3dd#8cb2b8292062adf13bde1b863a9b02c9f0bda3dd"
+source = "git+https://github.com/RustPython/RustPython.git?rev=71becd4059fdce4bce7010f1208ed3b1c883abba#71becd4059fdce4bce7010f1208ed3b1c883abba"
 dependencies = [
  "bincode",
  "bitflags",
@@ -2060,7 +2060,7 @@ dependencies = [
 [[package]]
 name = "rustpython-parser"
 version = "0.1.2"
-source = "git+https://github.com/RustPython/RustPython.git?rev=8cb2b8292062adf13bde1b863a9b02c9f0bda3dd#8cb2b8292062adf13bde1b863a9b02c9f0bda3dd"
+source = "git+https://github.com/RustPython/RustPython.git?rev=71becd4059fdce4bce7010f1208ed3b1c883abba#71becd4059fdce4bce7010f1208ed3b1c883abba"
 dependencies = [
  "ahash",
  "anyhow",

Cargo.toml

@@ -6,7 +6,7 @@ members = [
 
 [package]
 name = "ruff"
-version = "0.0.205"
+version = "0.0.206"
 authors = ["Charlie Marsh <charlie.r.marsh@gmail.com>"]
 edition = "2021"
 rust-version = "1.65.0"
@@ -51,11 +51,11 @@ path-absolutize = { version = "3.0.14", features = ["once_cell_cache", "use_unix
 quick-junit = { version = "0.3.2" }
 regex = { version = "1.6.0" }
 ropey = { version = "1.5.0", features = ["cr_lines", "simd"], default-features = false }
-ruff_macros = { version = "0.0.205", path = "ruff_macros" }
+ruff_macros = { version = "0.0.206", path = "ruff_macros" }
 rustc-hash = { version = "1.1.0" }
-rustpython-ast = { features = ["unparse"], git = "https://github.com/RustPython/RustPython.git", rev = "8cb2b8292062adf13bde1b863a9b02c9f0bda3dd" }
-rustpython-common = { git = "https://github.com/RustPython/RustPython.git", rev = "8cb2b8292062adf13bde1b863a9b02c9f0bda3dd" }
-rustpython-parser = { features = ["lalrpop"], git = "https://github.com/RustPython/RustPython.git", rev = "8cb2b8292062adf13bde1b863a9b02c9f0bda3dd" }
+rustpython-ast = { features = ["unparse"], git = "https://github.com/RustPython/RustPython.git", rev = "71becd4059fdce4bce7010f1208ed3b1c883abba" }
+rustpython-common = { git = "https://github.com/RustPython/RustPython.git", rev = "71becd4059fdce4bce7010f1208ed3b1c883abba" }
+rustpython-parser = { features = ["lalrpop"], git = "https://github.com/RustPython/RustPython.git", rev = "71becd4059fdce4bce7010f1208ed3b1c883abba" }
 schemars = { version = "0.8.11" }
 semver = { version = "1.0.16" }
 serde = { version = "1.0.147", features = ["derive"] }

README.md

@@ -8,7 +8,11 @@
 An extremely fast Python linter, written in Rust.
 
 <p align="center">
-  <img alt="Bar chart with benchmark results" src="https://user-images.githubusercontent.com/1309177/187504482-6d9df992-a81d-4e86-9f6a-d958741c8182.svg">
+  <picture align="center">
+    <source media="(prefers-color-scheme: dark)" srcset="https://user-images.githubusercontent.com/1309177/210156880-a97c2a0d-2c03-4393-8695-36547935a94e.svg">
+    <source media="(prefers-color-scheme: light)" srcset="https://user-images.githubusercontent.com/1309177/210156881-a88fd142-5008-4695-9407-d028cec3eff7.svg">
+    <img alt="Shows a bar chart with benchmark results." src="https://user-images.githubusercontent.com/1309177/210156881-a88fd142-5008-4695-9407-d028cec3eff7.svg">
+  </picture>
 </p>
 
 <p align="center">
@@ -169,7 +173,7 @@ Ruff also works with [pre-commit](https://pre-commit.com):
 ```yaml
 - repo: https://github.com/charliermarsh/ruff-pre-commit
   # Ruff version.
-  rev: 'v0.0.205'
+  rev: 'v0.0.206'
   hooks:
     - id: ruff
       # Respect `exclude` and `extend-exclude` settings.
@@ -682,7 +686,9 @@ For more, see [pyupgrade](https://pypi.org/project/pyupgrade/3.2.0/) on PyPI.
 | UP021 | ReplaceUniversalNewlines | `universal_newlines` is deprecated, use `text` | 🛠 |
 | UP022 | ReplaceStdoutStderr | Sending stdout and stderr to pipe is deprecated, use `capture_output` | 🛠 |
 | UP023 | RewriteCElementTree | `cElementTree` is deprecated, use `ElementTree` | 🛠 |
+| UP024 | OSErrorAlias | Replace aliased errors with `OSError` | 🛠 |
 | UP025 | RewriteUnicodeLiteral | Remove unicode literals from strings | 🛠 |
+| UP026 | RewriteMockImport | `mock` is deprecated, use `unittest.mock` | 🛠 |
 
 ### pep8-naming (N)
 
@@ -1301,7 +1307,7 @@ natively, including:
 - [`pep8-naming`](https://pypi.org/project/pep8-naming/)
 - [`pydocstyle`](https://pypi.org/project/pydocstyle/)
 - [`pygrep-hooks`](https://github.com/pre-commit/pygrep-hooks) (3/10)
-- [`pyupgrade`](https://pypi.org/project/pyupgrade/) (20/33)
+- [`pyupgrade`](https://pypi.org/project/pyupgrade/) (21/33)
 - [`yesqa`](https://github.com/asottile/yesqa)
 
 Note that, in some cases, Ruff uses different error code prefixes than would be found in the
@@ -1360,7 +1366,7 @@ Today, Ruff can be used to replace Flake8 when used with any of the following pl
 Ruff can also replace [`isort`](https://pypi.org/project/isort/),
 [`yesqa`](https://github.com/asottile/yesqa), [`eradicate`](https://pypi.org/project/eradicate/),
 [`pygrep-hooks`](https://github.com/pre-commit/pygrep-hooks) (3/10), and a subset of the rules
-implemented in [`pyupgrade`](https://pypi.org/project/pyupgrade/) (20/33).
+implemented in [`pyupgrade`](https://pypi.org/project/pyupgrade/) (21/33).
 
 If you're looking to use Ruff, but rely on an unsupported Flake8 plugin, free to file an Issue.
 

flake8_to_ruff/Cargo.lock

@@ -771,7 +771,7 @@ checksum = "0ce7134b9999ecaf8bcd65542e436736ef32ddca1b3e06094cb6ec5755203b80"
 
 [[package]]
 name = "flake8_to_ruff"
-version = "0.0.205"
+version = "0.0.206"
 dependencies = [
  "anyhow",
  "clap",
@@ -1975,7 +1975,7 @@ dependencies = [
 
 [[package]]
 name = "ruff"
-version = "0.0.205"
+version = "0.0.206"
 dependencies = [
  "anyhow",
  "bincode",

flake8_to_ruff/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "flake8-to-ruff"
-version = "0.0.205-dev.0"
+version = "0.0.206-dev.0"
 edition = "2021"
 
 [lib]

foo.py

@@ -0,0 +1,3 @@
+import mock.mock
+
+x = mock.mock.Mock()

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "maturin"
 
 [project]
 name = "ruff"
-version = "0.0.205"
+version = "0.0.206"
 description = "An extremely fast Python linter, written in Rust."
 authors = [
   { name = "Charlie Marsh", email = "charlie.r.marsh@gmail.com" },

resources/test/fixtures/flake8_return/RET504.py

@@ -137,6 +137,14 @@ def x():
     return a
 
 
+# Considered OK, since attribute assignments can have side effects.
+class X:
+    def x(self):
+        a = self.property
+        self.property = None
+        return a
+
+
 # Test cases for using value for assignment then returning it
 # See:https://github.com/afonasev/flake8-return/issues/47
 def resolve_from_url(self, url: str) -> dict:
@@ -238,13 +246,16 @@ def close(self):
             report(traceback.format_exc())
     return any_failed
 
+
 def global_assignment():
     global X
     X = 1
     return X
 
+
 def nonlocal_assignment():
     X = 1
+
     def inner():
         nonlocal X
         X = 1

resources/test/fixtures/pydocstyle/D400.py

@@ -35,7 +35,6 @@ def f():
     ...
 
 
-
 def f():
     r"Here's a line without a period"
     ...
@@ -71,3 +70,24 @@ def f():
     Here's a line without a period,
     but here's the next line with trailing space """
     ...
+
+
+def f(rounds: list[int], number: int) -> bool:
+    """
+    :param rounds: list - rounds played.
+    :param number: int - round number.
+    :return:  bool - was the round played?
+    """
+    return number in rounds
+
+
+def f(rounds: list[int], number: int) -> bool:
+    """
+    Args:
+        rounds (list): rounds played.
+        number (int): round number.
+
+    Returns:
+        bool: was the round played?
+    """
+    return number in rounds

resources/test/fixtures/pyflakes/F541.py

@@ -20,7 +20,8 @@ v = 23.234234
 
 # OK
 f"{v:0.2f}"
+f"{f'{v:0.2f}'}"
 
-# OK (false negatives)
+# Errors
 f"{v:{f'0.2f'}}"
 f"{f''}"

resources/test/fixtures/pyflakes/F821_0.py

@@ -89,7 +89,8 @@ A = (
     f'B'
     f'{B}'
 )
-
+C = f'{A:{B}}'
+C = f'{A:{f"{B}"}}'
 
 from typing import Annotated, Literal
 

resources/test/fixtures/pyupgrade/UP024_0.py

@@ -0,0 +1,98 @@
+import mmap, select, socket
+from mmap import error
+# These should be fixed
+try:
+    pass
+except EnvironmentError:
+    pass
+
+try:
+    pass
+except IOError:
+    pass
+
+try:
+    pass
+except WindowsError:
+    pass
+
+try:
+    pass
+except mmap.error:
+    pass
+
+try:
+    pass
+except select.error:
+    pass
+
+try:
+    pass
+except socket.error:
+    pass
+
+try:
+    pass
+except error:
+    pass
+
+# Should NOT be in parentheses when replaced
+
+try:
+    pass
+except (IOError,):
+    pass
+try:
+    pass
+except (mmap.error,):
+    pass
+try:
+    pass
+except (EnvironmentError, IOError, OSError, select.error):
+    pass
+
+# Should be kept in parentheses (because multiple)
+
+try:
+    pass
+except (IOError, KeyError, OSError):
+    pass
+
+# First should change, second should not
+from .mmap import error
+try:
+    pass
+except (IOError, error):
+    pass
+# These should not change
+
+from foo import error
+
+try:
+    pass
+except (OSError, error):
+    pass
+
+try:
+    pass
+except:
+    pass
+
+try:
+    pass
+except AssertionError:
+    pass
+try:
+    pass
+except (mmap).error:
+    pass
+
+try:
+    pass
+except OSError:
+    pass
+
+try:
+    pass
+except (OSError, KeyError):
+    pass

resources/test/fixtures/pyupgrade/UP024_1.py

@@ -0,0 +1,17 @@
+import mmap, socket, select
+
+try:
+    pass
+except (OSError, mmap.error, IOError):
+    pass
+except (OSError, socket.error, KeyError):
+    pass
+
+try:
+    pass
+except (
+    OSError,
+    select.error,
+    IOError,
+):
+    pass

resources/test/fixtures/pyupgrade/UP024_2.py

@@ -0,0 +1,50 @@
+# These should not change
+raise ValueError
+raise ValueError(1)
+
+from .mmap import error
+raise error
+
+# Testing the modules
+import socket, mmap, select
+raise socket.error
+raise mmap.error
+raise select.error
+
+raise socket.error()
+raise mmap.error(1)
+raise select.error(1, 2)
+
+raise socket.error(
+    1,
+    2,
+    3,
+)
+
+from mmap import error
+raise error
+
+from socket import error
+raise error(1)
+
+from select import error
+raise error(1, 2)
+
+# Testing the names
+raise EnvironmentError
+raise IOError
+raise WindowsError
+
+raise EnvironmentError()
+raise IOError(1)
+raise WindowsError(1, 2)
+
+raise EnvironmentError(
+    1,
+    2,
+    3,
+)
+
+raise WindowsError
+raise EnvironmentError(1)
+raise IOError(1, 2)

resources/test/fixtures/pyupgrade/UP026.py

@@ -0,0 +1,74 @@
+# These should be changed
+if True:
+    import mock
+
+if True:
+    import mock, sys
+
+# This goes to from unitest import mock
+import mock.mock
+
+# Mock should go on a new line as `from unittest import mock`
+import contextlib, mock, sys
+
+# Mock should go on a new line as `from unittest import mock`
+import mock, sys
+x = "This code should be preserved one line below the mock"
+
+# Mock should go on a new line as `from unittest import mock`
+from mock import mock
+
+# Should keep trailing comma
+from mock import (
+    mock,
+    a,
+    b,
+    c,
+)
+
+# Should not get a trailing comma
+from mock import (
+    mock,
+    a,
+    b,
+    c
+)
+
+if True:
+    if False:
+        from mock import (
+            mock,
+            a,
+            b,
+            c
+        )
+
+# These should not change:
+import os, io
+
+# Mock should go on a new line as `from unittest import mock`
+import mock, mock
+
+# Mock should go on a new line as `from unittest import mock as foo`
+import mock as foo
+
+# Mock should go on a new line as `from unittest import mock as foo`
+from mock import mock as foo
+
+if True:
+    # This should yield multiple, aliased imports.
+    import mock as foo, mock as bar, mock
+
+    # This should yield multiple, aliased imports, and preserve `os`.
+    import mock as foo, mock as bar, mock, os
+
+if True:
+    # This should yield multiple, aliased imports.
+    from mock import mock as foo, mock as bar, mock
+
+
+# This should be unchanged.
+x = mock.Mock()
+
+# This should change to `mock.Mock`().
