Use a separate repo for pre-commit (#229)

.pre-commit-config.yaml

@@ -1,5 +1,5 @@
 repos:
-  - repo: https://github.com/charliermarsh/ruff
-    rev: v0.0.38
+  - repo: https://github.com/charliermarsh/ruff-pre-commit
+    rev: v0.0.40
     hooks:
       - id: lint

.pre-commit-hooks.yaml

@@ -1,7 +0,0 @@
-- id: lint
-  name: ruff lint
-  description: Run ruff to lint Python files.
-  entry: ruff
-  language: python
-  types_or: [python]
-  pass_filenames: true

Cargo.lock

@@ -1432,6 +1432,24 @@ dependencies = [
  "windows-sys",
 ]
 
+[[package]]
+name = "path-absolutize"
+version = "3.0.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d3de4b40bd9736640f14c438304c09538159802388febb02c8abaae0846c1f13"
+dependencies = [
+ "path-dedot",
+]
+
+[[package]]
+name = "path-dedot"
+version = "3.0.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d611d5291372b3738a34ebf0d1f849e58b1dcc1101032f76a346eaa1f8ddbb5b"
+dependencies = [
+ "once_cell",
+]
+
 [[package]]
 name = "percent-encoding"
 version = "2.1.0"
@@ -1783,7 +1801,7 @@ dependencies = [
 
 [[package]]
 name = "ruff"
-version = "0.0.38"
+version = "0.0.40"
 dependencies = [
  "anyhow",
  "bincode",
@@ -1802,6 +1820,7 @@ dependencies = [
  "log",
  "notify",
  "once_cell",
+ "path-absolutize",
  "rayon",
  "regex",
  "rustpython-parser",

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "ruff"
-version = "0.0.38"
+version = "0.0.40"
 edition = "2021"
 
 [lib]
@@ -23,6 +23,7 @@ itertools = "0.10.3"
 log = { version = "0.4.17" }
 notify = { version = "4.0.17" }
 once_cell = { version = "1.13.1" }
+path-absolutize = { version = "3.0.13", features = ["once_cell_cache"] }
 rayon = { version = "1.5.3" }
 regex = { version = "1.6.0" }
 rustpython-parser = { features = ["lalrpop"], git = "https://github.com/charliermarsh/RustPython.git", rev = "7d21c6923a506e79cc041708d83cef925efd33f4" }

README.md

@@ -1,7 +1,9 @@
 # ruff
 
+[![image](https://img.shields.io/pypi/v/ruff.svg)](https://pypi.python.org/pypi/ruff)
+[![image](https://img.shields.io/pypi/l/ruff.svg)](https://pypi.python.org/pypi/ruff)
+[![image](https://img.shields.io/pypi/pyversions/ruff.svg)](https://pypi.python.org/pypi/ruff)
 [![Actions status](https://github.com/charliermarsh/ruff/workflows/CI/badge.svg)](https://github.com/charliermarsh/ruff/actions)
-[![PyPI version](https://badge.fury.io/py/ruff.svg)](https://badge.fury.io/py/ruff)
 
 An extremely fast Python linter, written in Rust.
 
@@ -52,14 +54,14 @@ You can run ruff in `--watch` mode to automatically re-run on-change:
 ruff path/to/code/ --watch
 ```
 
-ruff also works with [Pre-Commit](https://pre-commit.com) (requires Cargo on system):
+ruff also works with [pre-commit](https://pre-commit.com):
 
 ```yaml
 repos:
-- repo: https://github.com/charliermarsh/ruff
-  rev: v0.0.38
-  hooks:
-    - id: lint
+  - repo: https://github.com/charliermarsh/ruff-pre-commit
+    rev: v0.0.40
+    hooks:
+      - id: lint
 ```
 
 ## Configuration
@@ -86,7 +88,7 @@ ruff path/to/code/ --select F401 F403
 See `ruff --help` for more:
 
 ```shell
-ruff (v0.0.38)
+ruff (v0.0.40)
 An extremely fast Python linter.
 
 USAGE:
@@ -96,19 +98,44 @@ ARGS:
     <FILES>...
 
 OPTIONS:
-    -e, --exit-zero               Exit with status code "0", even upon detecting errors
-        --exclude <EXCLUDE>...    List of file and/or directory patterns to exclude from checks
-    -f, --fix                     Attempt to automatically fix lint errors
-    -h, --help                    Print help information
-        --ignore <IGNORE>...      List of error codes to ignore
-    -n, --no-cache                Disable cache reads
-    -q, --quiet                   Disable all logging (but still exit with status code "1" upon
-                                  detecting errors)
-        --select <SELECT>...      List of error codes to enable
-    -v, --verbose                 Enable verbose logging
-    -w, --watch                   Run in watch mode by re-running whenever files change
+    -e, --exit-zero
+            Exit with status code "0", even upon detecting errors
+        --exclude <EXCLUDE>...
+            List of paths, used to exclude files and/or directories from checks
+        --extend-exclude <EXTEND_EXCLUDE>...
+            Like --exclude, but adds additional files and directories on top of the excluded ones
+    -f, --fix
+            Attempt to automatically fix lint errors
+        --format <FORMAT>
+            Output serialization format for error messages [default: text] [possible values: text,
+            json]
+    -h, --help
+            Print help information
+        --ignore <IGNORE>...
+            List of error codes to ignore
+    -n, --no-cache
+            Disable cache reads
+    -q, --quiet
+            Disable all logging (but still exit with status code "1" upon detecting errors)
+        --select <SELECT>...
+            List of error codes to enable
+    -v, --verbose
+            Enable verbose logging
+    -V, --version
+            Print version information
+    -w, --watch
+            Run in watch mode by re-running whenever files change
 ```
 
+Exclusions are based on globs, and can be either:
+
+- Single-path patterns, like `.mypy_cache` (to exclude any directory named `.mypy_cache` in the
+  tree), `foo.py` (to exclude any file named `foo.py`), or `foo_*.py` (to exclude any file matching
+  `foo_*.py` ).
+- Relative patterns, like `directory/foo.py` (to exclude that specific file) or `directory/*.py`
+  (to exclude any Python files in `directory`). Note that these paths are relative to the
+  project root (e.g., the directory containing your `pyproject.toml`).
+
 ### Compatibility with Black
 
 ruff is intended to be compatible with [Black](https://github.com/psf/black), and should be
@@ -221,28 +248,28 @@ Add this `pyproject.toml` to the CPython directory:
 [tool.ruff]
 line-length = 88
 exclude = [
-    "Lib/lib2to3/tests/data/bom.py",
-    "Lib/lib2to3/tests/data/crlf.py",
-    "Lib/lib2to3/tests/data/different_encoding.py",
-    "Lib/lib2to3/tests/data/false_encoding.py",
-    "Lib/lib2to3/tests/data/py2_test_grammar.py",
-    "Lib/test/bad_coding2.py",
-    "Lib/test/badsyntax_3131.py",
-    "Lib/test/badsyntax_pep3120.py",
-    "Lib/test/encoded_modules/module_iso_8859_1.py",
-    "Lib/test/encoded_modules/module_koi8_r.py",
-    "Lib/test/test_fstring.py",
-    "Lib/test/test_grammar.py",
-    "Lib/test/test_importlib/test_util.py",
-    "Lib/test/test_named_expressions.py",
-    "Lib/test/test_patma.py",
-    "Lib/test/test_source_encoding.py",
-    "Tools/c-analyzer/c_parser/parser/_delim.py",
-    "Tools/i18n/pygettext.py",
-    "Tools/test2to3/maintest.py",
-    "Tools/test2to3/setup.py",
-    "Tools/test2to3/test/test_foo.py",
-    "Tools/test2to3/test2to3/hello.py",
+    "./resources/test/cpython/Lib/lib2to3/tests/data/bom.py",
+    "./resources/test/cpython/Lib/lib2to3/tests/data/crlf.py",
+    "./resources/test/cpython/Lib/lib2to3/tests/data/different_encoding.py",
+    "./resources/test/cpython/Lib/lib2to3/tests/data/false_encoding.py",
+    "./resources/test/cpython/Lib/lib2to3/tests/data/py2_test_grammar.py",
+    "./resources/test/cpython/Lib/test/bad_coding2.py",
+    "./resources/test/cpython/Lib/test/badsyntax_3131.py",
+    "./resources/test/cpython/Lib/test/badsyntax_pep3120.py",
+    "./resources/test/cpython/Lib/test/encoded_modules/module_iso_8859_1.py",
+    "./resources/test/cpython/Lib/test/encoded_modules/module_koi8_r.py",
+    "./resources/test/cpython/Lib/test/test_fstring.py",
+    "./resources/test/cpython/Lib/test/test_grammar.py",
+    "./resources/test/cpython/Lib/test/test_importlib/test_util.py",
+    "./resources/test/cpython/Lib/test/test_named_expressions.py",
+    "./resources/test/cpython/Lib/test/test_patma.py",
+    "./resources/test/cpython/Lib/test/test_source_encoding.py",
+    "./resources/test/cpython/Tools/c-analyzer/c_parser/parser/_delim.py",
+    "./resources/test/cpython/Tools/i18n/pygettext.py",
+    "./resources/test/cpython/Tools/test2to3/maintest.py",
+    "./resources/test/cpython/Tools/test2to3/setup.py",
+    "./resources/test/cpython/Tools/test2to3/test/test_foo.py",
+    "./resources/test/cpython/Tools/test2to3/test2to3/hello.py",
 ]
 ```
 