+x = mock.mock.Mock()

ruff.schema.json

@@ -909,7 +909,9 @@
         "UP021",
         "UP022",
         "UP023",
+        "UP024",
         "UP025",
+        "UP026",
         "W",
         "W2",
         "W29",

ruff_dev/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "ruff_dev"
-version = "0.0.205"
+version = "0.0.206"
 edition = "2021"
 
 [dependencies]
@@ -11,9 +11,9 @@ itertools = { version = "0.10.5" }
 libcst = { git = "https://github.com/charliermarsh/LibCST", rev = "f2f0b7a487a8725d161fe8b3ed73a6758b21e177" }
 once_cell = { version = "1.16.0" }
 ruff = { path = ".." }
-rustpython-ast = { features = ["unparse"], git = "https://github.com/RustPython/RustPython.git", rev = "8cb2b8292062adf13bde1b863a9b02c9f0bda3dd" }
-rustpython-common = { git = "https://github.com/RustPython/RustPython.git", rev = "8cb2b8292062adf13bde1b863a9b02c9f0bda3dd" }
-rustpython-parser = { features = ["lalrpop"], git = "https://github.com/RustPython/RustPython.git", rev = "8cb2b8292062adf13bde1b863a9b02c9f0bda3dd" }
+rustpython-ast = { features = ["unparse"], git = "https://github.com/RustPython/RustPython.git", rev = "71becd4059fdce4bce7010f1208ed3b1c883abba" }
+rustpython-common = { git = "https://github.com/RustPython/RustPython.git", rev = "71becd4059fdce4bce7010f1208ed3b1c883abba" }
+rustpython-parser = { features = ["lalrpop"], git = "https://github.com/RustPython/RustPython.git", rev = "71becd4059fdce4bce7010f1208ed3b1c883abba" }
 schemars = { version = "0.8.11" }
 serde_json = {version="1.0.91"}
 strum = { version = "0.24.1", features = ["strum_macros"] }

ruff_macros/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "ruff_macros"
-version = "0.0.205"
+version = "0.0.206"
 edition = "2021"
 
 [lib]

src/ast/helpers.rs

@@ -335,20 +335,17 @@ pub fn to_absolute(relative: Location, base: Location) -> Location {
 
 /// Return `true` if a `Stmt` has leading content.
 pub fn match_leading_content(stmt: &Stmt, locator: &SourceCodeLocator) -> bool {
-    let range = Range {
-        location: Location::new(stmt.location.row(), 0),
-        end_location: stmt.location,
-    };
+    let range = Range::new(Location::new(stmt.location.row(), 0), stmt.location);
     let prefix = locator.slice_source_code_range(&range);
     prefix.chars().any(|char| !char.is_whitespace())
 }
 
 /// Return `true` if a `Stmt` has trailing content.
 pub fn match_trailing_content(stmt: &Stmt, locator: &SourceCodeLocator) -> bool {
-    let range = Range {
-        location: stmt.end_location.unwrap(),
-        end_location: Location::new(stmt.end_location.unwrap().row() + 1, 0),
-    };
+    let range = Range::new(
+        stmt.end_location.unwrap(),
+        Location::new(stmt.end_location.unwrap().row() + 1, 0),
+    );
     let suffix = locator.slice_source_code_range(&range);
     for char in suffix.chars() {
         if char == '#' {
@@ -384,10 +381,7 @@ pub fn identifier_range(stmt: &Stmt, locator: &SourceCodeLocator) -> Range {
         let contents = locator.slice_source_code_range(&Range::from_located(stmt));
         for (start, tok, end) in lexer::make_tokenizer_located(&contents, stmt.location).flatten() {
             if matches!(tok, Tok::Name { .. }) {
-                return Range {
-                    location: start,
-                    end_location: end,
-                };
+                return Range::new(start, end);
             }
         }
         error!("Failed to find identifier for {:?}", stmt);
@@ -419,20 +413,15 @@ pub fn excepthandler_name_range(
     match (name, type_) {
         (Some(_), Some(type_)) => {
             let type_end_location = type_.end_location.unwrap();
-            let contents = locator.slice_source_code_range(&Range {
-                location: type_end_location,
-                end_location: body[0].location,
-            });
+            let contents =
+                locator.slice_source_code_range(&Range::new(type_end_location, body[0].location));
             let range = lexer::make_tokenizer_located(&contents, type_end_location)
                 .flatten()
                 .tuple_windows()
                 .find(|(tok, next_tok)| {
                     matches!(tok.1, Tok::As) && matches!(next_tok.1, Tok::Name { .. })
                 })
-                .map(|((..), (location, _, end_location))| Range {
-                    location,
-                    end_location,
-                });
+                .map(|((..), (location, _, end_location))| Range::new(location, end_location));
             range
         }
         _ => None,
@@ -506,10 +495,10 @@ pub fn preceded_by_continuation(stmt: &Stmt, locator: &SourceCodeLocator) -> boo
     // make conservative choices.
     // TODO(charlie): Come up with a more robust strategy.
     if stmt.location.row() > 1 {
-        let range = Range {
-            location: Location::new(stmt.location.row() - 1, 0),
-            end_location: Location::new(stmt.location.row(), 0),
-        };
+        let range = Range::new(
+            Location::new(stmt.location.row() - 1, 0),
+            Location::new(stmt.location.row(), 0),
+        );
         let line = locator.slice_source_code_range(&range);
         if line.trim().ends_with('\\') {
             return true;
@@ -733,10 +722,7 @@ y = 2
         let locator = SourceCodeLocator::new(contents);
         assert_eq!(
             identifier_range(stmt, &locator),
-            Range {
-                location: Location::new(1, 4),
-                end_location: Location::new(1, 5),
-            }
+            Range::new(Location::new(1, 4), Location::new(1, 5),)
         );
 
         let contents = r#"
@@ -750,10 +736,7 @@ def \
         let locator = SourceCodeLocator::new(contents);
         assert_eq!(
             identifier_range(stmt, &locator),
-            Range {
-                location: Location::new(2, 2),
-                end_location: Location::new(2, 3),
-            }
+            Range::new(Location::new(2, 2), Location::new(2, 3),)
         );
 
         let contents = "class Class(): pass".trim();
@@ -762,10 +745,7 @@ def \
         let locator = SourceCodeLocator::new(contents);
         assert_eq!(
             identifier_range(stmt, &locator),
-            Range {
-                location: Location::new(1, 6),
-                end_location: Location::new(1, 11),
-            }
+            Range::new(Location::new(1, 6), Location::new(1, 11),)
         );
 
         let contents = "class Class: pass".trim();
@@ -774,10 +754,7 @@ def \
         let locator = SourceCodeLocator::new(contents);
         assert_eq!(
             identifier_range(stmt, &locator),
-            Range {
-                location: Location::new(1, 6),
-                end_location: Location::new(1, 11),
-            }
+            Range::new(Location::new(1, 6), Location::new(1, 11),)
         );
 
         let contents = r#"
@@ -791,10 +768,7 @@ class Class():
         let locator = SourceCodeLocator::new(contents);
         assert_eq!(
             identifier_range(stmt, &locator),
-            Range {
-                location: Location::new(2, 6),
-                end_location: Location::new(2, 11),
-            }
+            Range::new(Location::new(2, 6), Location::new(2, 11),)
         );
 
         let contents = r#"x = y + 1"#.trim();
@@ -803,10 +777,7 @@ class Class():
         let locator = SourceCodeLocator::new(contents);
         assert_eq!(
             identifier_range(stmt, &locator),
-            Range {
-                location: Location::new(1, 0),
-                end_location: Location::new(1, 9),
-            }
+            Range::new(Location::new(1, 0), Location::new(1, 9),)
         );
 
         Ok(())

src/ast/types.rs

@@ -22,12 +22,16 @@ pub struct Range {
 }
 
 impl Range {
-    pub fn from_located<T>(located: &Located<T>) -> Self {
-        Range {
-            location: located.location,
-            end_location: located.end_location.unwrap(),
+    pub fn new(location: Location, end_location: Location) -> Self {
+        Self {
+            location,
+            end_location,
         }
     }
+
+    pub fn from_located<T>(located: &Located<T>) -> Self {
+        Range::new(located.location, located.end_location.unwrap())
+    }
 }
 
 #[derive(Debug)]

src/ast/visitor.rs

@@ -38,6 +38,9 @@ pub trait Visitor<'a> {
     fn visit_excepthandler(&mut self, excepthandler: &'a Excepthandler) {
         walk_excepthandler(self, excepthandler);
     }
+    fn visit_format_spec(&mut self, format_spec: &'a Expr) {
+        walk_expr(self, format_spec);
+    }
     fn visit_arguments(&mut self, arguments: &'a Arguments) {
         walk_arguments(self, arguments);
     }
@@ -387,7 +390,7 @@ pub fn walk_expr<'a, V: Visitor<'a> + ?Sized>(visitor: &mut V, expr: &'a Expr) {
         } => {
             visitor.visit_expr(value);
             if let Some(expr) = format_spec {
-                visitor.visit_expr(expr);
+                visitor.visit_format_spec(expr);
             }
         }
         ExprKind::JoinedStr { values } => {

src/ast/whitespace.rs

@@ -9,10 +9,10 @@ use crate::checkers::ast::Checker;
 /// Extract the leading indentation from a line.
 pub fn indentation<'a, T>(checker: &'a Checker, located: &'a Located<T>) -> Cow<'a, str> {
     let range = Range::from_located(located);
-    checker.locator.slice_source_code_range(&Range {
-        location: Location::new(range.location.row(), 0),
-        end_location: Location::new(range.location.row(), range.location.column()),
-    })
+    checker.locator.slice_source_code_range(&Range::new(
+        Location::new(range.location.row(), 0),
+        Location::new(range.location.row(), range.location.column()),
+    ))
 }
 
 /// Extract the leading words from a line of text.

src/autofix/fixer.rs

@@ -68,10 +68,7 @@ fn apply_fixes<'a>(
         }
 
         // Add all contents from `last_pos` to `fix.location`.
-        let slice = locator.slice_source_code_range(&Range {
-            location: last_pos,
-            end_location: fix.location,
-        });
+        let slice = locator.slice_source_code_range(&Range::new(last_pos, fix.location));
         output.append(&slice);
 
         // Add the patch itself.

src/checkers/ast.rs

@@ -91,7 +91,6 @@ pub struct Checker<'a> {
     in_type_definition: bool,
     in_deferred_string_type_definition: bool,
     in_deferred_type_definition: bool,
-    in_f_string: bool,
     in_literal: bool,
     in_subscript: bool,
     seen_import_boundary: bool,
@@ -148,7 +147,6 @@ impl<'a> Checker<'a> {
             in_type_definition: false,
             in_deferred_string_type_definition: false,
             in_deferred_type_definition: false,
-            in_f_string: false,
             in_literal: false,
             in_subscript: false,
             seen_import_boundary: false,
@@ -215,10 +213,10 @@ impl<'a> Checker<'a> {
             return false;
         }
         let noqa_lineno = self.noqa_line_for.get(&lineno).unwrap_or(&lineno);
-        let line = self.locator.slice_source_code_range(&Range {
-            location: Location::new(*noqa_lineno, 0),
-            end_location: Location::new(noqa_lineno + 1, 0),
-        });
+        let line = self.locator.slice_source_code_range(&Range::new(
+            Location::new(*noqa_lineno, 0),
+            Location::new(noqa_lineno + 1, 0),
+        ));
         match noqa::extract_noqa_directive(&line) {
             Directive::None => false,
             Directive::All(..) => true,
@@ -643,6 +641,9 @@ where
                 if self.settings.enabled.contains(&CheckCode::UP023) {
                     pyupgrade::plugins::replace_c_element_tree(self, stmt);
                 }
+                if self.settings.enabled.contains(&CheckCode::UP026) {
+                    pyupgrade::plugins::rewrite_mock_import(self, stmt);
+                }
 
                 for alias in names {
                     if alias.node.name.contains('.') && alias.node.asname.is_none() {
@@ -854,6 +855,9 @@ where
                         pyupgrade::plugins::unnecessary_future_import(self, stmt, names);
                     }
                 }
+                if self.settings.enabled.contains(&CheckCode::UP026) {
+                    pyupgrade::plugins::rewrite_mock_import(self, stmt);
+                }
 
                 if self.settings.enabled.contains(&CheckCode::TID251) {
                     if let Some(module) = module {
@@ -1107,6 +1111,11 @@ where
                         flake8_errmsg::plugins::string_in_exception(self, exc);
                     }
                 }
+                if self.settings.enabled.contains(&CheckCode::UP024) {
+                    if let Some(item) = exc {
+                        pyupgrade::plugins::os_error_alias(self, item);
+                    }
+                }
             }
             StmtKind::AugAssign { target, .. } => {
                 self.handle_node_load(target);
@@ -1191,6 +1200,9 @@ where
                 if self.settings.enabled.contains(&CheckCode::B013) {
                     flake8_bugbear::plugins::redundant_tuple_in_exception_handler(self, handlers);
                 }
+                if self.settings.enabled.contains(&CheckCode::UP024) {
+                    pyupgrade::plugins::os_error_alias(self, handlers);
+                }
             }
             StmtKind::Assign { targets, value, .. } => {
                 if self.settings.enabled.contains(&CheckCode::E731) {
@@ -1472,7 +1484,6 @@ where
 
         self.push_expr(expr);
 
-        let prev_in_f_string = self.in_f_string;
         let prev_in_literal = self.in_literal;
         let prev_in_type_definition = self.in_type_definition;
 
@@ -1595,6 +1606,10 @@ where
                 if self.settings.enabled.contains(&CheckCode::UP019) {
                     pyupgrade::plugins::typing_text_str_alias(self, expr);
                 }
+                if self.settings.enabled.contains(&CheckCode::UP026) {
+                    pyupgrade::plugins::rewrite_mock_attribute(self, expr);
+                }
+
                 if self.settings.enabled.contains(&CheckCode::YTT202) {
                     flake8_2020::plugins::name_or_attribute(self, expr);
                 }
@@ -1716,6 +1731,9 @@ where
                 if self.settings.enabled.contains(&CheckCode::UP022) {
                     pyupgrade::plugins::replace_stdout_stderr(self, expr, keywords);
                 }
+                if self.settings.enabled.contains(&CheckCode::UP024) {
+                    pyupgrade::plugins::os_error_alias(self, expr);
+                }
 
                 // flake8-print
                 if self.settings.enabled.contains(&CheckCode::T201)
@@ -2159,9 +2177,7 @@ where
                 }
             }
             ExprKind::JoinedStr { values } => {
-                // Conversion flags are parsed as f-strings without placeholders, so skip
-                // nested f-strings, which would lead to false positives.