examples/generate_rules_table.rs

@@ -1,56 +1,14 @@
 /// Generate a Markdown-compatible table of supported lint rules.
-use ruff::checks::{CheckKind, RejectedCmpop};
+use ruff::checks::{CheckCode, ALL_CHECK_CODES};
 
 fn main() {
-    let mut check_kinds: Vec<CheckKind> = vec![
-        CheckKind::AmbiguousClassName("...".to_string()),
-        CheckKind::AmbiguousFunctionName("...".to_string()),
-        CheckKind::AmbiguousVariableName("...".to_string()),
-        CheckKind::AssertTuple,
-        CheckKind::BreakOutsideLoop,
-        CheckKind::ContinueOutsideLoop,
-        CheckKind::DefaultExceptNotLast,
-        CheckKind::DoNotAssignLambda,
-        CheckKind::DoNotUseBareExcept,
-        CheckKind::DuplicateArgumentName,
-        CheckKind::FStringMissingPlaceholders,
-        CheckKind::ForwardAnnotationSyntaxError("...".to_string()),
-        CheckKind::FutureFeatureNotDefined("...".to_string()),
-        CheckKind::IOError("...".to_string()),
-        CheckKind::IfTuple,
-        CheckKind::ImportStarNotPermitted("...".to_string()),
-        CheckKind::ImportStarUsage("...".to_string()),
-        CheckKind::InvalidPrintSyntax,
-        CheckKind::IsLiteral,
-        CheckKind::LateFutureImport,
-        CheckKind::LineTooLong(89, 88),
-        CheckKind::ModuleImportNotAtTopOfFile,
-        CheckKind::MultiValueRepeatedKeyLiteral,
-        CheckKind::MultiValueRepeatedKeyVariable("...".to_string()),
-        CheckKind::NoAssertEquals,
-        CheckKind::NoneComparison(RejectedCmpop::Eq),
-        CheckKind::NotInTest,
-        CheckKind::NotIsTest,
-        CheckKind::RaiseNotImplemented,
-        CheckKind::ReturnOutsideFunction,
-        CheckKind::SyntaxError("...".to_string()),
-        CheckKind::TooManyExpressionsInStarredAssignment,
-        CheckKind::TrueFalseComparison(true, RejectedCmpop::Eq),
-        CheckKind::TwoStarredExpressions,
-        CheckKind::TypeComparison,
-        CheckKind::UndefinedExport("...".to_string()),
-        CheckKind::UndefinedLocal("...".to_string()),
-        CheckKind::UndefinedName("...".to_string()),
-        CheckKind::UnusedImport("...".to_string()),
-        CheckKind::UnusedVariable("...".to_string()),
-        CheckKind::UselessObjectInheritance("...".to_string()),
-        CheckKind::YieldOutsideFunction,
-    ];
-    check_kinds.sort_by_key(|check_kind| check_kind.code());
+    let mut check_codes: Vec<CheckCode> = ALL_CHECK_CODES.to_vec();
+    check_codes.sort();
 
     println!("| Code | Name | Message |");
     println!("| ---- | ----- | ------- |");
-    for check_kind in check_kinds {
+    for check_code in check_codes {
+        let check_kind = check_code.kind();
         println!(
             "| {} | {} | {} |",
             check_kind.code().as_str(),

resources/test/fixtures/E501.py

@@ -4,3 +4,6 @@
 
 Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
 """
+
+_ = "---------------------------------------------------------------------------AAAAAAA"
+_ = "---------------------------------------------------------------------------亜亜亜亜亜亜亜"

resources/test/fixtures/F821.py

@@ -77,3 +77,8 @@ class Ticket:
 
     def set_status(self, status: Status):
         self.status = status
+
+
+def update_tomato():
+    print(TOMATO)
+    TOMATO = "cherry tomato"

resources/test/fixtures/F841.py

@@ -22,3 +22,10 @@ def g():
 
     bar = (1, 2)
     (c, d) = bar
+
+    (x, y) = baz = bar
+
+
+def h():
+    locals()
+    x = 1

resources/test/fixtures/__init__.py

@@ -0,0 +1,3 @@
+print(__path__)
+
+__all__ = ["a", "b", "c"]

resources/test/fixtures/directory/also_excluded.py

@@ -0,0 +1,9 @@
+a = "abc"
+b = f"ghi{'jkl'}"
+
+c = f"def"
+d = f"def" + "ghi"
+e = (
+    f"def" +
+    "ghi"
+)

resources/test/fixtures/pyproject.toml

@@ -1,47 +1,7 @@
 [tool.ruff]
 line-length = 88
-extend-exclude = ["excluded.py", "migrations"]
-select = [
-    "E402",
-    "E501",
-    "E711",
-    "E712",
-    "E713",
-    "E714",
-    "E721",
-    "E722",
-    "E731",
-    "E741",
-    "E742",
-    "E743",
-    "E902",
-    "E999",
-    "F401",
-    "F403",
-    "F404",
-    "F406",
-    "F407",
-    "F541",
-    "F601",
-    "F602",
-    "F621",
-    "F622",
-    "F631",
-    "F632",
-    "F633",
-    "F634",
-    "F701",
-    "F702",
-    "F704",
-    "F706",
-    "F707",
-    "F722",
-    "F821",
-    "F822",
-    "F823",
-    "F831",
-    "F841",
-    "F901",
-    "R001",
-    "R002",
+extend-exclude = [
+    "excluded.py",
+    "migrations",
+    "directory/also_excluded.py",
 ]

src/ast/checks.rs

@@ -7,7 +7,7 @@ use rustpython_parser::ast::{
 };
 
 use crate::ast::operations::SourceCodeLocator;
-use crate::ast::types::{Binding, BindingKind, Scope};
+use crate::ast::types::{Binding, BindingKind, FunctionScope, Scope, ScopeKind};
 use crate::autofix::{fixer, fixes};
 use crate::checks::{Check, CheckKind, Fix, RejectedCmpop};
 
@@ -67,6 +67,13 @@ pub fn check_not_tests(
 pub fn check_unused_variables(scope: &Scope) -> Vec<Check> {
     let mut checks: Vec<Check> = vec![];
 
+    if matches!(
+        scope.kind,
+        ScopeKind::Function(FunctionScope { uses_locals: true })
+    ) {
+        return checks;
+    }
+
     for (name, binding) in scope.values.iter() {
         // TODO(charlie): Ignore if using `locals`.
         if binding.used.is_none()

src/ast/operations.rs

@@ -101,11 +101,13 @@ pub fn in_nested_block(parent_stack: &[usize], parents: &[&Stmt]) -> bool {
 /// Check if a node represents an unpacking assignment.
 pub fn is_unpacking_assignment(stmt: &Stmt) -> bool {
     if let StmtKind::Assign { targets, value, .. } = &stmt.node {
-        for child in targets {
-            match &child.node {
-                ExprKind::Set { .. } | ExprKind::List { .. } | ExprKind::Tuple { .. } => {}
-                _ => return false,
-            }
+        if !targets.iter().any(|child| {
+            matches!(
+                child.node,
+                ExprKind::Set { .. } | ExprKind::List { .. } | ExprKind::Tuple { .. }
+            )
+        }) {
+            return false;
         }
         match &value.node {
             ExprKind::Set { .. } | ExprKind::List { .. } | ExprKind::Tuple { .. } => return false,

src/ast/types.rs

@@ -8,10 +8,15 @@ fn id() -> usize {
     COUNTER.fetch_add(1, Ordering::Relaxed)
 }
 