-                if !self.in_f_string && self.settings.enabled.contains(&CheckCode::F541) {
+                if self.settings.enabled.contains(&CheckCode::F541) {
                     if !values
                         .iter()
                         .any(|value| matches!(value.node, ExprKind::FormattedValue { .. }))
@@ -2665,9 +2681,7 @@ where
                 self.in_subscript = prev_in_subscript;
             }
             ExprKind::JoinedStr { .. } => {
-                self.in_f_string = true;
                 visitor::walk_expr(self, expr);
-                self.in_f_string = prev_in_f_string;
             }
             _ => visitor::walk_expr(self, expr),
         }
@@ -2686,7 +2700,6 @@ where
 
         self.in_type_definition = prev_in_type_definition;
         self.in_literal = prev_in_literal;
-        self.in_f_string = prev_in_f_string;
 
         self.pop_expr();
     }
@@ -2790,6 +2803,17 @@ where
         }
     }
 
+    fn visit_format_spec(&mut self, format_spec: &'b Expr) {
+        match &format_spec.node {
+            ExprKind::JoinedStr { values } => {
+                for value in values {
+                    self.visit_expr(value);
+                }
+            }
+            _ => unreachable!("Unexpected expression for format_spec"),
+        }
+    }
+
     fn visit_arguments(&mut self, arguments: &'b Arguments) {
         if self.settings.enabled.contains(&CheckCode::B006) {
             flake8_bugbear::plugins::mutable_argument_default(self, arguments);
@@ -3869,10 +3893,10 @@ impl<'a> Checker<'a> {
                 let content = self
                     .locator
                     .slice_source_code_range(&Range::from_located(expr));
-                let indentation = self.locator.slice_source_code_range(&Range {
-                    location: Location::new(expr.location.row(), 0),
-                    end_location: Location::new(expr.location.row(), expr.location.column()),
-                });
+                let indentation = self.locator.slice_source_code_range(&Range::new(
+                    Location::new(expr.location.row(), 0),
+                    Location::new(expr.location.row(), expr.location.column()),
+                ));
                 let body = pydocstyle::helpers::raw_contents(&content);
                 let docstring = Docstring {
                     kind: definition.kind,

src/checkers/noqa.rs

@@ -102,10 +102,7 @@ pub fn check_noqa(
                     if matches.is_empty() {
                         let mut check = Check::new(
                             CheckKind::UnusedNOQA(None),
-                            Range {
-                                location: Location::new(row + 1, start),
-                                end_location: Location::new(row + 1, end),
-                            },
+                            Range::new(Location::new(row + 1, start), Location::new(row + 1, end)),
                         );
                         if matches!(autofix, flags::Autofix::Enabled)
                             && settings.fixable.contains(check.kind.code())
@@ -169,10 +166,7 @@ pub fn check_noqa(
                                     .map(|code| (*code).to_string())
                                     .collect(),
                             })),
-                            Range {
-                                location: Location::new(row + 1, start),
-                                end_location: Location::new(row + 1, end),
-                            },
+                            Range::new(Location::new(row + 1, start), Location::new(row + 1, end)),
                         );
                         if matches!(autofix, flags::Autofix::Enabled)
                             && settings.fixable.contains(check.kind.code())

src/checks.rs

@@ -236,7 +236,9 @@ pub enum CheckCode {
     UP021,
     UP022,
     UP023,
+    UP024,
     UP025,
+    UP026,
     // pydocstyle
     D100,
     D101,
@@ -703,6 +705,12 @@ pub struct UnusedCodes {
     pub unmatched: Vec<String>,
 }
 
+#[derive(Debug, PartialEq, Eq, Serialize, Deserialize)]
+pub enum MockReference {
+    Import,
+    Attribute,
+}
+
 #[derive(AsRefStr, Debug, PartialEq, Eq, Serialize, Deserialize)]
 pub enum CheckKind {
     // pycodestyle errors
@@ -907,7 +915,9 @@ pub enum CheckKind {
     ReplaceUniversalNewlines,
     ReplaceStdoutStderr,
     RewriteCElementTree,
+    OSErrorAlias(Option<String>),
     RewriteUnicodeLiteral,
+    RewriteMockImport(MockReference),
     // pydocstyle
     BlankLineAfterLastSection(String),
     BlankLineAfterSection(String),
@@ -1301,7 +1311,9 @@ impl CheckCode {
             CheckCode::UP021 => CheckKind::ReplaceUniversalNewlines,
             CheckCode::UP022 => CheckKind::ReplaceStdoutStderr,
             CheckCode::UP023 => CheckKind::RewriteCElementTree,
+            CheckCode::UP024 => CheckKind::OSErrorAlias(None),
             CheckCode::UP025 => CheckKind::RewriteUnicodeLiteral,
+            CheckCode::UP026 => CheckKind::RewriteMockImport(MockReference::Import),
             // pydocstyle
             CheckCode::D100 => CheckKind::PublicModule,
             CheckCode::D101 => CheckKind::PublicClass,
@@ -1733,7 +1745,9 @@ impl CheckCode {
             CheckCode::UP021 => CheckCategory::Pyupgrade,
             CheckCode::UP022 => CheckCategory::Pyupgrade,
             CheckCode::UP023 => CheckCategory::Pyupgrade,
+            CheckCode::UP024 => CheckCategory::Pyupgrade,
             CheckCode::UP025 => CheckCategory::Pyupgrade,
+            CheckCode::UP026 => CheckCategory::Pyupgrade,
             CheckCode::W292 => CheckCategory::Pycodestyle,
             CheckCode::W605 => CheckCategory::Pycodestyle,
             CheckCode::YTT101 => CheckCategory::Flake82020,
@@ -1955,7 +1969,9 @@ impl CheckKind {
             CheckKind::ReplaceUniversalNewlines => &CheckCode::UP021,
             CheckKind::ReplaceStdoutStderr => &CheckCode::UP022,
             CheckKind::RewriteCElementTree => &CheckCode::UP023,
+            CheckKind::OSErrorAlias(..) => &CheckCode::UP024,
             CheckKind::RewriteUnicodeLiteral => &CheckCode::UP025,
+            CheckKind::RewriteMockImport(..) => &CheckCode::UP026,
             // pydocstyle
             CheckKind::BlankLineAfterLastSection(..) => &CheckCode::D413,
             CheckKind::BlankLineAfterSection(..) => &CheckCode::D410,
@@ -2715,7 +2731,11 @@ impl CheckKind {
             CheckKind::RewriteCElementTree => {
                 "`cElementTree` is deprecated, use `ElementTree`".to_string()
             }
+            CheckKind::OSErrorAlias(..) => "Replace aliased errors with `OSError`".to_string(),
             CheckKind::RewriteUnicodeLiteral => "Remove unicode literals from strings".to_string(),
+            CheckKind::RewriteMockImport(..) => {
+                "`mock` is deprecated, use `unittest.mock`".to_string()
+            }
             // pydocstyle
             CheckKind::FitsOnOneLine => "One-line docstring should fit on one line".to_string(),
             CheckKind::BlankLineAfterSummary => {
@@ -3129,8 +3149,8 @@ impl CheckKind {
         matches!(
             self,
             CheckKind::AmbiguousUnicodeCharacterString(..)
-                | CheckKind::AmbiguousUnicodeCharacterDocstring(..)
                 | CheckKind::AmbiguousUnicodeCharacterComment(..)
+                | CheckKind::AmbiguousUnicodeCharacterDocstring(..)
                 | CheckKind::BlankLineAfterLastSection(..)
                 | CheckKind::BlankLineAfterSection(..)
                 | CheckKind::BlankLineAfterSummary
@@ -3156,12 +3176,7 @@ impl CheckKind {
                 | CheckKind::MisplacedComparisonConstant(..)
                 | CheckKind::MissingReturnTypeSpecialMethod(..)
                 | CheckKind::NativeLiterals(..)
-                | CheckKind::OpenAlias
                 | CheckKind::NewLineAfterLastParagraph
-                | CheckKind::ReplaceUniversalNewlines
-                | CheckKind::ReplaceStdoutStderr
-                | CheckKind::RewriteCElementTree
-                | CheckKind::RewriteUnicodeLiteral
                 | CheckKind::NewLineAfterSectionName(..)
                 | CheckKind::NoBlankLineAfterFunction(..)
                 | CheckKind::NoBlankLineBeforeClass(..)
@@ -3174,16 +3189,23 @@ impl CheckKind {
                 | CheckKind::NoneComparison(..)
                 | CheckKind::NotInTest
                 | CheckKind::NotIsTest
+                | CheckKind::OSErrorAlias(..)
                 | CheckKind::OneBlankLineAfterClass(..)
                 | CheckKind::OneBlankLineBeforeClass(..)
+                | CheckKind::OpenAlias
                 | CheckKind::PEP3120UnnecessaryCodingComment
                 | CheckKind::PPrintFound
-                | CheckKind::PrintFound
                 | CheckKind::PercentFormatExtraNamedArguments(..)
+                | CheckKind::PrintFound
                 | CheckKind::RaiseNotImplemented
                 | CheckKind::RedundantOpenModes(..)
                 | CheckKind::RedundantTupleInExceptionHandler(..)
                 | CheckKind::RemoveSixCompat
+                | CheckKind::ReplaceStdoutStderr
+                | CheckKind::ReplaceUniversalNewlines
+                | CheckKind::RewriteCElementTree
+                | CheckKind::RewriteMockImport(..)
+                | CheckKind::RewriteUnicodeLiteral
                 | CheckKind::SectionNameEndsInColon(..)
                 | CheckKind::SectionNotOverIndented(..)
                 | CheckKind::SectionUnderlineAfterName(..)
@@ -3295,6 +3317,10 @@ impl CheckKind {
             }
             CheckKind::RewriteCElementTree => Some("Replace with `ElementTree`".to_string()),
             CheckKind::RewriteUnicodeLiteral => Some("Remove unicode prefix".to_string()),
+            CheckKind::RewriteMockImport(reference_type) => Some(match reference_type {
+                MockReference::Import => "Import from `unittest.mock` instead".to_string(),
+                MockReference::Attribute => "Replace `mock.mock` with `mock`".to_string(),
+            }),
             CheckKind::NewLineAfterSectionName(name) => {
                 Some(format!("Add newline after \"{name}\""))
             }
@@ -3313,6 +3339,10 @@ impl CheckKind {
             CheckKind::OneBlankLineAfterClass(..) => {
                 Some("Insert 1 blank line after class docstring".to_string())
             }
+            CheckKind::OSErrorAlias(name) => Some(match name {
+                None => "Replace with builtin `OSError`".to_string(),
+                Some(name) => format!("Replace `{name}` with builtin `OSError`"),
+            }),
             CheckKind::NoBlankLinesBetweenHeaderAndContent(..) => {
                 Some("Remove blank line(s)".to_string())
             }

src/checks_gen.rs

@@ -540,7 +540,9 @@ pub enum CheckCodePrefix {
     UP021,
     UP022,
     UP023,
+    UP024,
     UP025,
+    UP026,
     W,
     W2,
     W29,
@@ -773,7 +775,9 @@ impl CheckCodePrefix {
                 CheckCode::UP021,
                 CheckCode::UP022,
                 CheckCode::UP023,
+                CheckCode::UP024,
                 CheckCode::UP025,
+                CheckCode::UP026,
                 CheckCode::D100,
                 CheckCode::D101,
                 CheckCode::D102,
@@ -2452,7 +2456,9 @@ impl CheckCodePrefix {
                     CheckCode::UP021,
                     CheckCode::UP022,
                     CheckCode::UP023,
+                    CheckCode::UP024,
                     CheckCode::UP025,
+                    CheckCode::UP026,
                 ]
             }
             CheckCodePrefix::U0 => {
@@ -2485,7 +2491,9 @@ impl CheckCodePrefix {
                     CheckCode::UP021,
                     CheckCode::UP022,
                     CheckCode::UP023,
+                    CheckCode::UP024,
                     CheckCode::UP025,
+                    CheckCode::UP026,
                 ]
             }
             CheckCodePrefix::U00 => {
@@ -2702,7 +2710,9 @@ impl CheckCodePrefix {
                 CheckCode::UP021,
                 CheckCode::UP022,
                 CheckCode::UP023,
+                CheckCode::UP024,
                 CheckCode::UP025,
+                CheckCode::UP026,
             ],
             CheckCodePrefix::UP0 => vec![
                 CheckCode::UP001,
@@ -2727,7 +2737,9 @@ impl CheckCodePrefix {
                 CheckCode::UP021,
                 CheckCode::UP022,
                 CheckCode::UP023,
+                CheckCode::UP024,
                 CheckCode::UP025,
+                CheckCode::UP026,
             ],
             CheckCodePrefix::UP00 => vec![
                 CheckCode::UP001,
@@ -2774,13 +2786,17 @@ impl CheckCodePrefix {
                 CheckCode::UP021,
                 CheckCode::UP022,
                 CheckCode::UP023,
+                CheckCode::UP024,
                 CheckCode::UP025,
+                CheckCode::UP026,
             ],
             CheckCodePrefix::UP020 => vec![CheckCode::UP020],
             CheckCodePrefix::UP021 => vec![CheckCode::UP021],
             CheckCodePrefix::UP022 => vec![CheckCode::UP022],
             CheckCodePrefix::UP023 => vec![CheckCode::UP023],
+            CheckCodePrefix::UP024 => vec![CheckCode::UP024],
             CheckCodePrefix::UP025 => vec![CheckCode::UP025],
+            CheckCodePrefix::UP026 => vec![CheckCode::UP026],
             CheckCodePrefix::W => vec![CheckCode::W292, CheckCode::W605],
             CheckCodePrefix::W2 => vec![CheckCode::W292],
             CheckCodePrefix::W29 => vec![CheckCode::W292],
@@ -3352,7 +3368,9 @@ impl CheckCodePrefix {
             CheckCodePrefix::UP021 => SuffixLength::Three,
             CheckCodePrefix::UP022 => SuffixLength::Three,
             CheckCodePrefix::UP023 => SuffixLength::Three,
+            CheckCodePrefix::UP024 => SuffixLength::Three,
             CheckCodePrefix::UP025 => SuffixLength::Three,
+            CheckCodePrefix::UP026 => SuffixLength::Three,
             CheckCodePrefix::W => SuffixLength::Zero,
             CheckCodePrefix::W2 => SuffixLength::One,
             CheckCodePrefix::W29 => SuffixLength::Two,

src/cst/matchers.rs

@@ -1,5 +1,5 @@
 use anyhow::{bail, Result};
-use libcst_native::{Expr, Module, SmallStatement, Statement};
+use libcst_native::{Expr, Import, ImportFrom, Module, SmallStatement, Statement};
 
 pub fn match_module(module_text: &str) -> Result<Module> {
     match libcst_native::parse_module(module_text, None) {
@@ -19,3 +19,27 @@ pub fn match_expr<'a, 'b>(module: &'a mut Module<'b>) -> Result<&'a mut Expr<'b>
         bail!("Expected Statement::Simple")
     }
 }
+
+pub fn match_import<'a, 'b>(module: &'a mut Module<'b>) -> Result<&'a mut Import<'b>> {
+    if let Some(Statement::Simple(expr)) = module.body.first_mut() {
+        if let Some(SmallStatement::Import(expr)) = expr.body.first_mut() {
+            Ok(expr)
+        } else {
+            bail!("Expected SmallStatement::Expr")
+        }
+    } else {
+        bail!("Expected Statement::Simple")
+    }
+}
+
+pub fn match_import_from<'a, 'b>(module: &'a mut Module<'b>) -> Result<&'a mut ImportFrom<'b>> {
+    if let Some(Statement::Simple(expr)) = module.body.first_mut() {
+        if let Some(SmallStatement::ImportFrom(expr)) = expr.body.first_mut() {
+            Ok(expr)
+        } else {
+            bail!("Expected SmallStatement::Expr")
+        }
+    } else {
+        bail!("Expected Statement::Simple")
+    }
+}

src/directives.rs

@@ -110,10 +110,7 @@ pub fn extract_isort_directives(lxr: &[LexResult], locator: &SourceCodeLocator)
         }
 
         // TODO(charlie): Modify RustPython to include the comment text in the token.