+#[derive(Clone, Debug, Default)]
+pub struct FunctionScope {
+    pub uses_locals: bool,
+}
+
 #[derive(Clone, Debug)]
 pub enum ScopeKind {
     Class,
-    Function,
+    Function(FunctionScope),
     Generator,
     Module,
 }
@@ -53,5 +58,7 @@ pub enum BindingKind {
 pub struct Binding {
     pub kind: BindingKind,
     pub location: Location,
-    pub used: Option<usize>,
+    /// Tuple of (scope index, location) indicating the scope and location at which the binding was
+    /// last used.
+    pub used: Option<(usize, Location)>,
 }

src/cache.rs

@@ -1,11 +1,14 @@
 use std::collections::hash_map::DefaultHasher;
-use std::fs::Metadata;
+use std::fs::{create_dir_all, File, Metadata};
 use std::hash::{Hash, Hasher};
+use std::io::Write;
 use std::path::Path;
 
+use anyhow::Result;
 use cacache::Error::EntryNotFound;
 use filetime::FileTime;
 use log::error;
+use path_absolutize::Absolutize;
 use serde::{Deserialize, Serialize};
 
 use crate::autofix::fixer;
@@ -77,12 +80,22 @@ fn cache_key(path: &Path, settings: &Settings, autofix: &fixer::Mode) -> String
     autofix.hash(&mut hasher);
     format!(
         "{}@{}@{}",
-        path.canonicalize().unwrap().to_string_lossy(),
+        path.absolutize().unwrap().to_string_lossy(),
         VERSION,
         hasher.finish()
     )
 }
 
+pub fn init() -> Result<()> {
+    let gitignore_path = Path::new(cache_dir()).join(".gitignore");
+    if gitignore_path.exists() {
+        return Ok(());
+    }
+    create_dir_all(cache_dir())?;
+    let mut file = File::create(gitignore_path)?;
+    file.write_all(b"*").map_err(|e| e.into())
+}
+
 pub fn get(
     path: &Path,
     metadata: &Metadata,

src/check_ast.rs

@@ -9,7 +9,7 @@ use rustpython_parser::parser;
 
 use crate::ast::operations::{extract_all_names, SourceCodeLocator};
 use crate::ast::relocate::relocate_expr;
-use crate::ast::types::{Binding, BindingKind, Scope, ScopeKind};
+use crate::ast::types::{Binding, BindingKind, FunctionScope, Scope, ScopeKind};
 use crate::ast::visitor::{walk_excepthandler, Visitor};
 use crate::ast::{checks, operations, visitor};
 use crate::autofix::fixer;
@@ -26,7 +26,7 @@ struct Checker<'a> {
     locator: SourceCodeLocator<'a>,
     settings: &'a Settings,
     autofix: &'a fixer::Mode,
-    path: &'a str,
+    path: &'a Path,
     // Computed checks.
     checks: Vec<Check>,
     // Retain all scopes and parent nodes, along with a stack of indexes to track which are active
@@ -55,7 +55,7 @@ impl<'a> Checker<'a> {
     pub fn new(
         settings: &'a Settings,
         autofix: &'a fixer::Mode,
-        path: &'a str,
+        path: &'a Path,
         content: &'a str,
     ) -> Checker<'a> {
         Checker {
@@ -184,7 +184,7 @@ where
                                 name.to_string(),
                                 Binding {
                                     kind: BindingKind::Assignment,
-                                    used: Some(global_scope_id),
+                                    used: Some((global_scope_id, stmt.location)),
                                     location: stmt.location,
                                 },
                             );
@@ -416,13 +416,14 @@ where
                             name,
                             Binding {
                                 kind: BindingKind::FutureImportation,
-                                used: Some(
+                                used: Some((
                                     self.scopes[*(self
                                         .scope_stack
                                         .last()
                                         .expect("No current scope found."))]
                                     .id,
-                                ),
+                                    stmt.location,
+                                )),
                                 location: stmt.location,
                             },
                         );
@@ -645,6 +646,33 @@ where
                         self.checks.push(check)
                     }
                 }
+
+                if let ExprKind::Name { id, ctx } = &func.node {
+                    if id == "locals" && matches!(ctx, ExprContext::Load) {
+                        let scope = &mut self.scopes[*(self
+                            .scope_stack
+                            .last_mut()
+                            .expect("No current scope found."))];
+                        if matches!(
+                            scope.kind,
+                            ScopeKind::Function(FunctionScope { uses_locals: false })
+                        ) {
+                            scope.kind = ScopeKind::Function(FunctionScope { uses_locals: true });
+                        }
+                    }
+                }
+
+                //
+                // if id == "locals" {
+                //     let scope = &self.scopes
+                //         [*(self.scope_stack.last().expect("No current scope found."))];
+                //     if matches!(scope.kind, ScopeKind::Function(_)) {
+                //     let parent =
+                //         self.parents[*(self.parent_stack.last().expect("No parent found."))];
+                //         if matches!(parent.node, StmtKind::Call)
+                //     }
+                //
+                // }
             }
             ExprKind::Dict { keys, .. } => {
                 let check_repeated_literals = self.settings.select.contains(&CheckCode::F601);
@@ -1108,7 +1136,7 @@ impl<'a> Checker<'a> {
                     }
                 }
                 if let Some(binding) = scope.values.get_mut(id) {
-                    binding.used = Some(scope_id);
+                    binding.used = Some((scope_id, expr.location));
                     return;
                 }
 
@@ -1117,6 +1145,10 @@ impl<'a> Checker<'a> {
             }
 
             if self.settings.select.contains(&CheckCode::F821) {
+                // Allow __path__.
+                if self.path.ends_with("__init__.py") && id == "__path__" {
+                    return;
+                }
                 self.checks.push(Check::new(
                     CheckKind::UndefinedName(id.clone()),
                     expr.location,
@@ -1131,22 +1163,19 @@ impl<'a> Checker<'a> {
                 &self.scopes[*(self.scope_stack.last().expect("No current scope found."))];
 
             if self.settings.select.contains(&CheckCode::F823)
-                && matches!(current.kind, ScopeKind::Function)
+                && matches!(current.kind, ScopeKind::Function(_))
                 && !current.values.contains_key(id)
             {
                 for scope in self.scopes.iter().rev().skip(1) {
-                    if matches!(scope.kind, ScopeKind::Function | ScopeKind::Module) {
-                        let used = scope
-                            .values
-                            .get(id)
-                            .map(|binding| binding.used)
-                            .unwrap_or_default();
-                        if let Some(scope_id) = used {
-                            if scope_id == current.id {
-                                self.checks.push(Check::new(
-                                    CheckKind::UndefinedLocal(id.clone()),
-                                    expr.location,
-                                ));
+                    if matches!(scope.kind, ScopeKind::Function(_) | ScopeKind::Module) {
+                        if let Some(binding) = scope.values.get(id) {
+                            if let Some((scope_id, location)) = binding.used {
+                                if scope_id == current.id {
+                                    self.checks.push(Check::new(
+                                        CheckKind::UndefinedLocal(id.clone()),
+                                        location,
+                                    ));
+                                }
                             }
                         }
                     }
@@ -1240,12 +1269,12 @@ impl<'a> Checker<'a> {
         }
     }
 
-    fn check_deferred_string_annotations<'b>(&mut self, path: &str, allocator: &'b mut Vec<Expr>)
+    fn check_deferred_string_annotations<'b>(&mut self, allocator: &'b mut Vec<Expr>)
     where
         'b: 'a,
     {
         while let Some((location, expression)) = self.deferred_string_annotations.pop() {
-            if let Ok(mut expr) = parser::parse_expression(expression, path) {
+            if let Ok(mut expr) = parser::parse_expression(expression, "<filename>") {
                 relocate_expr(&mut expr, location);
                 allocator.push(expr);
             } else if self.settings.select.contains(&CheckCode::F722) {
@@ -1264,7 +1293,7 @@ impl<'a> Checker<'a> {
         while let Some((stmt, scopes, parents)) = self.deferred_functions.pop() {
             self.parent_stack = parents;
             self.scope_stack = scopes;
-            self.push_scope(Scope::new(ScopeKind::Function));
+            self.push_scope(Scope::new(ScopeKind::Function(Default::default())));
 
             match &stmt.node {
                 StmtKind::FunctionDef { body, args, .. }
@@ -1288,7 +1317,7 @@ impl<'a> Checker<'a> {
         while let Some((expr, scopes, parents)) = self.deferred_lambdas.pop() {
             self.parent_stack = parents;
             self.scope_stack = scopes;
-            self.push_scope(Scope::new(ScopeKind::Function));
+            self.push_scope(Scope::new(ScopeKind::Function(Default::default())));
 
             if let ExprKind::Lambda { args, body } = &expr.node {
                 self.visit_arguments(args);
@@ -1328,7 +1357,7 @@ impl<'a> Checker<'a> {
             });
 
             if self.settings.select.contains(&CheckCode::F822)
-                && !Path::new(self.path).ends_with("__init__.py")
+                && !self.path.ends_with("__init__.py")
             {
                 if let Some(binding) = all_binding {
                     if let Some(names) = all_names {
@@ -1374,7 +1403,7 @@ pub fn check_ast(
     content: &str,
     settings: &Settings,
     autofix: &fixer::Mode,
-    path: &str,
+    path: &Path,
 ) -> Vec<Check> {
     let mut checker = Checker::new(settings, autofix, path, content);
     checker.push_scope(Scope::new(ScopeKind::Module));
@@ -1391,7 +1420,7 @@ pub fn check_ast(
     checker.check_deferred_assignments();
     checker.check_deferred_annotations();
     let mut allocator = vec![];
-    checker.check_deferred_string_annotations(path, &mut allocator);
+    checker.check_deferred_string_annotations(&mut allocator);
 