-        let comment_text = locator.slice_source_code_range(&Range {
-            location: start,
-            end_location: end,
-        });
+        let comment_text = locator.slice_source_code_range(&Range::new(start, end));
 
         if comment_text == "# isort: split" {
             splits.push(start.row());

src/docstrings/constants.rs

@@ -1,4 +1,4 @@
-// See: https://docs.python.org/3/reference/lexical_analysis.html#string-and-bytes-literals.
+/// See: <https://docs.python.org/3/reference/lexical_analysis.html#string-and-bytes-literals>
 
 pub const TRIPLE_QUOTE_PREFIXES: &[&str] = &[
     "u\"\"\"", "u'''", "r\"\"\"", "r'''", "U\"\"\"", "U'''", "R\"\"\"", "R'''", "\"\"\"", "'''",

src/docstrings/styles.rs

@@ -5,21 +5,21 @@ use crate::docstrings::google::{GOOGLE_SECTION_NAMES, LOWERCASE_GOOGLE_SECTION_N
 use crate::docstrings::numpy::{LOWERCASE_NUMPY_SECTION_NAMES, NUMPY_SECTION_NAMES};
 
 pub(crate) enum SectionStyle {
-    NumPy,
+    Numpy,
     Google,
 }
 
 impl SectionStyle {
     pub(crate) fn section_names(&self) -> &Lazy<FxHashSet<&'static str>> {
         match self {
-            SectionStyle::NumPy => &NUMPY_SECTION_NAMES,
+            SectionStyle::Numpy => &NUMPY_SECTION_NAMES,
             SectionStyle::Google => &GOOGLE_SECTION_NAMES,
         }
     }
 
     pub(crate) fn lowercase_section_names(&self) -> &Lazy<FxHashSet<&'static str>> {
         match self {
-            SectionStyle::NumPy => &LOWERCASE_NUMPY_SECTION_NAMES,
+            SectionStyle::Numpy => &LOWERCASE_NUMPY_SECTION_NAMES,
             SectionStyle::Google => &LOWERCASE_GOOGLE_SECTION_NAMES,
         }
     }

src/eradicate/checks.rs

@@ -28,20 +28,11 @@ pub fn commented_out_code(
 ) -> Option<Check> {
     let location = Location::new(start.row(), 0);
     let end_location = Location::new(end.row() + 1, 0);
-    let line = locator.slice_source_code_range(&Range {
-        location,
-        end_location,
-    });
+    let line = locator.slice_source_code_range(&Range::new(location, end_location));
 
     // Verify that the comment is on its own line, and that it contains code.
     if is_standalone_comment(&line) && comment_contains_code(&line) {
-        let mut check = Check::new(
-            CheckKind::CommentedOutCode,
-            Range {
-                location: start,
-                end_location: end,
-            },
-        );
+        let mut check = Check::new(CheckKind::CommentedOutCode, Range::new(start, end));
         if matches!(autofix, flags::Autofix::Enabled)
             && settings.fixable.contains(&CheckCode::ERA001)
         {

src/flake8_builtins/snapshots/ruff__flake8_builtins__tests__A001_A001.py.snap

@@ -49,7 +49,7 @@ expression: checks
     column: 1
   end_location:
     row: 6
-    column: 13
+    column: 8
   fix: ~
   parent: ~
 - kind:

src/flake8_quotes/checks.rs

@@ -47,10 +47,7 @@ pub fn quotes(
     is_docstring: bool,
     settings: &Settings,
 ) -> Option<Check> {
-    let text = locator.slice_source_code_range(&Range {
-        location: start,
-        end_location: end,
-    });
+    let text = locator.slice_source_code_range(&Range::new(start, end));
 
     // Remove any prefixes (e.g., remove `u` from `u"foo"`).
     let last_quote_char = text.chars().last().unwrap();
@@ -76,10 +73,7 @@ pub fn quotes(
 
         Some(Check::new(
             CheckKind::BadQuotesDocstring(settings.docstring_quotes.clone()),
-            Range {
-                location: start,
-                end_location: end,
-            },
+            Range::new(start, end),
         ))
     } else if is_multiline {
         // If our string is or contains a known good string, ignore it.
@@ -94,10 +88,7 @@ pub fn quotes(
 
         Some(Check::new(
             CheckKind::BadQuotesMultilineString(settings.multiline_quotes.clone()),
-            Range {
-                location: start,
-                end_location: end,
-            },
+            Range::new(start, end),
         ))
     } else {
         let string_contents = &raw_text[1..raw_text.len() - 1];
@@ -112,10 +103,7 @@ pub fn quotes(
             {
                 return Some(Check::new(
                     CheckKind::AvoidQuoteEscape,
-                    Range {
-                        location: start,
-                        end_location: end,
-                    },
+                    Range::new(start, end),
                 ));
             }
             return None;
@@ -125,10 +113,7 @@ pub fn quotes(
         if !string_contents.contains(good_single(&settings.inline_quotes)) {
             return Some(Check::new(
                 CheckKind::BadQuotesInlineString(settings.inline_quotes.clone()),
-                Range {
-                    location: start,
-                    end_location: end,
-                },
+                Range::new(start, end),
             ));
         }
 

src/flake8_return/visitor.rs

@@ -38,6 +38,18 @@ impl<'a> ReturnVisitor<'a> {
                     .push(expr.location);
                 return;
             }
+            ExprKind::Attribute { .. } => {
+                // Attribute assignments are often side-effects (e.g., `self.property = value`),
+                // so we conservatively treat them as references to every known
+                // variable.
+                for name in self.stack.assigns.keys() {
+                    self.stack
+                        .refs
+                        .entry(name)
+                        .or_insert_with(Vec::new)
+                        .push(expr.location);
+                }
+            }
             _ => {}
         }
         visitor::walk_expr(self, expr);

src/flake8_simplify/plugins/key_in_dict.rs

@@ -1,9 +1,11 @@
 use rustpython_ast::{Cmpop, Expr, ExprKind};
 
+use crate::ast::helpers::create_expr;
 use crate::ast::types::Range;
 use crate::autofix::Fix;
 use crate::checkers::ast::Checker;
-use crate::checks::{Check, CheckCode, CheckKind};
+use crate::checks::{Check, CheckKind};
+use crate::source_code_generator::SourceCodeGenerator;
 
 /// SIM118
 fn key_in_dict(checker: &mut Checker, left: &Expr, right: &Expr, range: Range) {
@@ -29,13 +31,21 @@ fn key_in_dict(checker: &mut Checker, left: &Expr, right: &Expr, range: Range) {
         CheckKind::KeyInDict(left.to_string(), value.to_string()),
         range,
     );
-    if checker.patch(&CheckCode::SIM118) {
-        let content = right.to_string().replace(".keys()", "");
-        check.amend(Fix::replacement(
-            content,
-            right.location,
-            right.end_location.unwrap(),
-        ));
+    if checker.patch(check.kind.code()) {
+        let mut generator = SourceCodeGenerator::new(
+            checker.style.indentation(),
+            checker.style.quote(),
+            checker.style.line_ending(),
+        );
+        generator.unparse_expr(&create_expr(value.node.clone()), 0);
+
+        if let Ok(content) = generator.generate() {
+            check.amend(Fix::replacement(
+                content,
+                right.location,
+                right.end_location.unwrap(),
+            ));
+        }
     }
     checker.add_check(check);
 }
@@ -46,10 +56,7 @@ pub fn key_in_dict_for(checker: &mut Checker, target: &Expr, iter: &Expr) {
         checker,
         target,
         iter,
-        Range {
-            location: target.location,
-            end_location: iter.end_location.unwrap(),
-        },
+        Range::new(target.location, iter.end_location.unwrap()),
     );
 }
 

src/isort/comments.rs

@@ -22,10 +22,7 @@ pub fn collect_comments<'a>(range: &Range, locator: &'a SourceCodeLocator) -> Ve
         .filter_map(|(start, tok, end)| {
             if matches!(tok, Tok::Comment) {
                 Some(Comment {
-                    value: locator.slice_source_code_range(&Range {
-                        location: start,
-                        end_location: end,
-                    }),
+                    value: locator.slice_source_code_range(&Range::new(start, end)),
                     location: start,
                     end_location: end,
                 })

src/isort/mod.rs

@@ -23,12 +23,12 @@ use crate::SourceCodeLocator;
 mod categorize;
 mod comments;
 pub mod format;
-mod helpers;
+pub mod helpers;
 pub mod plugins;
 pub mod settings;
 mod sorting;
 pub mod track;
-mod types;
+pub mod types;
 
 #[derive(Debug)]
 pub struct AnnotatedAliasData<'a> {

src/isort/plugins.rs

@@ -19,18 +19,12 @@ use crate::{Check, Settings, SourceCodeLocator};
 fn extract_range(body: &[&Stmt]) -> Range {
     let location = body.first().unwrap().location;
     let end_location = body.last().unwrap().end_location.unwrap();
-    Range {
-        location,
-        end_location,
-    }
+    Range::new(location, end_location)
 }
 
 fn extract_indentation_range(body: &[&Stmt]) -> Range {
     let location = body.first().unwrap().location;
-    Range {
-        location: Location::new(location.row(), 0),
-        end_location: location,
-    }
+    Range::new(Location::new(location.row(), 0), location)
 }
 
 /// I001
@@ -57,10 +51,10 @@ pub fn check_imports(
 
     // Extract comments. Take care to grab any inline comments from the last line.
     let comments = comments::collect_comments(
-        &Range {
-            location: range.location,
-            end_location: Location::new(range.end_location.row() + 1, 0),
-        },
+        &Range::new(
+            range.location,
+            Location::new(range.end_location.row() + 1, 0),
+        ),
         locator,
     );
 
@@ -90,10 +84,10 @@ pub fn check_imports(
     );
 
     // Expand the span the entire range, including leading and trailing space.
-    let range = Range {
-        location: Location::new(range.location.row(), 0),
-        end_location: Location::new(range.end_location.row() + 1 + num_trailing_lines, 0),
-    };
+    let range = Range::new(
+        Location::new(range.location.row(), 0),
+        Location::new(range.end_location.row() + 1 + num_trailing_lines, 0),
+    );
     let actual = dedent(&locator.slice_source_code_range(&range));
     if actual == dedent(&expected) {
         None

src/linter.rs

@@ -120,10 +120,7 @@ pub(crate) fn check_path(
                 if settings.enabled.contains(&CheckCode::E999) {
                     checks.push(Check::new(
                         CheckKind::SyntaxError(parse_error.error.to_string()),
-                        Range {
-                            location: parse_error.location,
-                            end_location: parse_error.location,
-                        },
+                        Range::new(parse_error.location, parse_error.location),
                     ));
                 }
             }

src/message.rs

@@ -55,22 +55,18 @@ pub struct Source {
 
 impl Source {
     pub fn from_check(check: &Check, locator: &SourceCodeLocator) -> Self {
-        let source = locator.slice_source_code_range(&Range {
-            location: Location::new(check.location.row(), 0),
-            // Checks can already extend one-past-the-end per Ropey's semantics. 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.
-            end_location: if check.end_location.column() == 0 {
-                check.end_location
-            } else {
-                Location::new(check.end_location.row() + 1, 0)
-            },
-        });
+        let location = Location::new(check.location.row(), 0);
+        // Checks can already extend one-past-the-end per Ropey's semantics. 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 check.end_location.column() == 0 {
+            check.end_location
+        } else {
+            Location::new(check.end_location.row() + 1, 0)
+        };
+        let source = locator.slice_source_code_range(&Range::new(location, end_location));
         let num_chars_in_range = locator
-            .slice_source_code_range(&Range {
-                location: check.location,
-                end_location: check.end_location,
-            })
+            .slice_source_code_range(&Range::new(check.location, check.end_location))
             .chars()
             .count();
         Source {

src/noqa.rs

@@ -248,10 +248,7 @@ mod tests {
 
         let checks = vec![Check::new(
             CheckKind::UnusedVariable("x".to_string()),
-            Range {
-                location: Location::new(1, 0),
-                end_location: Location::new(1, 0),
-            },
+            Range::new(Location::new(1, 0), Location::new(1, 0)),
         )];
         let contents = "x = 1";
         let noqa_line_for = IntMap::default();
@@ -269,17 +266,11 @@ mod tests {
         let checks = vec![
             Check::new(
                 CheckKind::AmbiguousVariableName("x".to_string()),
-                Range {
-                    location: Location::new(1, 0),
-                    end_location: Location::new(1, 0),
-                },
+                Range::new(Location::new(1, 0), Location::new(1, 0)),
             ),
             Check::new(
                 CheckKind::UnusedVariable("x".to_string()),
-                Range {
-                    location: Location::new(1, 0),
-                    end_location: Location::new(1, 0),
-                },
+                Range::new(Location::new(1, 0), Location::new(1, 0)),
             ),
         ];
         let contents = "x = 1  # noqa: E741\n";
@@ -298,17 +289,11 @@ mod tests {
         let checks = vec![
             Check::new(
                 CheckKind::AmbiguousVariableName("x".to_string()),
-                Range {
-                    location: Location::new(1, 0),
-                    end_location: Location::new(1, 0),
-                },
+                Range::new(Location::new(1, 0), Location::new(1, 0)),
             ),
             Check::new(
                 CheckKind::UnusedVariable("x".to_string()),
-                Range {
-                    location: Location::new(1, 0),
-                    end_location: Location::new(1, 0),
-                },
+                Range::new(Location::new(1, 0), Location::new(1, 0)),
             ),
         ];
         let contents = "x = 1  # noqa";

src/pycodestyle/checks.rs

@@ -34,10 +34,10 @@ pub fn line_too_long(lineno: usize, line: &str, max_line_length: usize) -> Optio
 
     Some(Check::new(
         CheckKind::LineTooLong(line_length, max_line_length),
-        Range {
-            location: Location::new(lineno + 1, max_line_length),
-            end_location: Location::new(lineno + 1, line_length),
-        },
+        Range::new(
+            Location::new(lineno + 1, max_line_length),
+            Location::new(lineno + 1, line_length),
+        ),
     ))
 }
 
@@ -162,10 +162,7 @@ pub fn no_newline_at_end_of_file(contents: &str, autofix: bool) -> Option<Check>
             let location = Location::new(contents.lines().count(), line.len());
             let mut check = Check::new(
                 CheckKind::NoNewLineAtEndOfFile,
-                Range {
-                    location,
-                    end_location: location,
-                },
+                Range::new(location, location),
             );
             if autofix {
                 check.amend(Fix::insertion("\n".to_string(), location));
@@ -203,10 +200,7 @@ pub fn invalid_escape_sequence(
 ) -> Vec<Check> {
     let mut checks = vec![];
 
-    let text = locator.slice_source_code_range(&Range {
-        location: start,
-        end_location: end,
-    });
+    let text = locator.slice_source_code_range(&Range::new(start, end));
 
     // Determine whether the string is single- or triple-quoted.
     let quote = extract_quote(&text);
@@ -249,10 +243,7 @@ pub fn invalid_escape_sequence(
                 let end_location = Location::new(location.row(), location.column() + 2);
                 let mut check = Check::new(
                     CheckKind::InvalidEscapeSequence(next_char),
-                    Range {
-                        location,
-                        end_location,
-                    },
+                    Range::new(location, end_location),
                 );
                 if autofix {
                     check.amend(Fix::insertion(r"\".to_string(), location));

src/pycodestyle/plugins.rs

@@ -329,10 +329,10 @@ pub fn do_not_assign_lambda(checker: &mut Checker, target: &Expr, value: &Expr,
                 {
                     match function(id, args, body, checker.style) {
                         Ok(content) => {
-                            let first_line = checker.locator.slice_source_code_range(&Range {
-                                location: Location::new(stmt.location.row(), 0),
-                                end_location: Location::new(stmt.location.row() + 1, 0),
-                            });
+                            let first_line = checker.locator.slice_source_code_range(&Range::new(
+                                Location::new(stmt.location.row(), 0),
+                                Location::new(stmt.location.row() + 1, 0),
+                            ));
                             let indentation = &leading_space(&first_line);
                             let mut indented = String::new();
                             for (idx, line) in content.lines().enumerate() {

src/pycodestyle/snapshots/ruff__pycodestyle__tests__E741_E741.py.snap

@@ -249,7 +249,7 @@ expression: checks
     column: 4
   end_location:
     row: 74
-    column: 10
+    column: 5
   fix: ~
   parent: ~
 

src/pydocstyle/plugins.rs

@@ -34,10 +34,7 @@ pub fn not_missing(
             if checker.settings.enabled.contains(&CheckCode::D100) {
                 checker.add_check(Check::new(
                     CheckKind::PublicModule,
-                    Range {
-                        location: Location::new(1, 0),
-                        end_location: Location::new(1, 0),
-                    },
+                    Range::new(Location::new(1, 0), Location::new(1, 0)),
                 ));
             }
             false
@@ -46,10 +43,7 @@ pub fn not_missing(
             if checker.settings.enabled.contains(&CheckCode::D104) {
                 checker.add_check(Check::new(
                     CheckKind::PublicPackage,
-                    Range {
-                        location: Location::new(1, 0),
-                        end_location: Location::new(1, 0),
-                    },
+                    Range::new(Location::new(1, 0), Location::new(1, 0)),
                 ));
             }
             false
@@ -412,10 +406,10 @@ pub fn indent(checker: &mut Checker, docstring: &Docstring) {
             {
                 let mut check = Check::new(
                     CheckKind::NoUnderIndentation,
-                    Range {
-                        location: Location::new(docstring.expr.location.row() + i, 0),
-                        end_location: Location::new(docstring.expr.location.row() + i, 0),
-                    },
+                    Range::new(
+                        Location::new(docstring.expr.location.row() + i, 0),
+                        Location::new(docstring.expr.location.row() + i, 0),
+                    ),
                 );
                 if checker.patch(check.kind.code()) {
                     check.amend(Fix::replacement(
@@ -462,10 +456,10 @@ pub fn indent(checker: &mut Checker, docstring: &Docstring) {
                     // enables autofix.
                     let mut check = Check::new(
                         CheckKind::NoOverIndentation,
-                        Range {
-                            location: Location::new(docstring.expr.location.row() + i, 0),
-                            end_location: Location::new(docstring.expr.location.row() + i, 0),
-                        },
+                        Range::new(
+                            Location::new(docstring.expr.location.row() + i, 0),
+                            Location::new(docstring.expr.location.row() + i, 0),
+                        ),
                     );
                     if checker.patch(check.kind.code()) {
                         check.amend(Fix::replacement(
@@ -486,10 +480,10 @@ pub fn indent(checker: &mut Checker, docstring: &Docstring) {
             if line_indent.len() > docstring.indentation.len() {
                 let mut check = Check::new(
                     CheckKind::NoOverIndentation,
-                    Range {
-                        location: Location::new(docstring.expr.location.row() + i, 0),
-                        end_location: Location::new(docstring.expr.location.row() + i, 0),
-                    },
+                    Range::new(
+                        Location::new(docstring.expr.location.row() + i, 0),
+                        Location::new(docstring.expr.location.row() + i, 0),
+                    ),
                 );
                 if checker.patch(check.kind.code()) {
                     check.amend(Fix::replacement(
@@ -671,9 +665,35 @@ pub fn ends_with_period(checker: &mut Checker, docstring: &Docstring) {
     let contents = docstring.contents;
     let body = docstring.body;
 
+    if let Some(first_line) = body.trim().lines().next() {
+        let trimmed = first_line.trim();
+
+        // Avoid false-positives: `:param`, etc.
+        for prefix in [":param", ":type", ":raises", ":return", ":rtype"] {
+            if trimmed.starts_with(prefix) {
+                return;
+            }
+        }
+
+        // Avoid false-positives: `Args:`, etc.
+        for style in [SectionStyle::Google, SectionStyle::Numpy] {
+            for section_name in style.section_names().iter() {
+                if let Some(suffix) = trimmed.strip_suffix(section_name) {
+                    if suffix.is_empty() {
+                        return;
+                    }
+                    if suffix == ":" {
+                        return;
+                    }
+                }
+            }
+        }
+    }
+
     if let Some(index) = logical_line(body) {
         let line = body.lines().nth(index).unwrap();
         let trimmed = line.trim_end();
+
         if !trimmed.ends_with('.') {
             let mut check =
                 Check::new(CheckKind::EndsInPeriod, Range::from_located(docstring.expr));
@@ -718,7 +738,7 @@ pub fn no_signature(checker: &mut Checker, docstring: &Docstring) {
 
     let body = docstring.body;
 
-    let Some(first_line) = body.lines().next() else {
+    let Some(first_line) = body.trim().lines().next() else {
         return;
     };
     if !first_line.contains(&format!("{name}(")) {
@@ -791,6 +811,31 @@ pub fn ends_with_punctuation(checker: &mut Checker, docstring: &Docstring) {
     let contents = docstring.contents;
     let body = docstring.body;
 
+    if let Some(first_line) = body.trim().lines().next() {
+        let trimmed = first_line.trim();
+
+        // Avoid false-positives: `:param`, etc.
+        for prefix in [":param", ":type", ":raises", ":return", ":rtype"] {
+            if trimmed.starts_with(prefix) {
+                return;
+            }
+        }
+
+        // Avoid false-positives: `Args:`, etc.
+        for style in [SectionStyle::Google, SectionStyle::Numpy] {
+            for section_name in style.section_names().iter() {
+                if let Some(suffix) = trimmed.strip_suffix(section_name) {
+                    if suffix.is_empty() {
+                        return;
+                    }
+                    if suffix == ":" {
+                        return;
+                    }
+                }
+            }
+        }
+    }
+
     if let Some(index) = logical_line(body) {
         let line = body.lines().nth(index).unwrap();
         let trimmed = line.trim_end();
@@ -875,14 +920,14 @@ pub fn sections(checker: &mut Checker, docstring: &Docstring, convention: Option
             }
         }
         Some(Convention::Numpy) => {
-            for context in &section_contexts(&lines, &SectionStyle::NumPy) {
+            for context in &section_contexts(&lines, &SectionStyle::Numpy) {
                 numpy_section(checker, docstring, context);
             }
         }
         None => {
             // First, interpret as NumPy-style sections.
             let mut found_numpy_section = false;
-            for context in &section_contexts(&lines, &SectionStyle::NumPy) {
+            for context in &section_contexts(&lines, &SectionStyle::Numpy) {
                 found_numpy_section = true;
                 numpy_section(checker, docstring, context);
             }
@@ -1424,7 +1469,7 @@ fn parameters_section(checker: &mut Checker, docstring: &Docstring, context: &Se
 }
 
 fn numpy_section(checker: &mut Checker, docstring: &Docstring, context: &SectionContext) {
-    common_section(checker, docstring, context, &SectionStyle::NumPy);
+    common_section(checker, docstring, context, &SectionStyle::Numpy);
 
     if checker.settings.enabled.contains(&CheckCode::D406) {
         let suffix = context

src/pydocstyle/snapshots/ruff__pydocstyle__tests__D400_D400.py.snap

@@ -100,98 +100,98 @@ expression: checks
   parent: ~
 - kind: EndsInPeriod
   location:
-    row: 40
+    row: 39
     column: 4
   end_location:
-    row: 40
+    row: 39
     column: 37
   fix:
     content: "."
     location:
-      row: 40
+      row: 39
       column: 36
     end_location:
-      row: 40
+      row: 39
       column: 36
   parent: ~
 - kind: EndsInPeriod
   location:
-    row: 45
+    row: 44
     column: 4
   end_location:
-    row: 45
+    row: 44
     column: 41
   fix:
     content: "."
     location:
-      row: 45
+      row: 44
       column: 38
     end_location:
-      row: 45
+      row: 44
       column: 38
   parent: ~
 - kind: EndsInPeriod
   location:
-    row: 50
+    row: 49
     column: 4
   end_location:
-    row: 53
+    row: 52
     column: 7
   fix:
     content: "."
     location:
-      row: 52
+      row: 51
       column: 28
     end_location:
-      row: 52
+      row: 51
       column: 28
   parent: ~
 - kind: EndsInPeriod
   location:
-    row: 58
+    row: 57
     column: 4
   end_location:
-    row: 58
+    row: 57
     column: 41
   fix:
     content: "."
     location:
-      row: 58
+      row: 57
       column: 38
     end_location:
-      row: 58
+      row: 57
       column: 38
   parent: ~
 - kind: EndsInPeriod
   location:
-    row: 63
+    row: 62
     column: 4
   end_location:
-    row: 65
+    row: 64
     column: 31
   fix:
     content: "."
     location:
-      row: 65
+      row: 64
       column: 28
     end_location:
-      row: 65
+      row: 64
       column: 28
   parent: ~
 - kind: EndsInPeriod
   location:
-    row: 70
+    row: 69
     column: 4
   end_location:
-    row: 72
+    row: 71
     column: 52
   fix:
     content: "."