     // Reset the scope to module-level, and check all consumed scopes.
     checker.scope_stack = vec![GLOBAL_SCOPE_INDEX];

src/check_lines.rs

@@ -35,7 +35,7 @@ pub fn check_lines(checks: &mut Vec<Check>, contents: &str, settings: &Settings)
 
         // Enforce line length.
         if enforce_line_too_long {
-            let line_length = line.len();
+            let line_length = line.chars().count();
             if should_enforce_line_length(line, line_length, settings.line_length) {
                 let check = Check::new(
                     CheckKind::LineTooLong(line_length, settings.line_length),
@@ -53,3 +53,28 @@ pub fn check_lines(checks: &mut Vec<Check>, contents: &str, settings: &Settings)
     }
     checks.extend(line_checks);
 }
+
+#[cfg(test)]
+mod tests {
+    use super::check_lines;
+    use super::*;
+    use std::collections::BTreeSet;
+
+    #[test]
+    fn e501_non_ascii_char() {
+        let line = "'\u{4e9c}' * 2"; // 7 in UTF-32, 9 in UTF-8.
+        let check_with_max_line_length = |line_length: usize| {
+            let mut checks: Vec<Check> = vec![];
+            let settings = Settings {
+                line_length,
+                exclude: vec![],
+                extend_exclude: vec![],
+                select: BTreeSet::from_iter(vec![CheckCode::E501]),
+            };
+            check_lines(&mut checks, line, &settings);
+            return checks;
+        };
+        assert!(!check_with_max_line_length(6).is_empty());
+        assert!(check_with_max_line_length(7).is_empty());
+    }
+}

src/checks.rs

@@ -6,7 +6,52 @@ use regex::Regex;
 use rustpython_parser::ast::Location;
 use serde::{Deserialize, Serialize};
 
-#[derive(Debug, PartialEq, Eq, Serialize, Deserialize, Hash, PartialOrd, Ord)]
+pub const ALL_CHECK_CODES: [CheckCode; 42] = [
+    CheckCode::E402,
+    CheckCode::E501,
+    CheckCode::E711,
+    CheckCode::E712,
+    CheckCode::E713,
+    CheckCode::E714,
+    CheckCode::E721,
+    CheckCode::E722,
+    CheckCode::E731,
+    CheckCode::E741,
+    CheckCode::E742,
+    CheckCode::E743,
+    CheckCode::E902,
+    CheckCode::E999,
+    CheckCode::F401,
+    CheckCode::F403,
+    CheckCode::F404,
+    CheckCode::F406,
+    CheckCode::F407,
+    CheckCode::F541,
+    CheckCode::F601,
+    CheckCode::F602,
+    CheckCode::F621,
+    CheckCode::F622,
+    CheckCode::F631,
+    CheckCode::F632,
+    CheckCode::F633,
+    CheckCode::F634,
+    CheckCode::F701,
+    CheckCode::F702,
+    CheckCode::F704,
+    CheckCode::F706,
+    CheckCode::F707,
+    CheckCode::F722,
+    CheckCode::F821,
+    CheckCode::F822,
+    CheckCode::F823,
+    CheckCode::F831,
+    CheckCode::F841,
+    CheckCode::F901,
+    CheckCode::R001,
+    CheckCode::R002,
+];
+
+#[derive(Debug, PartialEq, Eq, Clone, Serialize, Deserialize, Hash, PartialOrd, Ord)]
 pub enum CheckCode {
     E402,
     E501,
@@ -160,6 +205,54 @@ impl CheckCode {
             _ => &LintSource::AST,
         }
     }
+
+    /// A placeholder representation of the CheckKind for the check.
+    pub fn kind(&self) -> CheckKind {
+        match self {
+            CheckCode::E742 => CheckKind::AmbiguousClassName("...".to_string()),
+            CheckCode::E743 => CheckKind::AmbiguousFunctionName("...".to_string()),
+            CheckCode::E741 => CheckKind::AmbiguousVariableName("...".to_string()),
+            CheckCode::F631 => CheckKind::AssertTuple,
+            CheckCode::F701 => CheckKind::BreakOutsideLoop,
+            CheckCode::F702 => CheckKind::ContinueOutsideLoop,
+            CheckCode::F707 => CheckKind::DefaultExceptNotLast,
+            CheckCode::E731 => CheckKind::DoNotAssignLambda,
+            CheckCode::E722 => CheckKind::DoNotUseBareExcept,
+            CheckCode::F831 => CheckKind::DuplicateArgumentName,
+            CheckCode::F541 => CheckKind::FStringMissingPlaceholders,
+            CheckCode::F722 => CheckKind::ForwardAnnotationSyntaxError("...".to_string()),
+            CheckCode::F407 => CheckKind::FutureFeatureNotDefined("...".to_string()),
+            CheckCode::E902 => CheckKind::IOError("...".to_string()),
+            CheckCode::F634 => CheckKind::IfTuple,
+            CheckCode::F406 => CheckKind::ImportStarNotPermitted("...".to_string()),
+            CheckCode::F403 => CheckKind::ImportStarUsage("...".to_string()),
+            CheckCode::F633 => CheckKind::InvalidPrintSyntax,
+            CheckCode::F632 => CheckKind::IsLiteral,
+            CheckCode::F404 => CheckKind::LateFutureImport,
+            CheckCode::E501 => CheckKind::LineTooLong(89, 88),
+            CheckCode::E402 => CheckKind::ModuleImportNotAtTopOfFile,
+            CheckCode::F601 => CheckKind::MultiValueRepeatedKeyLiteral,
+            CheckCode::F602 => CheckKind::MultiValueRepeatedKeyVariable("...".to_string()),
+            CheckCode::R002 => CheckKind::NoAssertEquals,
+            CheckCode::E711 => CheckKind::NoneComparison(RejectedCmpop::Eq),
+            CheckCode::E713 => CheckKind::NotInTest,
+            CheckCode::E714 => CheckKind::NotIsTest,
+            CheckCode::F901 => CheckKind::RaiseNotImplemented,
+            CheckCode::F706 => CheckKind::ReturnOutsideFunction,
+            CheckCode::E999 => CheckKind::SyntaxError("...".to_string()),
+            CheckCode::F621 => CheckKind::TooManyExpressionsInStarredAssignment,
+            CheckCode::E712 => CheckKind::TrueFalseComparison(true, RejectedCmpop::Eq),
+            CheckCode::F622 => CheckKind::TwoStarredExpressions,
+            CheckCode::E721 => CheckKind::TypeComparison,
+            CheckCode::F822 => CheckKind::UndefinedExport("...".to_string()),
+            CheckCode::F823 => CheckKind::UndefinedLocal("...".to_string()),
+            CheckCode::F821 => CheckKind::UndefinedName("...".to_string()),
+            CheckCode::F401 => CheckKind::UnusedImport("...".to_string()),
+            CheckCode::F841 => CheckKind::UnusedVariable("...".to_string()),
+            CheckCode::R001 => CheckKind::UselessObjectInheritance("...".to_string()),
+            CheckCode::F704 => CheckKind::YieldOutsideFunction,
+        }
+    }
 }
 
 #[allow(clippy::upper_case_acronyms)]

src/fs.rs

@@ -1,27 +1,53 @@
+use std::borrow::Cow;
 use std::fs::File;
 use std::io::{BufReader, Read};
+use std::ops::Deref;
 use std::path::{Path, PathBuf};
 