     location:
-      row: 72
+      row: 71
       column: 48
     end_location:
-      row: 72
+      row: 71
       column: 48
   parent: ~
 

src/pyflakes/snapshots/ruff__pyflakes__tests__F541_F541.py.snap

@@ -38,4 +38,22 @@ expression: checks
     column: 16
   fix: ~
   parent: ~
+- kind: FStringMissingPlaceholders
+  location:
+    row: 26
+    column: 6
+  end_location:
+    row: 26
+    column: 13
+  fix: ~
+  parent: ~
+- kind: FStringMissingPlaceholders
+  location:
+    row: 27
+    column: 3
+  end_location:
+    row: 27
+    column: 6
+  fix: ~
+  parent: ~
 

src/pyflakes/snapshots/ruff__pyflakes__tests__F821_F821_0.py.snap

@@ -82,33 +82,53 @@ expression: checks
     column: 8
   fix: ~
   parent: ~
+- kind:
+    UndefinedName: B
+  location:
+    row: 92
+    column: 10
+  end_location:
+    row: 92
+    column: 11
+  fix: ~
+  parent: ~
+- kind:
+    UndefinedName: B
+  location:
+    row: 93
+    column: 13
+  end_location:
+    row: 93
+    column: 14
+  fix: ~
+  parent: ~
 - kind:
     UndefinedName: PEP593Test123
   location:
-    row: 114
+    row: 115
     column: 8
   end_location:
-    row: 114
+    row: 115
     column: 23
   fix: ~
   parent: ~
 - kind:
     UndefinedName: foo
   location:
-    row: 122
+    row: 123
     column: 13
   end_location:
-    row: 122
+    row: 123
     column: 18
   fix: ~
   parent: ~
 - kind:
     UndefinedName: bar
   location:
-    row: 122
+    row: 123
     column: 20
   end_location:
-    row: 122
+    row: 123
     column: 25
   fix: ~
   parent: ~

src/pygrep_hooks/plugins/blanket_noqa.rs

@@ -13,10 +13,10 @@ pub fn blanket_noqa(lineno: usize, line: &str) -> Option<Check> {
     BLANKET_NOQA_REGEX.find(line).map(|m| {
         Check::new(
             CheckKind::BlanketNOQA,
-            Range {
-                location: Location::new(lineno + 1, m.start()),
-                end_location: Location::new(lineno + 1, m.end()),
-            },
+            Range::new(
+                Location::new(lineno + 1, m.start()),
+                Location::new(lineno + 1, m.end()),
+            ),
         )
     })
 }

src/pygrep_hooks/plugins/blanket_type_ignore.rs

@@ -13,10 +13,10 @@ pub fn blanket_type_ignore(lineno: usize, line: &str) -> Option<Check> {
     BLANKET_TYPE_IGNORE_REGEX.find(line).map(|m| {
         Check::new(
             CheckKind::BlanketTypeIgnore,
-            Range {
-                location: Location::new(lineno + 1, m.start()),
-                end_location: Location::new(lineno + 1, m.end()),
-            },
+            Range::new(
+                Location::new(lineno + 1, m.start()),
+                Location::new(lineno + 1, m.end()),
+            ),
         )
     })
 }

src/pyupgrade/checks.rs

@@ -170,10 +170,7 @@ pub fn unnecessary_coding_comment(lineno: usize, line: &str, autofix: bool) -> O
     if CODING_COMMENT_REGEX.is_match(line) {
         let mut check = Check::new(
             CheckKind::PEP3120UnnecessaryCodingComment,
-            Range {
-                location: Location::new(lineno + 1, 0),
-                end_location: Location::new(lineno + 2, 0),
-            },
+            Range::new(Location::new(lineno + 1, 0), Location::new(lineno + 2, 0)),
         );
         if autofix {
             check.amend(Fix::deletion(
@@ -216,10 +213,7 @@ pub fn unnecessary_lru_cache_params(
             continue;
         }
 
-        let range = Range {
-            location: func.end_location.unwrap(),
-            end_location: expr.end_location.unwrap(),
-        };
+        let range = Range::new(func.end_location.unwrap(), expr.end_location.unwrap());
         // Ex) `functools.lru_cache()`
         if keywords.is_empty() {
             return Some(Check::new(CheckKind::UnnecessaryLRUCacheParams, range));

src/pyupgrade/mod.rs

@@ -42,7 +42,11 @@ mod tests {
     #[test_case(CheckCode::UP021, Path::new("UP021.py"); "UP021")]
     #[test_case(CheckCode::UP022, Path::new("UP022.py"); "UP022")]
     #[test_case(CheckCode::UP023, Path::new("UP023.py"); "UP023")]
+    #[test_case(CheckCode::UP024, Path::new("UP024_0.py"); "UP024_0")]
+    #[test_case(CheckCode::UP024, Path::new("UP024_1.py"); "UP024_1")]
+    #[test_case(CheckCode::UP024, Path::new("UP024_2.py"); "UP024_2")]
     #[test_case(CheckCode::UP025, Path::new("UP025.py"); "UP025")]
+    #[test_case(CheckCode::UP026, Path::new("UP026.py"); "UP026")]
     fn checks(check_code: CheckCode, path: &Path) -> Result<()> {
         let snapshot = format!("{}_{}", check_code.as_ref(), path.to_string_lossy());
         let checks = test_path(

src/pyupgrade/plugins/mod.rs

@@ -4,11 +4,13 @@ pub use datetime_utc_alias::datetime_utc_alias;
 pub use deprecated_unittest_alias::deprecated_unittest_alias;
 pub use native_literals::native_literals;
 pub use open_alias::open_alias;
+pub use os_error_alias::os_error_alias;
 pub use redundant_open_modes::redundant_open_modes;
 pub use remove_six_compat::remove_six_compat;
 pub use replace_stdout_stderr::replace_stdout_stderr;
 pub use replace_universal_newlines::replace_universal_newlines;
 pub use rewrite_c_element_tree::replace_c_element_tree;
+pub use rewrite_mock_import::{rewrite_mock_attribute, rewrite_mock_import};
 pub use rewrite_unicode_literal::rewrite_unicode_literal;
 pub use super_call_with_parameters::super_call_with_parameters;
 pub use type_of_primitive::type_of_primitive;
@@ -27,11 +29,13 @@ mod datetime_utc_alias;
 mod deprecated_unittest_alias;
 mod native_literals;
 mod open_alias;
+mod os_error_alias;
 mod redundant_open_modes;
 mod remove_six_compat;
 mod replace_stdout_stderr;
 mod replace_universal_newlines;
 mod rewrite_c_element_tree;
+mod rewrite_mock_import;
 mod rewrite_unicode_literal;
 mod super_call_with_parameters;
 mod type_of_primitive;

src/pyupgrade/plugins/os_error_alias.rs

@@ -0,0 +1,236 @@
+#![allow(clippy::len_zero, clippy::needless_pass_by_value)]
+
+use itertools::Itertools;
+use rustpython_ast::{Excepthandler, ExcepthandlerKind, Expr, ExprKind, Located};
+
+use crate::ast::helpers::{compose_call_path, match_module_member};
+use crate::ast::types::Range;
+use crate::autofix::Fix;
+use crate::checkers::ast::Checker;
+use crate::checks::{Check, CheckKind};
+
+const ERROR_NAMES: &[&str] = &["EnvironmentError", "IOError", "WindowsError"];
+const ERROR_MODULES: &[&str] = &["mmap", "select", "socket"];
+
+fn get_correct_name(original: &str) -> String {
+    if ERROR_NAMES.contains(&original) {
+        "OSError".to_string()
+    } else {
+        original.to_string()
+    }
+}
+
+fn get_before_replace(elts: &[Expr]) -> Vec<String> {
+    elts.iter()
+        .map(|elt| {
+            if let ExprKind::Name { id, .. } = &elt.node {
+                id.to_string()
+            } else {
+                String::new()
+            }
+        })
+        .collect()
+}
+
+fn check_module(checker: &Checker, expr: &Expr) -> (Vec<String>, Vec<String>) {
+    let mut replacements: Vec<String> = vec![];
+    let mut before_replace: Vec<String> = vec![];
+    for module in ERROR_MODULES.iter() {
+        if match_module_member(
+            expr,
+            module,
+            "error",
+            &checker.from_imports,
+            &checker.import_aliases,
+        ) {
+            replacements.push("OSError".to_string());
+            before_replace.push(format!("{module}.error"));
+            break;
+        }
+    }
+    (replacements, before_replace)
+}
+
+fn handle_name_or_attribute(
+    checker: &Checker,
+    item: &Expr,
+    replacements: &mut Vec<String>,
+    before_replace: &mut Vec<String>,
+) {
+    match &item.node {
+        ExprKind::Name { id, .. } => {
+            let (temp_replacements, temp_before_replace) = check_module(checker, item);
+            replacements.extend(temp_replacements);
+            before_replace.extend(temp_before_replace);
+            if replacements.is_empty() {
+                let new_name = get_correct_name(id);
+                replacements.push(new_name);
+                before_replace.push(id.to_string());
+            }
+        }
+        ExprKind::Attribute { .. } => {
+            let (temp_replacements, temp_before_replace) = check_module(checker, item);
+            replacements.extend(temp_replacements);
+            before_replace.extend(temp_before_replace);
+        }
+        _ => (),
+    }
+}
+
+/// Handles one block of an except (use a loop if there are multile blocks)
+fn handle_except_block(checker: &mut Checker, handler: &Located<ExcepthandlerKind>) {
+    let ExcepthandlerKind::ExceptHandler { type_, .. } = &handler.node;
+    let Some(error_handlers) = type_.as_ref() else {
+        return;
+    };
+    // The first part creates list of all the exceptions being caught, and
+    // what they should be changed to
+    let mut replacements: Vec<String> = vec![];
+    let mut before_replace: Vec<String> = vec![];
+    match &error_handlers.node {
+        ExprKind::Name { .. } | ExprKind::Attribute { .. } => {
+            handle_name_or_attribute(
+                checker,
+                error_handlers,
+                &mut replacements,
+                &mut before_replace,
+            );
+        }
+        ExprKind::Tuple { elts, .. } => {
+            before_replace = get_before_replace(elts);
+            for elt in elts {
+                match &elt.node {
+                    ExprKind::Name { id, .. } => {
+                        let new_name = get_correct_name(id);
+                        replacements.push(new_name);
+                    }
+                    ExprKind::Attribute { .. } => {
+                        let (new_replacements, new_before_replace) = check_module(checker, elt);
+                        replacements.extend(new_replacements);
+                        before_replace.extend(new_before_replace);
+                    }
+                    _ => (),
+                }
+            }
+        }
+        _ => return,
+    }
+    replacements = replacements
+        .iter()
+        .unique()
+        .map(std::string::ToString::to_string)
+        .collect();
+    before_replace = before_replace
+        .iter()
+        .filter(|x| !x.is_empty())
+        .map(std::string::ToString::to_string)
+        .collect();
+
+    // This part checks if there are differences between what there is and
+    // what there should be. Where differences, the changes are applied
+    handle_making_changes(checker, error_handlers, &before_replace, &replacements);
+}
+
+fn handle_making_changes(
+    checker: &mut Checker,
+    target: &Expr,
+    before_replace: &[String],
+    replacements: &[String],
+) {
+    if before_replace != replacements && replacements.len() > 0 {
+        let range = Range::new(target.location, target.end_location.unwrap());
+        let contents = checker.locator.slice_source_code_range(&range);
+        // Pyyupgrade does not want imports changed if a module only is
+        // surrounded by parentheses. For example: `except mmap.error:`
+        // would be changed, but: `(mmap).error:` would not. One issue with
+        // this implementation is that any valid changes will also be
+        // ignored. Let me know if you want me to go with a more
+        // complicated solution that avoids this.
+        if contents.contains(").") {
+            return;
+        }
+        let mut final_str: String;
+        if replacements.len() == 1 {
+            final_str = replacements.get(0).unwrap().to_string();
+        } else {
+            final_str = replacements.join(", ");
+            final_str.insert(0, '(');
+            final_str.push(')');
+        }
+        let mut check = Check::new(CheckKind::OSErrorAlias(compose_call_path(target)), range);
+        if checker.patch(check.kind.code()) {
+            check.amend(Fix::replacement(
+                final_str,
+                range.location,
+                range.end_location,
+            ));
+        }
+        checker.add_check(check);
+    }
+}
+
+// This is a hacky way to handle the different variable types we get since
+// raise and try are very different. Would love input on a cleaner way
+pub trait OSErrorAliasChecker {
+    fn check_error(&self, checker: &mut Checker)
+    where
+        Self: Sized;
+}
+
+impl OSErrorAliasChecker for &Vec<Excepthandler> {
+    fn check_error(&self, checker: &mut Checker) {
+        // Each separate except block is a separate error and fix
+        for handler in self.iter() {
+            handle_except_block(checker, handler);
+        }
+    }
+}
+
+impl OSErrorAliasChecker for &Box<Expr> {
+    fn check_error(&self, checker: &mut Checker) {
+        let mut replacements: Vec<String> = vec![];
+        let mut before_replace: Vec<String> = vec![];
+        match &self.node {
+            ExprKind::Name { .. } | ExprKind::Attribute { .. } => {
+                handle_name_or_attribute(checker, self, &mut replacements, &mut before_replace);
+            }
+            _ => return,
+        }
+        handle_making_changes(checker, self, &before_replace, &replacements);
+    }
+}
+
+impl OSErrorAliasChecker for &Expr {
+    fn check_error(&self, checker: &mut Checker) {
+        let mut replacements: Vec<String> = vec![];
+        let mut before_replace: Vec<String> = vec![];
+        let change_target: &Expr;
+        match &self.node {
+            ExprKind::Name { .. } | ExprKind::Attribute { .. } => {
+                change_target = self;
+                handle_name_or_attribute(checker, self, &mut replacements, &mut before_replace);
+            }
+            ExprKind::Call { func, .. } => {
+                change_target = func;
+                match &func.node {
+                    ExprKind::Name { .. } | ExprKind::Attribute { .. } => {
+                        handle_name_or_attribute(
+                            checker,
+                            func,
+                            &mut replacements,
+                            &mut before_replace,
+                        );
+                    }
+                    _ => return,
+                }
+            }
+            _ => return,
+        }
+        handle_making_changes(checker, change_target, &before_replace, &replacements);
+    }
+}
+
+/// UP024
+pub fn os_error_alias<U: OSErrorAliasChecker>(checker: &mut Checker, handlers: U) {
+    handlers.check_error(checker);
+}

src/pyupgrade/plugins/redundant_open_modes.rs

@@ -107,10 +107,8 @@ fn create_remove_param_fix(
     expr: &Expr,
     mode_param: &Expr,
 ) -> Result<Fix> {
-    let content = locator.slice_source_code_range(&Range {
-        location: expr.location,
-        end_location: expr.end_location.unwrap(),
-    });
+    let content =
+        locator.slice_source_code_range(&Range::new(expr.location, expr.end_location.unwrap()));
     // Find the last comma before mode_param and create a deletion fix
     // starting from the comma and ending after mode_param.
     let mut fix_start: Option<Location> = None;

src/pyupgrade/plugins/remove_six_compat.rs

@@ -65,10 +65,10 @@ fn replace_by_str_literal(
                 let content = format!(
                     "{}{}",
                     if binary { "b" } else { "" },
-                    locator.slice_source_code_range(&Range {
-                        location: arg.location,
-                        end_location: arg.end_location.unwrap(),
-                    })
+                    locator.slice_source_code_range(&Range::new(
+                        arg.location,
+                        arg.end_location.unwrap(),
+                    ))
                 );
                 check.amend(Fix::replacement(
                     content,

src/pyupgrade/plugins/replace_stdout_stderr.rs

@@ -87,10 +87,12 @@ pub fn replace_stdout_stderr(checker: &mut Checker, expr: &Expr, kwargs: &[Keywo
                 stderr
             };
             let mut contents = String::from("capture_output=True");
-            if let Some(middle) = extract_middle(&checker.locator.slice_source_code_range(&Range {
-                location: first.end_location.unwrap(),
-                end_location: last.location,
-            })) {
+            if let Some(middle) =
+                extract_middle(&checker.locator.slice_source_code_range(&Range::new(
+                    first.end_location.unwrap(),
+                    last.location,
+                )))
+            {
                 if middle.multi_line {
                     contents.push(',');
                     contents.push('\n');

src/pyupgrade/plugins/replace_universal_newlines.rs

@@ -16,13 +16,13 @@ pub fn replace_universal_newlines(checker: &mut Checker, expr: &Expr, kwargs: &[
         &checker.import_aliases,
     ) {
         let Some(kwarg) = find_keyword(kwargs, "universal_newlines") else { return; };
-        let range = Range {
-            location: kwarg.location,
-            end_location: Location::new(
+        let range = Range::new(
+            kwarg.location,
+            Location::new(
                 kwarg.location.row(),
                 kwarg.location.column() + "universal_newlines".len(),
             ),
-        };
+        );
         let mut check = Check::new(CheckKind::ReplaceUniversalNewlines, range);
         if checker.patch(check.kind.code()) {
             check.amend(Fix::replacement(

src/pyupgrade/plugins/rewrite_mock_import.rs

@@ -0,0 +1,275 @@
+use anyhow::Result;
+use libcst_native::{
+    AsName, AssignTargetExpression, Attribute, Codegen, CodegenState, Dot, Expression, Import,
+    ImportAlias, ImportFrom, ImportNames, Name, NameOrAttribute, ParenthesizableWhitespace,
+};
+use log::error;
+use rustpython_ast::{Expr, ExprKind, Stmt, StmtKind};
+
+use crate::ast::helpers::collect_call_paths;
+use crate::ast::types::Range;
+use crate::ast::whitespace::indentation;
+use crate::autofix::Fix;
+use crate::checkers::ast::Checker;
+use crate::checks::{Check, CheckCode, CheckKind, MockReference};
+use crate::cst::matchers::{match_import, match_import_from, match_module};
+use crate::source_code_locator::SourceCodeLocator;
+use crate::source_code_style::SourceCodeStyleDetector;
+
+/// Return a vector of all non-`mock` imports.
+fn clean_import_aliases(aliases: Vec<ImportAlias>) -> (Vec<ImportAlias>, Vec<Option<AsName>>) {
+    let mut clean_aliases: Vec<ImportAlias> = vec![];
+    let mut mock_aliases: Vec<Option<AsName>> = vec![];
+    for alias in aliases {
+        match &alias.name {
+            // Ex) `import mock`
+            NameOrAttribute::N(name_struct) => {
+                if name_struct.value == "mock" {
+                    mock_aliases.push(alias.asname.clone());
+                    continue;
+                }
+                clean_aliases.push(alias);
+            }
+            // Ex) `import mock.mock`
+            NameOrAttribute::A(attribute_struct) => {
+                if let Expression::Name(name_struct) = &*attribute_struct.value {
+                    if name_struct.value == "mock" && attribute_struct.attr.value == "mock" {
+                        mock_aliases.push(alias.asname.clone());
+                        continue;
+                    }
+                }
+                clean_aliases.push(alias);
+            }
+        }
+    }
+    (clean_aliases, mock_aliases)
+}
+
+/// Return `true` if the aliases contain `mock`.
+fn includes_mock_member(aliases: &[ImportAlias]) -> bool {
+    for alias in aliases {
+        let ImportAlias { name, .. } = &alias;
+        // Ex) `import mock.mock`
+        if let NameOrAttribute::A(attribute_struct) = name {
+            if let Expression::Name(name_struct) = &*attribute_struct.value {
+                if name_struct.value == "mock" && attribute_struct.attr.value == "mock" {
+                    return true;
+                }
+            }
+        }
+    }
+    false
+}
+
+fn format_mocks(
+    aliases: Vec<Option<AsName>>,
+    indent: &str,
+    stylist: &SourceCodeStyleDetector,
+) -> String {
+    let mut content = String::new();
+    for alias in aliases {
+        match alias {
+            None => {
+                if !content.is_empty() {
+                    content.push_str(stylist.line_ending());
+                    content.push_str(indent);
+                }
+                content.push_str("from unittest import mock");
+            }
+            Some(as_name) => {
+                if let AssignTargetExpression::Name(name) = as_name.name {
+                    if !content.is_empty() {
+                        content.push_str(stylist.line_ending());
+                        content.push_str(indent);
+                    }
+                    content.push_str("from unittest import mock as ");
+                    content.push_str(name.value);
+                }
+            }
+        }
+    }
+    content
+}
+
+/// Format the `import mock` rewrite.
+fn format_import(
+    stmt: &Stmt,
+    indent: &str,
+    locator: &SourceCodeLocator,
+    stylist: &SourceCodeStyleDetector,
+) -> Result<String> {
+    let module_text = locator.slice_source_code_range(&Range::from_located(stmt));
+    let mut tree = match_module(&module_text)?;
+    let mut import = match_import(&mut tree)?;
+
+    let Import { names, .. } = import.clone();
+    let (clean_aliases, mock_aliases) = clean_import_aliases(names);
+
+    Ok(if clean_aliases.is_empty() {
+        format_mocks(mock_aliases, indent, stylist)
+    } else {
+        import.names = clean_aliases;
+
+        let mut state = CodegenState::default();
+        tree.codegen(&mut state);
+
+        let mut content = state.to_string();
+        content.push_str(stylist.line_ending());
+        content.push_str(indent);
+        content.push_str(&format_mocks(mock_aliases, indent, stylist));
+        content
+    })
+}
+
+/// Format the `from mock import ...` rewrite.
+fn format_import_from(
+    stmt: &Stmt,
+    indent: &str,
+    locator: &SourceCodeLocator,
+    stylist: &SourceCodeStyleDetector,
+) -> Result<String> {
+    let module_text = locator.slice_source_code_range(&Range::from_located(stmt));
+    let mut tree = match_module(&module_text).unwrap();
+    let mut import = match_import_from(&mut tree)?;
+
+    let ImportFrom {
+        names: ImportNames::Aliases(names),
+        ..
+    } = import.clone() else {
+        unreachable!("Expected ImportNames::Aliases");
+    };
+
+    let has_mock_member = includes_mock_member(&names);
+    let (clean_aliases, mock_aliases) = clean_import_aliases(names);
+
+    Ok(if clean_aliases.is_empty() {
+        format_mocks(mock_aliases, indent, stylist)
+    } else {
+        import.names = ImportNames::Aliases(clean_aliases);
+        import.module = Some(NameOrAttribute::A(Box::new(Attribute {
+            value: Box::new(Expression::Name(Box::new(Name {
+                value: "unittest",
+                lpar: vec![],
+                rpar: vec![],
+            }))),
+            attr: Name {
+                value: "mock",
+                lpar: vec![],
+                rpar: vec![],
+            },
+            dot: Dot {
+                whitespace_before: ParenthesizableWhitespace::default(),
+                whitespace_after: ParenthesizableWhitespace::default(),
+            },
+            lpar: vec![],
+            rpar: vec![],
+        })));
+
+        let mut state = CodegenState::default();
+        tree.codegen(&mut state);
+
+        let mut content = state.to_string();
+        if has_mock_member {
+            content.push_str(stylist.line_ending());
+            content.push_str(indent);
+            content.push_str(&format_mocks(mock_aliases, indent, stylist));
+        }
+        content
+    })
+}
+
+/// UP026
+pub fn rewrite_mock_attribute(checker: &mut Checker, expr: &Expr) {
+    if let ExprKind::Attribute { value, .. } = &expr.node {
+        if collect_call_paths(value) == ["mock", "mock"] {
+            let mut check = Check::new(
+                CheckKind::RewriteMockImport(MockReference::Attribute),
+                Range::from_located(value),
+            );
+            if checker.patch(&CheckCode::UP026) {
+                check.amend(Fix::replacement(
+                    "mock".to_string(),
+                    value.location,
+                    value.end_location.unwrap(),
+                ));
+            }
+            checker.add_check(check);
+        }
+    }
+}
+
+/// UP026
+pub fn rewrite_mock_import(checker: &mut Checker, stmt: &Stmt) {
+    match &stmt.node {
+        StmtKind::Import { names } => {
+            // Find all `mock` imports.
+            if names
+                .iter()
+                .any(|name| name.node.name == "mock" || name.node.name == "mock.mock")
+            {
+                // Generate the fix, if needed, which is shared between all `mock` imports.
+                let content = if checker.patch(&CheckCode::UP026) {
+                    let indent = indentation(checker, stmt);
+                    match format_import(stmt, &indent, checker.locator, checker.style) {
+                        Ok(content) => Some(content),
+                        Err(e) => {
+                            error!("Failed to rewrite `mock` import: {e}");
+                            None
+                        }
+                    }
+                } else {
+                    None
+                };
+
+                // Add a `Check` for each `mock` import.
+                for name in names {
+                    if name.node.name == "mock" || name.node.name == "mock.mock" {
+                        let mut check = Check::new(
+                            CheckKind::RewriteMockImport(MockReference::Import),
+                            Range::from_located(name),
+                        );
+                        if let Some(content) = content.as_ref() {
+                            check.amend(Fix::replacement(
+                                content.clone(),
+                                stmt.location,
+                                stmt.end_location.unwrap(),
+                            ));
+                        }
+                        checker.add_check(check);
+                    }
+                }
+            }
+        }
+        StmtKind::ImportFrom {
+            module: Some(module),
+            level,
+            ..
+        } => {
+            if level.map_or(false, |level| level > 0) {
+                return;
+            }
+
+            if module == "mock" {
+                let mut check = Check::new(
+                    CheckKind::RewriteMockImport(MockReference::Import),
+                    Range::from_located(stmt),
+                );
+                if checker.patch(&CheckCode::UP026) {
+                    let indent = indentation(checker, stmt);
+                    match format_import_from(stmt, &indent, checker.locator, checker.style) {
+                        Ok(content) => {
+                            check.amend(Fix::replacement(
+                                content,
+                                stmt.location,
+                                stmt.end_location.unwrap(),
+                            ));
+                        }
+                        Err(e) => error!("Failed to rewrite `mock` import: {e}"),
+                    }
+                }
+                checker.add_check(check);
+            }
+        }
+        _ => (),
+    }
+}

src/pyupgrade/plugins/unnecessary_encode_utf8.rs

@@ -84,10 +84,10 @@ fn replace_with_bytes_literal(
 ) -> Check {
     let mut check = Check::new(CheckKind::UnnecessaryEncodeUTF8, Range::from_located(expr));
     if patch {
-        let content = locator.slice_source_code_range(&Range {
-            location: constant.location,
-            end_location: constant.end_location.unwrap(),
-        });
+        let content = locator.slice_source_code_range(&Range::new(
+            constant.location,
+            constant.end_location.unwrap(),
+        ));
         let content = format!(
             "b{}",
             content.trim_start_matches('u').trim_start_matches('U')

src/pyupgrade/plugins/unnecessary_future_import.rs

@@ -80,7 +80,7 @@ pub fn unnecessary_future_import(checker: &mut Checker, stmt: &Stmt, names: &[Lo
                 }
                 check.amend(fix);
             }
-            Err(e) => error!("Failed to remove __future__ import: {e}"),
+            Err(e) => error!("Failed to remove `__future__` import: {e}"),
         }
     }
     checker.add_check(check);

src/pyupgrade/snapshots/ruff__pyupgrade__tests__UP024_UP024_0.py.snap

@@ -0,0 +1,209 @@
+---
+source: src/pyupgrade/mod.rs
+expression: checks
+---
+- kind:
+    OSErrorAlias: EnvironmentError
+  location:
+    row: 6
+    column: 7
+  end_location:
+    row: 6
+    column: 23
+  fix:
+    content: OSError
+    location:
+      row: 6
+      column: 7
+    end_location:
+      row: 6
+      column: 23
+  parent: ~
+- kind:
+    OSErrorAlias: IOError
+  location:
+    row: 11
+    column: 7
+  end_location:
+    row: 11
+    column: 14
+  fix:
+    content: OSError
+    location:
+      row: 11
+      column: 7
+    end_location:
+      row: 11
+      column: 14
+  parent: ~
+- kind:
+    OSErrorAlias: WindowsError
+  location:
+    row: 16
+    column: 7
+  end_location:
+    row: 16
+    column: 19
+  fix:
+    content: OSError
+    location:
+      row: 16
+      column: 7
+    end_location:
+      row: 16
+      column: 19
+  parent: ~
+- kind:
+    OSErrorAlias: mmap.error
+  location:
+    row: 21
+    column: 7
+  end_location:
+    row: 21
+    column: 17
+  fix:
+    content: OSError
+    location:
+      row: 21
+      column: 7
+    end_location:
+      row: 21
+      column: 17
+  parent: ~
+- kind:
+    OSErrorAlias: select.error
+  location:
+    row: 26
+    column: 7
+  end_location:
+    row: 26
+    column: 19
+  fix:
+    content: OSError
+    location:
+      row: 26
+      column: 7
+    end_location:
+      row: 26
+      column: 19
+  parent: ~
+- kind:
+    OSErrorAlias: socket.error
+  location:
+    row: 31
+    column: 7
+  end_location:
+    row: 31
+    column: 19
+  fix:
+    content: OSError
+    location:
+      row: 31
+      column: 7
+    end_location:
+      row: 31
+      column: 19
+  parent: ~
+- kind:
+    OSErrorAlias: error
+  location:
+    row: 36
+    column: 7
+  end_location:
+    row: 36
+    column: 12
+  fix:
+    content: OSError
+    location:
+      row: 36
+      column: 7
+    end_location:
+      row: 36
+      column: 12
+  parent: ~
+- kind:
+    OSErrorAlias: ~
+  location:
+    row: 43
+    column: 7
+  end_location:
+    row: 43
+    column: 17
+  fix:
+    content: OSError
+    location:
+      row: 43
+      column: 7
+    end_location:
+      row: 43
+      column: 17
+  parent: ~
+- kind:
+    OSErrorAlias: ~
+  location:
+    row: 47
+    column: 7
+  end_location:
+    row: 47
+    column: 20
+  fix:
+    content: OSError
+    location:
+      row: 47
+      column: 7
+    end_location:
+      row: 47
+      column: 20
+  parent: ~
+- kind:
+    OSErrorAlias: ~
+  location:
+    row: 51
+    column: 7
+  end_location:
+    row: 51
+    column: 57
+  fix:
+    content: OSError
+    location:
+      row: 51
+      column: 7
+    end_location:
+      row: 51
+      column: 57
+  parent: ~
+- kind:
+    OSErrorAlias: ~
+  location:
+    row: 58
+    column: 7
+  end_location:
+    row: 58
+    column: 35
+  fix:
+    content: "(OSError, KeyError)"
+    location:
+      row: 58
+      column: 7
+    end_location:
+      row: 58
+      column: 35
+  parent: ~
+- kind:
+    OSErrorAlias: ~
+  location:
+    row: 65
+    column: 7
+  end_location:
+    row: 65
+    column: 23
+  fix:
+    content: "(OSError, error)"
+    location:
+      row: 65
+      column: 7
+    end_location:
+      row: 65
+      column: 23
+  parent: ~
+

src/pyupgrade/snapshots/ruff__pyupgrade__tests__UP024_UP024_1.py.snap

@@ -0,0 +1,56 @@
+---
+source: src/pyupgrade/mod.rs
+expression: checks
+---
+- kind:
+    OSErrorAlias: ~
+  location:
+    row: 5
+    column: 7
+  end_location:
+    row: 5
+    column: 37
+  fix:
+    content: OSError
+    location:
+      row: 5
+      column: 7
+    end_location:
+      row: 5
+      column: 37
+  parent: ~
+- kind:
+    OSErrorAlias: ~
+  location:
+    row: 7
+    column: 7
+  end_location:
+    row: 7
+    column: 40
+  fix:
+    content: "(OSError, KeyError)"
+    location:
+      row: 7
+      column: 7
+    end_location:
+      row: 7
+      column: 40
+  parent: ~
+- kind:
+    OSErrorAlias: ~
+  location:
+    row: 12
+    column: 7
+  end_location:
+    row: 16
+    column: 1
+  fix:
+    content: OSError
+    location:
+      row: 12
+      column: 7
+    end_location:
+      row: 16
+      column: 1
+  parent: ~
+

src/pyupgrade/snapshots/ruff__pyupgrade__tests__UP024_UP024_2.py.snap

@@ -0,0 +1,345 @@