-use anyhow::Result;
-use glob::Pattern;
+use anyhow::{anyhow, Result};
 use log::debug;
+use path_absolutize::path_dedot;
+use path_absolutize::Absolutize;
 use walkdir::{DirEntry, WalkDir};
 
-fn is_excluded(path: &Path, exclude: &[Pattern]) -> bool {
-    if let Some(file_name) = path.file_name() {
-        if let Some(file_name) = file_name.to_str() {
-            for pattern in exclude {
-                if pattern.matches(file_name) {
+use crate::settings::FilePattern;
+
+/// Extract the absolute path and basename (as strings) from a Path.
+fn extract_path_names(path: &Path) -> Result<(&str, &str)> {
+    let file_path = path
+        .to_str()
+        .ok_or_else(|| anyhow!("Unable to parse filename: {:?}", path))?;
+    let file_basename = path
+        .file_name()
+        .ok_or_else(|| anyhow!("Unable to parse filename: {:?}", path))?
+        .to_str()
+        .ok_or_else(|| anyhow!("Unable to parse filename: {:?}", path))?;
+    Ok((file_path, file_basename))
+}
+
+fn is_excluded(file_path: &str, file_basename: &str, exclude: &[FilePattern]) -> bool {
+    for pattern in exclude {
+        match &pattern {
+            FilePattern::Simple(basename) => {
+                if *basename == file_basename {
+                    return true;
+                }
+            }
+            FilePattern::Complex(absolute, basename) => {
+                if absolute.matches(file_path) {
+                    return true;
+                }
+                if basename
+                    .as_ref()
+                    .map(|pattern| pattern.matches(file_basename))
+                    .unwrap_or_default()
+                {
                     return true;
                 }
             }
-            false
-        } else {
-            false
         }
-    } else {
-        false
     }
+    false
 }
 
 fn is_included(path: &Path) -> bool {
@@ -30,27 +56,53 @@ fn is_included(path: &Path) -> bool {
 }
 
 pub fn iter_python_files<'a>(
-    path: &'a PathBuf,
-    exclude: &'a [Pattern],
-    extend_exclude: &'a [Pattern],
+    path: &'a Path,
+    exclude: &'a [FilePattern],
+    extend_exclude: &'a [FilePattern],
 ) -> impl Iterator<Item = DirEntry> + 'a {
-    WalkDir::new(path)
+    // Run some checks over the provided patterns, to enable optimizations below.
+    let has_exclude = !exclude.is_empty();
+    let has_extend_exclude = !extend_exclude.is_empty();
+    let exclude_simple = exclude
+        .iter()
+        .all(|pattern| matches!(pattern, FilePattern::Simple(_)));
+    let extend_exclude_simple = exclude
+        .iter()
+        .all(|pattern| matches!(pattern, FilePattern::Simple(_)));
+
+    WalkDir::new(normalize_path(path))
         .follow_links(true)
         .into_iter()
-        .filter_entry(|entry| {
-            if exclude.is_empty() && extend_exclude.is_empty() {
+        .filter_entry(move |entry| {
+            if !has_exclude && !has_extend_exclude {
                 return true;
             }
 
             let path = entry.path();
-            if is_excluded(path, exclude) {
-                debug!("Ignored path via `exclude`: {:?}", path);
-                false
-            } else if is_excluded(path, extend_exclude) {
-                debug!("Ignored path via `extend-exclude`: {:?}", path);
-                false
-            } else {
-                true
+            match extract_path_names(path) {
+                Ok((file_path, file_basename)) => {
+                    let file_type = entry.file_type();
+
+                    if has_exclude
+                        && (!exclude_simple || file_type.is_dir())
+                        && is_excluded(file_path, file_basename, exclude)
+                    {
+                        debug!("Ignored path via `exclude`: {:?}", path);
+                        false
+                    } else if has_extend_exclude
+                        && (!extend_exclude_simple || file_type.is_dir())
+                        && is_excluded(file_path, file_basename, extend_exclude)
+                    {
+                        debug!("Ignored path via `extend-exclude`: {:?}", path);
+                        false
+                    } else {
+                        true
+                    }
+                }
+                Err(_) => {
+                    debug!("Ignored path due to error in parsing: {:?}", path);
+                    true
+                }
             }
         })
         .filter_map(|entry| entry.ok())
@@ -60,6 +112,37 @@ pub fn iter_python_files<'a>(
         })
 }
 
+/// Convert any path to an absolute path (based on the current working directory).
+pub fn normalize_path(path: &Path) -> PathBuf {
+    if path == Path::new(".") || path == Path::new("..") {
+        return path.to_path_buf();
+    }
+    if let Ok(path) = path.absolutize() {
+        return path.to_path_buf();
+    }
+    path.to_path_buf()
+}
+
+/// Convert any path to an absolute path (based on the specified project root).
+pub fn normalize_path_to(path: &Path, project_root: &Path) -> PathBuf {
+    if path == Path::new(".") || path == Path::new("..") {
+        return path.to_path_buf();
+    }
+    if let Ok(path) = path.absolutize_from(project_root) {
+        return path.to_path_buf();
+    }
+    path.to_path_buf()
+}
+
+/// Convert an absolute path to be relative to the current working directory.
+pub fn relativize_path(path: &Path) -> Cow<str> {
+    if let Ok(path) = path.strip_prefix(path_dedot::CWD.deref()) {
+        return path.to_string_lossy();
+    }
+    path.to_string_lossy()
+}
+
+/// Read a file's contents from disk.
 pub fn read_file(path: &Path) -> Result<String> {
     let file = File::open(path)?;
     let mut buf_reader = BufReader::new(file);
@@ -72,41 +155,95 @@ pub fn read_file(path: &Path) -> Result<String> {
 mod tests {
     use std::path::Path;
 
-    use glob::Pattern;
+    use anyhow::Result;
+    use path_absolutize::Absolutize;
 
-    use crate::fs::{is_excluded, is_included};
+    use crate::fs::{extract_path_names, is_excluded, is_included};
+    use crate::settings::FilePattern;
 
     #[test]
     fn inclusions() {
-        let path = Path::new("foo/bar/baz.py");
-        assert!(is_included(path));
+        let path = Path::new("foo/bar/baz.py").absolutize().unwrap();
+        assert!(is_included(&path));
 
-        let path = Path::new("foo/bar/baz.pyi");
-        assert!(is_included(path));
+        let path = Path::new("foo/bar/baz.pyi").absolutize().unwrap();
+        assert!(is_included(&path));
 
-        let path = Path::new("foo/bar/baz.js");
-        assert!(!is_included(path));
+        let path = Path::new("foo/bar/baz.js").absolutize().unwrap();
+        assert!(!is_included(&path));
 
-        let path = Path::new("foo/bar/baz");
-        assert!(!is_included(path));
+        let path = Path::new("foo/bar/baz").absolutize().unwrap();
+        assert!(!is_included(&path));
     }
 
     #[test]
-    fn exclusions() {
-        let path = Path::new("foo");
-        let exclude = vec![Pattern::new("foo").unwrap()];
-        assert!(is_excluded(path, &exclude));
+    fn exclusions() -> Result<()> {
+        let project_root = Path::new("/tmp/");
 
-        let path = Path::new("foo/bar");
-        let exclude = vec![Pattern::new("bar").unwrap()];
-        assert!(is_excluded(path, &exclude));
+        let path = Path::new("foo").absolutize_from(project_root).unwrap();
+        let exclude = vec![FilePattern::from_user(
+            "foo",
+            &Some(project_root.to_path_buf()),
+        )];
+        let (file_path, file_basename) = extract_path_names(&path)?;
+        assert!(is_excluded(file_path, file_basename, &exclude));
 
-        let path = Path::new("foo/bar/baz.py");
-        let exclude = vec![Pattern::new("baz.py").unwrap()];
-        assert!(is_excluded(path, &exclude));
+        let path = Path::new("foo/bar").absolutize_from(project_root).unwrap();
+        let exclude = vec![FilePattern::from_user(
+            "bar",
+            &Some(project_root.to_path_buf()),
+        )];
+        let (file_path, file_basename) = extract_path_names(&path)?;
+        assert!(is_excluded(file_path, file_basename, &exclude));
 