+---
+source: src/pyupgrade/mod.rs
+expression: checks
+---
+- kind:
+    OSErrorAlias: socket.error
+  location:
+    row: 10
+    column: 6
+  end_location:
+    row: 10
+    column: 18
+  fix:
+    content: OSError
+    location:
+      row: 10
+      column: 6
+    end_location:
+      row: 10
+      column: 18
+  parent: ~
+- kind:
+    OSErrorAlias: mmap.error
+  location:
+    row: 11
+    column: 6
+  end_location:
+    row: 11
+    column: 16
+  fix:
+    content: OSError
+    location:
+      row: 11
+      column: 6
+    end_location:
+      row: 11
+      column: 16
+  parent: ~
+- kind:
+    OSErrorAlias: select.error
+  location:
+    row: 12
+    column: 6
+  end_location:
+    row: 12
+    column: 18
+  fix:
+    content: OSError
+    location:
+      row: 12
+      column: 6
+    end_location:
+      row: 12
+      column: 18
+  parent: ~
+- kind:
+    OSErrorAlias: socket.error
+  location:
+    row: 14
+    column: 6
+  end_location:
+    row: 14
+    column: 18
+  fix:
+    content: OSError
+    location:
+      row: 14
+      column: 6
+    end_location:
+      row: 14
+      column: 18
+  parent: ~
+- kind:
+    OSErrorAlias: mmap.error
+  location:
+    row: 15
+    column: 6
+  end_location:
+    row: 15
+    column: 16
+  fix:
+    content: OSError
+    location:
+      row: 15
+      column: 6
+    end_location:
+      row: 15
+      column: 16
+  parent: ~
+- kind:
+    OSErrorAlias: select.error
+  location:
+    row: 16
+    column: 6
+  end_location:
+    row: 16
+    column: 18
+  fix:
+    content: OSError
+    location:
+      row: 16
+      column: 6
+    end_location:
+      row: 16
+      column: 18
+  parent: ~
+- kind:
+    OSErrorAlias: socket.error
+  location:
+    row: 18
+    column: 6
+  end_location:
+    row: 18
+    column: 18
+  fix:
+    content: OSError
+    location:
+      row: 18
+      column: 6
+    end_location:
+      row: 18
+      column: 18
+  parent: ~
+- kind:
+    OSErrorAlias: error
+  location:
+    row: 25
+    column: 6
+  end_location:
+    row: 25
+    column: 11
+  fix:
+    content: OSError
+    location:
+      row: 25
+      column: 6
+    end_location:
+      row: 25
+      column: 11
+  parent: ~
+- kind:
+    OSErrorAlias: error
+  location:
+    row: 28
+    column: 6
+  end_location:
+    row: 28
+    column: 11
+  fix:
+    content: OSError
+    location:
+      row: 28
+      column: 6
+    end_location:
+      row: 28
+      column: 11
+  parent: ~
+- kind:
+    OSErrorAlias: error
+  location:
+    row: 31
+    column: 6
+  end_location:
+    row: 31
+    column: 11
+  fix:
+    content: OSError
+    location:
+      row: 31
+      column: 6
+    end_location:
+      row: 31
+      column: 11
+  parent: ~
+- kind:
+    OSErrorAlias: EnvironmentError
+  location:
+    row: 34
+    column: 6
+  end_location:
+    row: 34
+    column: 22
+  fix:
+    content: OSError
+    location:
+      row: 34
+      column: 6
+    end_location:
+      row: 34
+      column: 22
+  parent: ~
+- kind:
+    OSErrorAlias: IOError
+  location:
+    row: 35
+    column: 6
+  end_location:
+    row: 35
+    column: 13
+  fix:
+    content: OSError
+    location:
+      row: 35
+      column: 6
+    end_location:
+      row: 35
+      column: 13
+  parent: ~
+- kind:
+    OSErrorAlias: WindowsError
+  location:
+    row: 36
+    column: 6
+  end_location:
+    row: 36
+    column: 18
+  fix:
+    content: OSError
+    location:
+      row: 36
+      column: 6
+    end_location:
+      row: 36
+      column: 18
+  parent: ~
+- kind:
+    OSErrorAlias: EnvironmentError
+  location:
+    row: 38
+    column: 6
+  end_location:
+    row: 38
+    column: 22
+  fix:
+    content: OSError
+    location:
+      row: 38
+      column: 6
+    end_location:
+      row: 38
+      column: 22
+  parent: ~
+- kind:
+    OSErrorAlias: IOError
+  location:
+    row: 39
+    column: 6
+  end_location:
+    row: 39
+    column: 13
+  fix:
+    content: OSError
+    location:
+      row: 39
+      column: 6
+    end_location:
+      row: 39
+      column: 13
+  parent: ~
+- kind:
+    OSErrorAlias: WindowsError
+  location:
+    row: 40
+    column: 6
+  end_location:
+    row: 40
+    column: 18
+  fix:
+    content: OSError
+    location:
+      row: 40
+      column: 6
+    end_location:
+      row: 40
+      column: 18
+  parent: ~
+- kind:
+    OSErrorAlias: EnvironmentError
+  location:
+    row: 42
+    column: 6
+  end_location:
+    row: 42
+    column: 22
+  fix:
+    content: OSError
+    location:
+      row: 42
+      column: 6
+    end_location:
+      row: 42
+      column: 22
+  parent: ~
+- kind:
+    OSErrorAlias: WindowsError
+  location:
+    row: 48
+    column: 6
+  end_location:
+    row: 48
+    column: 18
+  fix:
+    content: OSError
+    location:
+      row: 48
+      column: 6
+    end_location:
+      row: 48
+      column: 18
+  parent: ~
+- kind:
+    OSErrorAlias: EnvironmentError
+  location:
+    row: 49
+    column: 6
+  end_location:
+    row: 49
+    column: 22
+  fix:
+    content: OSError
+    location:
+      row: 49
+      column: 6
+    end_location:
+      row: 49
+      column: 22
+  parent: ~
+- kind:
+    OSErrorAlias: IOError
+  location:
+    row: 50
+    column: 6
+  end_location:
+    row: 50
+    column: 13
+  fix:
+    content: OSError
+    location:
+      row: 50
+      column: 6
+    end_location:
+      row: 50
+      column: 13
+  parent: ~
+

src/pyupgrade/snapshots/ruff__pyupgrade__tests__UP026_UP026.py.snap

@@ -0,0 +1,362 @@
+---
+source: src/pyupgrade/mod.rs
+expression: checks
+---
+- kind:
+    RewriteMockImport: Import
+  location:
+    row: 3
+    column: 11
+  end_location:
+    row: 3
+    column: 15
+  fix:
+    content: from unittest import mock
+    location:
+      row: 3
+      column: 4
+    end_location:
+      row: 3
+      column: 15
+  parent: ~
+- kind:
+    RewriteMockImport: Import
+  location:
+    row: 6
+    column: 11
+  end_location:
+    row: 6
+    column: 15
+  fix:
+    content: "import sys\n    from unittest import mock"
+    location:
+      row: 6
+      column: 4
+    end_location:
+      row: 6
+      column: 20
+  parent: ~
+- kind:
+    RewriteMockImport: Import
+  location:
+    row: 9
+    column: 7
+  end_location:
+    row: 9
+    column: 16
+  fix:
+    content: from unittest import mock
+    location:
+      row: 9
+      column: 0
+    end_location:
+      row: 9
+      column: 16
+  parent: ~
+- kind:
+    RewriteMockImport: Import
+  location:
+    row: 12
+    column: 19
+  end_location:
+    row: 12
+    column: 23
+  fix:
+    content: "import contextlib, sys\nfrom unittest import mock"
+    location:
+      row: 12
+      column: 0
+    end_location:
+      row: 12
+      column: 28
+  parent: ~
+- kind:
+    RewriteMockImport: Import
+  location:
+    row: 15
+    column: 7
+  end_location:
+    row: 15
+    column: 11
+  fix:
+    content: "import sys\nfrom unittest import mock"
+    location:
+      row: 15
+      column: 0
+    end_location:
+      row: 15
+      column: 16
+  parent: ~
+- kind:
+    RewriteMockImport: Import
+  location:
+    row: 19
+    column: 0
+  end_location:
+    row: 19
+    column: 21
+  fix:
+    content: from unittest import mock
+    location:
+      row: 19
+      column: 0
+    end_location:
+      row: 19
+      column: 21
+  parent: ~
+- kind:
+    RewriteMockImport: Import
+  location:
+    row: 22
+    column: 0
+  end_location:
+    row: 27
+    column: 1
+  fix:
+    content: "from unittest.mock import (\n    a,\n    b,\n    c,\n)"
+    location:
+      row: 22
+      column: 0
+    end_location:
+      row: 27
+      column: 1
+  parent: ~
+- kind:
+    RewriteMockImport: Import
+  location:
+    row: 30
+    column: 0
+  end_location:
+    row: 35
+    column: 1
+  fix:
+    content: "from unittest.mock import (\n    a,\n    b,\n    c\n)"
+    location:
+      row: 30
+      column: 0
+    end_location:
+      row: 35
+      column: 1
+  parent: ~
+- kind:
+    RewriteMockImport: Import
+  location:
+    row: 39
+    column: 8
+  end_location:
+    row: 44
+    column: 9
+  fix:
+    content: "from unittest.mock import (\n            a,\n            b,\n            c\n        )"
+    location:
+      row: 39
+      column: 8
+    end_location:
+      row: 44
+      column: 9
+  parent: ~
+- kind:
+    RewriteMockImport: Import
+  location:
+    row: 50
+    column: 7
+  end_location:
+    row: 50
+    column: 11
+  fix:
+    content: "from unittest import mock\nfrom unittest import mock"
+    location:
+      row: 50
+      column: 0
+    end_location:
+      row: 50
+      column: 17
+  parent: ~
+- kind:
+    RewriteMockImport: Import
+  location:
+    row: 50
+    column: 13
+  end_location:
+    row: 50
+    column: 17
+  fix:
+    content: "from unittest import mock\nfrom unittest import mock"
+    location:
+      row: 50
+      column: 0
+    end_location:
+      row: 50
+      column: 17
+  parent: ~
+- kind:
+    RewriteMockImport: Import
+  location:
+    row: 53
+    column: 7
+  end_location:
+    row: 53
+    column: 18
+  fix:
+    content: from unittest import mock as foo
+    location:
+      row: 53
+      column: 0
+    end_location:
+      row: 53
+      column: 18
+  parent: ~
+- kind:
+    RewriteMockImport: Import
+  location:
+    row: 56
+    column: 0
+  end_location:
+    row: 56
+    column: 28
+  fix:
+    content: from unittest import mock as foo
+    location:
+      row: 56
+      column: 0
+    end_location:
+      row: 56
+      column: 28
+  parent: ~
+- kind:
+    RewriteMockImport: Import
+  location:
+    row: 60
+    column: 11
+  end_location:
+    row: 60
+    column: 22
+  fix:
+    content: "from unittest import mock as foo\n    from unittest import mock as bar\n    from unittest import mock"
+    location:
+      row: 60
+      column: 4
+    end_location:
+      row: 60
+      column: 41
+  parent: ~
+- kind:
+    RewriteMockImport: Import
+  location:
+    row: 60
+    column: 24
+  end_location:
+    row: 60
+    column: 35
+  fix:
+    content: "from unittest import mock as foo\n    from unittest import mock as bar\n    from unittest import mock"
+    location:
+      row: 60
+      column: 4
+    end_location:
+      row: 60
+      column: 41
+  parent: ~
+- kind:
+    RewriteMockImport: Import
+  location:
+    row: 60
+    column: 37
+  end_location:
+    row: 60
+    column: 41
+  fix:
+    content: "from unittest import mock as foo\n    from unittest import mock as bar\n    from unittest import mock"
+    location:
+      row: 60
+      column: 4
+    end_location:
+      row: 60
+      column: 41
+  parent: ~
+- kind:
+    RewriteMockImport: Import
+  location:
+    row: 63
+    column: 11
+  end_location:
+    row: 63
+    column: 22
+  fix:
+    content: "import os\n    from unittest import mock as foo\n    from unittest import mock as bar\n    from unittest import mock"
+    location:
+      row: 63
+      column: 4
+    end_location:
+      row: 63
+      column: 45
+  parent: ~
+- kind:
+    RewriteMockImport: Import
+  location:
+    row: 63
+    column: 24
+  end_location:
+    row: 63
+    column: 35
+  fix:
+    content: "import os\n    from unittest import mock as foo\n    from unittest import mock as bar\n    from unittest import mock"
+    location:
+      row: 63
+      column: 4
+    end_location:
+      row: 63
+      column: 45
+  parent: ~
+- kind:
+    RewriteMockImport: Import
+  location:
+    row: 63
+    column: 37
+  end_location:
+    row: 63
+    column: 41
+  fix:
+    content: "import os\n    from unittest import mock as foo\n    from unittest import mock as bar\n    from unittest import mock"
+    location:
+      row: 63
+      column: 4
+    end_location:
+      row: 63
+      column: 45
+  parent: ~
+- kind:
+    RewriteMockImport: Import
+  location:
+    row: 67
+    column: 4
+  end_location:
+    row: 67
+    column: 51
+  fix:
+    content: "from unittest import mock as foo\n    from unittest import mock as bar\n    from unittest import mock"
+    location:
+      row: 67
+      column: 4
+    end_location:
+      row: 67
+      column: 51
+  parent: ~
+- kind:
+    RewriteMockImport: Attribute
+  location:
+    row: 74
+    column: 4
+  end_location:
+    row: 74
+    column: 13
+  fix:
+    content: mock
+    location:
+      row: 74
+      column: 4
+    end_location:
+      row: 74
+      column: 13
+  parent: ~
+

src/ruff/checks.rs

@@ -1614,10 +1614,7 @@ pub fn ambiguous_unicode_character(
 ) -> Vec<Check> {
     let mut checks = vec![];
 
-    let text = locator.slice_source_code_range(&Range {
-        location: start,
-        end_location: end,
-    });
+    let text = locator.slice_source_code_range(&Range::new(start, end));
 
     let mut col_offset = 0;
     let mut row_offset = 0;
@@ -1648,10 +1645,7 @@ pub fn ambiguous_unicode_character(
                                 representant,
                             ),
                         },
-                        Range {
-                            location,
-                            end_location,
-                        },
+                        Range::new(location, end_location),
                     );
                     if settings.enabled.contains(check.kind.code()) {
                         if matches!(autofix, flags::Autofix::Enabled)

src/source_code_style.rs

@@ -125,10 +125,7 @@ fn detect_indentation(contents: &str, locator: &SourceCodeLocator) -> Option<Ind
     for (_start, tok, end) in lexer::make_tokenizer(contents).flatten() {
         if let Tok::Indent { .. } = tok {
             let start = Location::new(end.row(), 0);
-            let whitespace = locator.slice_source_code_range(&Range {
-                location: start,
-                end_location: end,
-            });
+            let whitespace = locator.slice_source_code_range(&Range::new(start, end));
             return Some(Indentation(whitespace.to_string()));
         }
     }
@@ -139,10 +136,7 @@ fn detect_indentation(contents: &str, locator: &SourceCodeLocator) -> Option<Ind
 fn detect_quote(contents: &str, locator: &SourceCodeLocator) -> Option<Quote> {
     for (start, tok, end) in lexer::make_tokenizer(contents).flatten() {
         if let Tok::String { .. } = tok {
-            let content = locator.slice_source_code_range(&Range {
-                location: start,
-                end_location: end,
-            });
+            let content = locator.slice_source_code_range(&Range::new(start, end));
             if let Some(pattern) = leading_quote(&content) {
                 if pattern.contains('\'') {
                     return Some(Quote::Single);