-        let path = Path::new("foo/bar/baz.py");
-        let exclude = vec![Pattern::new("baz").unwrap()];
-        assert!(!is_excluded(path, &exclude));
+        let path = Path::new("foo/bar/baz.py")
+            .absolutize_from(project_root)
+            .unwrap();
+        let exclude = vec![FilePattern::from_user(
+            "baz.py",
+            &Some(project_root.to_path_buf()),
+        )];
+        let (file_path, file_basename) = extract_path_names(&path)?;
+        assert!(is_excluded(file_path, file_basename, &exclude));
+
+        let path = Path::new("foo/bar").absolutize_from(project_root).unwrap();
+        let exclude = vec![FilePattern::from_user(
+            "foo/bar",
+            &Some(project_root.to_path_buf()),
+        )];
+        let (file_path, file_basename) = extract_path_names(&path)?;
+        assert!(is_excluded(file_path, file_basename, &exclude));
+
+        let path = Path::new("foo/bar/baz.py")
+            .absolutize_from(project_root)
+            .unwrap();
+        let exclude = vec![FilePattern::from_user(
+            "foo/bar/baz.py",
+            &Some(project_root.to_path_buf()),
+        )];
+        let (file_path, file_basename) = extract_path_names(&path)?;
+        assert!(is_excluded(file_path, file_basename, &exclude));
+
+        let path = Path::new("foo/bar/baz.py")
+            .absolutize_from(project_root)
+            .unwrap();
+        let exclude = vec![FilePattern::from_user(
+            "foo/bar/*.py",
+            &Some(project_root.to_path_buf()),
+        )];
+        let (file_path, file_basename) = extract_path_names(&path)?;
+        assert!(is_excluded(file_path, file_basename, &exclude));
+
+        let path = Path::new("foo/bar/baz.py")
+            .absolutize_from(project_root)
+            .unwrap();
+        let exclude = vec![FilePattern::from_user(
+            "baz",
+            &Some(project_root.to_path_buf()),
+        )];
+        let (file_path, file_basename) = extract_path_names(&path)?;
+        assert!(!is_excluded(file_path, file_basename, &exclude));
+
+        Ok(())
     }
 }

src/lib.rs

@@ -2,7 +2,7 @@ extern crate core;
 
 mod ast;
 mod autofix;
-mod cache;
+pub mod cache;
 pub mod check_ast;
 mod check_lines;
 pub mod checks;
@@ -10,6 +10,7 @@ pub mod fs;
 pub mod linter;
 pub mod logging;
 pub mod message;
-mod pyproject;
+pub mod printer;
+pub mod pyproject;
 mod python;
 pub mod settings;

src/linter.rs

@@ -13,10 +13,12 @@ use crate::message::Message;
 use crate::settings::Settings;
 use crate::{cache, fs};
 
-fn check_path(path: &Path, settings: &Settings, autofix: &fixer::Mode) -> Result<Vec<Check>> {
-    // Read the file from disk.
-    let contents = fs::read_file(path)?;
-
+fn check_path(
+    path: &Path,
+    contents: &str,
+    settings: &Settings,
+    autofix: &fixer::Mode,
+) -> Result<Vec<Check>> {
     // Aggregate all checks.
     let mut checks: Vec<Check> = vec![];
 
@@ -26,13 +28,12 @@ fn check_path(path: &Path, settings: &Settings, autofix: &fixer::Mode) -> Result
         .iter()
         .any(|check_code| matches!(check_code.lint_source(), LintSource::AST))
     {
-        let path = path.to_string_lossy();
-        let python_ast = parser::parse_program(&contents, &path)?;
-        checks.extend(check_ast(&python_ast, &contents, settings, autofix, &path));
+        let python_ast = parser::parse_program(contents, "<filename>")?;
+        checks.extend(check_ast(&python_ast, contents, settings, autofix, path));
     }
 
     // Run the lines-based checks.
-    check_lines(&mut checks, &contents, settings);
+    check_lines(&mut checks, contents, settings);
 
     Ok(checks)
 }
@@ -55,7 +56,7 @@ pub fn lint_path(
     let contents = fs::read_file(path)?;
 
     // Generate checks.
-    let mut checks = check_path(path, settings, autofix)?;
+    let mut checks = check_path(path, &contents, settings, autofix)?;
 
     // Apply autofix.
     if matches!(autofix, fixer::Mode::Apply) {
@@ -85,10 +86,20 @@ mod tests {
     use anyhow::Result;
 
     use crate::autofix::fixer;
-    use crate::checks::CheckCode;
-    use crate::linter::check_path;
+    use crate::checks::{Check, CheckCode};
+    use crate::fs;
+    use crate::linter;
     use crate::settings;
 
+    fn check_path(
+        path: &Path,
+        settings: &settings::Settings,
+        autofix: &fixer::Mode,
+    ) -> Result<Vec<Check>> {
+        let contents = fs::read_file(path)?;
+        linter::check_path(path, &contents, settings, autofix)
+    }
+
     #[test]
     fn e402() -> Result<()> {
         let mut checks = check_path(
@@ -752,6 +763,23 @@ mod tests {
         Ok(())
     }
 
+    #[test]
+    fn init() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/__init__.py"),
+            &settings::Settings {
+                line_length: 88,
+                exclude: vec![],
+                extend_exclude: vec![],
+                select: BTreeSet::from([CheckCode::F821, CheckCode::F822]),
+            },
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
+
     #[test]
     fn future_annotations() -> Result<()> {
         let mut checks = check_path(

src/main.rs

@@ -1,3 +1,5 @@
+extern crate core;
+
 use std::path::PathBuf;
 use std::process::ExitCode;
 use std::sync::mpsc::channel;
@@ -6,19 +8,21 @@ use std::time::Instant;
 use anyhow::Result;
 use clap::{Parser, ValueHint};
 use colored::Colorize;
-use glob::Pattern;
 use log::{debug, error};
 use notify::{raw_watcher, RecursiveMode, Watcher};
 use rayon::prelude::*;
 use walkdir::DirEntry;
 
+use ::ruff::cache;
 use ::ruff::checks::CheckCode;
 use ::ruff::checks::CheckKind;
 use ::ruff::fs::iter_python_files;
 use ::ruff::linter::lint_path;
 use ::ruff::logging::set_up_logging;
 use ::ruff::message::Message;
-use ::ruff::settings::Settings;
+use ::ruff::printer::{Printer, SerializationFormat};
+use ::ruff::pyproject;
+use ::ruff::settings::{FilePattern, Settings};
 use ::ruff::tell_user;
 
 const CARGO_PKG_NAME: &str = env!("CARGO_PKG_NAME");
@@ -27,6 +31,7 @@ const CARGO_PKG_VERSION: &str = env!("CARGO_PKG_VERSION");
 #[derive(Debug, Parser)]
 #[clap(name = format!("{CARGO_PKG_NAME} (v{CARGO_PKG_VERSION})"))]
 #[clap(about = "An extremely fast Python linter.", long_about = None)]
+#[clap(version)]
 struct Cli {
     #[clap(parse(from_os_str), value_hint = ValueHint::AnyPath, required = true)]
     files: Vec<PathBuf>,
@@ -56,10 +61,13 @@ struct Cli {
     ignore: Vec<CheckCode>,
     /// List of paths, used to exclude files and/or directories from checks.
     #[clap(long, multiple = true)]
-    exclude: Vec<Pattern>,
+    exclude: Vec<String>,
     /// Like --exclude, but adds additional files and directories on top of the excluded ones.
     #[clap(long, multiple = true)]
-    extend_exclude: Vec<Pattern>,
+    extend_exclude: Vec<String>,
+    /// Output serialization format for error messages.
+    #[clap(long, arg_enum, default_value_t=SerializationFormat::Text)]
+    format: SerializationFormat,
 }
 
 #[cfg(feature = "update-informer")]
@@ -142,60 +150,25 @@ fn run_once(
     Ok(messages)
 }
 
-fn report_once(messages: &[Message]) -> Result<()> {
-    let (fixed, outstanding): (Vec<&Message>, Vec<&Message>) =
-        messages.iter().partition(|message| message.fixed);
-    let num_fixable = outstanding
-        .iter()
-        .filter(|message| message.kind.fixable())
-        .count();
-
-    if !outstanding.is_empty() {
-        for message in &outstanding {
-            println!("{}", message);
-        }
-        println!();
-    }
-
-    if !fixed.is_empty() {
-        println!(
-            "Found {} error(s) ({} fixed).",
-            outstanding.len(),
-            fixed.len()
-        );
-    } else {
-        println!("Found {} error(s).", outstanding.len());
-    }
-
-    if num_fixable > 0 {
-        println!("{num_fixable} potentially fixable with the --fix option.");
-    }
-
-    Ok(())
-}
-
-fn report_continuously(messages: &[Message]) -> Result<()> {
-    tell_user!(
-        "Found {} error(s). Watching for file changes.",
-        messages.len(),
-    );
-
-    if !messages.is_empty() {
-        println!();
-        for message in messages {
-            println!("{}", message);
-        }
-    }
-
-    Ok(())
-}
-
 fn inner_main() -> Result<ExitCode> {
     let cli = Cli::parse();
 
     set_up_logging(cli.verbose)?;
 
-    let mut settings = Settings::from_paths(&cli.files);
+    // Find the project root and pyproject.toml.
+    let project_root = pyproject::find_project_root(&cli.files);
+    match &project_root {
+        Some(path) => debug!("Found project root at: {:?}", path),
+        None => debug!("Unable to identify project root; assuming current directory..."),
+    };
+    let pyproject = pyproject::find_pyproject_toml(&project_root);
+    match &pyproject {
+        Some(path) => debug!("Found pyproject.toml at: {:?}", path),
+        None => debug!("Unable to find pyproject.toml; using default settings..."),
+    };
+
+    // Parse the settings from the pyproject.toml and command-line arguments.
+    let mut settings = Settings::from_pyproject(&pyproject, &project_root);
     if !cli.select.is_empty() {
         settings.select(cli.select);
     }
@@ -203,24 +176,39 @@ fn inner_main() -> Result<ExitCode> {
         settings.ignore(&cli.ignore);
     }
     if !cli.exclude.is_empty() {
-        settings.exclude = cli.exclude;
+        settings.exclude = cli
+            .exclude
+            .iter()
+            .map(|path| FilePattern::from_user(path, &project_root))
+            .collect();
     }
     if !cli.extend_exclude.is_empty() {
-        settings.extend_exclude = cli.extend_exclude;
+        settings.extend_exclude = cli
+            .extend_exclude
+            .iter()
+            .map(|path| FilePattern::from_user(path, &project_root))
+            .collect();
     }
 
+    cache::init()?;
+
+    let mut printer = Printer::new(cli.format);
     if cli.watch {
         if cli.fix {
-            println!("Warning: --fix is not enabled in watch mode.")
+            println!("Warning: --fix is not enabled in watch mode.");
+        }
+
+        if cli.format != SerializationFormat::Text {
+            println!("Warning: --format 'text' is used in watch mode.");
         }
 
         // Perform an initial run instantly.
-        clearscreen::clear()?;
+        printer.clear_screen()?;
         tell_user!("Starting linter in watch mode...\n");
 
         let messages = run_once(&cli.files, &settings, !cli.no_cache, false)?;
         if !cli.quiet {
-            report_continuously(&messages)?;
+            printer.write_continuously(&messages)?;
         }
 
         // Configure the file watcher.
@@ -235,12 +223,12 @@ fn inner_main() -> Result<ExitCode> {
                 Ok(e) => {
                     if let Some(path) = e.path {
                         if path.to_string_lossy().ends_with(".py") {
-                            clearscreen::clear()?;
+                            printer.clear_screen()?;
                             tell_user!("File change detected...\n");
 
                             let messages = run_once(&cli.files, &settings, !cli.no_cache, false)?;
                             if !cli.quiet {
-                                report_continuously(&messages)?;
+                                printer.write_continuously(&messages)?;
                             }
                         }
                     }
@@ -251,7 +239,7 @@ fn inner_main() -> Result<ExitCode> {
     } else {
         let messages = run_once(&cli.files, &settings, !cli.no_cache, cli.fix)?;
         if !cli.quiet {
-            report_once(&messages)?;
+            printer.write_once(&messages)?;
         }
 
         #[cfg(feature = "update-informer")]

src/message.rs

@@ -1,11 +1,13 @@
 use std::cmp::Ordering;
 use std::fmt;
+use std::path::Path;
 
 use colored::Colorize;
 use rustpython_parser::ast::Location;
 use serde::{Deserialize, Serialize};
 
 use crate::checks::CheckKind;
+use crate::fs::relativize_path;
 
 #[derive(Debug, PartialEq, Eq, Serialize, Deserialize)]
 pub struct Message {
@@ -36,7 +38,8 @@ impl fmt::Display for Message {
         write!(
             f,
             "{}{}{}{}{}{} {} {}",
-            self.filename.white().bold(),
+            relativize_path(Path::new(&self.filename)).white().bold(),
+            // self.filename.white(),
             ":".cyan(),
             self.location.row(),
             ":".cyan(),

src/printer.rs

@@ -0,0 +1,80 @@
+use colored::Colorize;
+
+use anyhow::Result;
+use clap::ValueEnum;
+
+use crate::message::Message;
+use crate::tell_user;
+
+#[derive(Clone, Copy, ValueEnum, PartialEq, Eq, Debug)]
+pub enum SerializationFormat {
+    Text,
+    Json,
+}
+
+pub struct Printer {
+    format: SerializationFormat,
+}
+
+impl Printer {
+    pub fn new(format: SerializationFormat) -> Self {
+        Self { format }
+    }
+
+    pub fn write_once(&mut self, messages: &[Message]) -> Result<()> {
+        let (fixed, outstanding): (Vec<&Message>, Vec<&Message>) =
+            messages.iter().partition(|message| message.fixed);
+        let num_fixable = outstanding
+            .iter()
+            .filter(|message| message.kind.fixable())
+            .count();
+
+        match self.format {
+            SerializationFormat::Json => {
+                println!("{}", serde_json::to_string_pretty(&messages)?)
+            }
+            SerializationFormat::Text => {
+                if !fixed.is_empty() {
+                    println!(
+                        "Found {} error(s) ({} fixed).",
+                        outstanding.len(),
+                        fixed.len()
+                    )
+                } else {
+                    println!("Found {} error(s).", outstanding.len())
+                }
+
+                for message in outstanding {
+                    println!("{}", message)
+                }
+
+                if num_fixable > 0 {
+                    println!("{num_fixable} potentially fixable with the --fix option.")
+                }
+            }
+        }
+
+        Ok(())
+    }
+
+    pub fn write_continuously(&mut self, messages: &[Message]) -> Result<()> {
+        tell_user!(
+            "Found {} error(s). Watching for file changes.",
+            messages.len(),
+        );
+
+        if !messages.is_empty() {
+            println!();
+            for message in messages {
+                println!("{}", message)
+            }
+        }
+
+        Ok(())
+    }
+
+    pub fn clear_screen(&mut self) -> Result<()> {
+        clearscreen::clear()?;
+        Ok(())
+    }
+}

src/pyproject.rs

@@ -1,33 +1,32 @@
+use std::ops::Deref;
 use std::path::{Path, PathBuf};
 
 use anyhow::Result;
 use common_path::common_path_all;
-use log::debug;
+use path_absolutize::path_dedot;
 use serde::Deserialize;
 
 use crate::checks::CheckCode;
 use crate::fs;
 
-pub fn load_config(paths: &[PathBuf]) -> Config {
-    match find_project_root(paths) {
-        Some(project_root) => match find_pyproject_toml(&project_root) {
-            Some(path) => {
-                debug!("Found pyproject.toml at: {:?}", path);
-                match parse_pyproject_toml(&path) {
-                    Ok(pyproject) => pyproject
-                        .tool
-                        .and_then(|tool| tool.ruff)
-                        .unwrap_or_default(),
-                    Err(e) => {
-                        println!("Failed to load pyproject.toml: {:?}", e);
-                        println!("Falling back to default configuration...");
-                        Default::default()
-                    }
-                }
+pub fn load_config(pyproject: &Option<PathBuf>) -> Config {
+    match pyproject {
+        Some(pyproject) => match parse_pyproject_toml(pyproject) {
+            Ok(pyproject) => pyproject
+                .tool
+                .and_then(|tool| tool.ruff)
+                .unwrap_or_default(),
+            Err(e) => {
+                println!("Failed to load pyproject.toml: {:?}", e);
+                println!("Falling back to default configuration...");
+                Default::default()
             }
-            None => Default::default(),
         },
-        None => Default::default(),
+        None => {
+            println!("No pyproject.toml found.");
+            println!("Falling back to default configuration...");
+            Default::default()
+        }
     }
 }
 
@@ -35,8 +34,8 @@ pub fn load_config(paths: &[PathBuf]) -> Config {
 #[serde(deny_unknown_fields, rename_all = "kebab-case")]
 pub struct Config {
     pub line_length: Option<usize>,
-    pub exclude: Option<Vec<PathBuf>>,
-    pub extend_exclude: Option<Vec<PathBuf>>,
+    pub exclude: Option<Vec<String>>,
+    pub extend_exclude: Option<Vec<String>>,
     pub select: Option<Vec<CheckCode>>,
     pub ignore: Option<Vec<CheckCode>>,
 }
@@ -56,20 +55,32 @@ fn parse_pyproject_toml(path: &Path) -> Result<PyProject> {
     toml::from_str(&contents).map_err(|e| e.into())
 }
 
-fn find_pyproject_toml(path: &Path) -> Option<PathBuf> {
-    let path_pyproject_toml = path.join("pyproject.toml");
-    if path_pyproject_toml.is_file() {
-        return Some(path_pyproject_toml);
+pub fn find_pyproject_toml(path: &Option<PathBuf>) -> Option<PathBuf> {
+    if let Some(path) = path {
+        let path_pyproject_toml = path.join("pyproject.toml");
+        if path_pyproject_toml.is_file() {
+            return Some(path_pyproject_toml);
+        }
     }
+
     find_user_pyproject_toml()
 }
 
 fn find_user_pyproject_toml() -> Option<PathBuf> {
-    dirs::home_dir().map(|path| path.join(".ruff"))
+    let mut path = dirs::config_dir()?;
+    path.push("ruff");
+    path.push("pyproject.toml");
+    if path.is_file() {
+        Some(path)
+    } else {
+        None
+    }
 }
 
-fn find_project_root(sources: &[PathBuf]) -> Option<PathBuf> {
-    if let Some(prefix) = common_path_all(sources.iter().map(PathBuf::as_path)) {
+pub fn find_project_root(sources: &[PathBuf]) -> Option<PathBuf> {
+    let cwd = path_dedot::CWD.deref();
+    let absolute_sources: Vec<PathBuf> = sources.iter().map(|source| cwd.join(source)).collect();
+    if let Some(prefix) = common_path_all(absolute_sources.iter().map(PathBuf::as_path)) {
         for directory in prefix.ancestors() {
             if directory.join(".git").is_dir() {
                 return Some(directory.to_path_buf());
@@ -88,7 +99,8 @@ fn find_project_root(sources: &[PathBuf]) -> Option<PathBuf> {
 
 #[cfg(test)]
 mod tests {
-    use std::path::{Path, PathBuf};
+    use std::env::current_dir;
+    use std::path::PathBuf;
 
     use anyhow::Result;
 
@@ -160,7 +172,7 @@ exclude = ["foo.py"]
             Some(Tools {
                 ruff: Some(Config {
                     line_length: None,
-                    exclude: Some(vec![Path::new("foo.py").to_path_buf()]),
+                    exclude: Some(vec!["foo.py".to_string()]),
                     extend_exclude: None,
                     select: None,
                     ignore: None,
@@ -241,13 +253,15 @@ other-attribute = 1
 
     #[test]
     fn find_and_parse_pyproject_toml() -> Result<()> {
+        let cwd = current_dir()?;
         let project_root =
             find_project_root(&[PathBuf::from("resources/test/fixtures/__init__.py")])
                 .expect("Unable to find project root.");
-        assert_eq!(project_root, Path::new("resources/test/fixtures"));
+        assert_eq!(project_root, cwd.join("resources/test/fixtures"));
 
-        let path = find_pyproject_toml(&project_root).expect("Unable to find pyproject.toml.");
-        assert_eq!(path, Path::new("resources/test/fixtures/pyproject.toml"));
+        let path =
+            find_pyproject_toml(&Some(project_root)).expect("Unable to find pyproject.toml.");
+        assert_eq!(path, cwd.join("resources/test/fixtures/pyproject.toml"));
 
         let pyproject = parse_pyproject_toml(&path)?;
         let config = pyproject
@@ -260,53 +274,11 @@ other-attribute = 1
                 line_length: Some(88),
                 exclude: None,
                 extend_exclude: Some(vec![
-                    Path::new("excluded.py").to_path_buf(),
-                    Path::new("migrations").to_path_buf()
-                ]),
-                select: Some(vec![
-                    CheckCode::E402,
-                    CheckCode::E501,
-                    CheckCode::E711,
-                    CheckCode::E712,
-                    CheckCode::E713,
-                    CheckCode::E714,
-                    CheckCode::E721,
-                    CheckCode::E722,
-                    CheckCode::E731,
-                    CheckCode::E741,
-                    CheckCode::E742,
-                    CheckCode::E743,
-                    CheckCode::E902,
-                    CheckCode::E999,
-                    CheckCode::F401,
-                    CheckCode::F403,
-                    CheckCode::F404,
-                    CheckCode::F406,
-                    CheckCode::F407,
-                    CheckCode::F541,
-                    CheckCode::F601,
-                    CheckCode::F602,
-                    CheckCode::F621,
-                    CheckCode::F622,
-                    CheckCode::F631,
-                    CheckCode::F632,
-                    CheckCode::F633,
-                    CheckCode::F634,
-                    CheckCode::F701,
-                    CheckCode::F702,
-                    CheckCode::F704,
-                    CheckCode::F706,
-                    CheckCode::F707,
-                    CheckCode::F722,
-                    CheckCode::F821,
-                    CheckCode::F822,
-                    CheckCode::F823,
-                    CheckCode::F831,
-                    CheckCode::F841,
-                    CheckCode::F901,
-                    CheckCode::R001,
-                    CheckCode::R002,
+                    "excluded.py".to_string(),
+                    "migrations".to_string(),
+                    "directory/also_excluded.py".to_string(),
                 ]),
+                select: None,
                 ignore: None,
             }
         );

src/settings.rs

@@ -1,18 +1,44 @@
 use std::collections::BTreeSet;
 use std::hash::{Hash, Hasher};
-use std::path::PathBuf;
+use std::path::{Path, PathBuf};
 
 use glob::Pattern;
 use once_cell::sync::Lazy;
 
-use crate::checks::CheckCode;
+use crate::checks::{CheckCode, ALL_CHECK_CODES};
+use crate::fs;
 use crate::pyproject::load_config;
 
+#[derive(Debug, Clone)]
+pub enum FilePattern {
+    Simple(&'static str),
+    Complex(Pattern, Option<Pattern>),
+}
+
+impl FilePattern {
+    pub fn from_user(pattern: &str, project_root: &Option<PathBuf>) -> Self {
+        let path = Path::new(pattern);
+        let absolute_path = match project_root {
+            Some(project_root) => fs::normalize_path_to(path, project_root),
+            None => fs::normalize_path(path),
+        };
+
+        let absolute = Pattern::new(&absolute_path.to_string_lossy()).expect("Invalid pattern.");
+        let basename = if !pattern.contains(std::path::MAIN_SEPARATOR) {
+            Some(Pattern::new(pattern).expect("Invalid pattern."))
+        } else {
+            None
+        };
+
+        FilePattern::Complex(absolute, basename)
+    }
+}
+
 #[derive(Debug)]
 pub struct Settings {
     pub line_length: usize,
-    pub exclude: Vec<Pattern>,
-    pub extend_exclude: Vec<Pattern>,
+    pub exclude: Vec<FilePattern>,
+    pub extend_exclude: Vec<FilePattern>,
     pub select: BTreeSet<CheckCode>,
 }
 
@@ -24,42 +50,42 @@ impl Hash for Settings {
         }
     }
 }
-static DEFAULT_EXCLUDE: Lazy<Vec<Pattern>> = Lazy::new(|| {
+
+static DEFAULT_EXCLUDE: Lazy<Vec<FilePattern>> = Lazy::new(|| {
     vec![
-        Pattern::new(".bzr").unwrap(),
-        Pattern::new(".direnv").unwrap(),
-        Pattern::new(".eggs").unwrap(),
-        Pattern::new(".git").unwrap(),
-        Pattern::new(".hg").unwrap(),
-        Pattern::new(".mypy_cache").unwrap(),
-        Pattern::new(".nox").unwrap(),
-        Pattern::new(".pants.d").unwrap(),
-        Pattern::new(".svn").unwrap(),
-        Pattern::new(".tox").unwrap(),
-        Pattern::new(".venv").unwrap(),
-        Pattern::new("__pypackages__").unwrap(),
-        Pattern::new("_build").unwrap(),
-        Pattern::new("buck-out").unwrap(),
-        Pattern::new("build").unwrap(),
-        Pattern::new("dist").unwrap(),
-        Pattern::new("node_modules").unwrap(),
-        Pattern::new("venv").unwrap(),
+        FilePattern::Simple(".bzr"),
+        FilePattern::Simple(".direnv"),
+        FilePattern::Simple(".eggs"),
+        FilePattern::Simple(".git"),
+        FilePattern::Simple(".hg"),
+        FilePattern::Simple(".mypy_cache"),
+        FilePattern::Simple(".nox"),
+        FilePattern::Simple(".pants.d"),
+        FilePattern::Simple(".ruff_cache"),
+        FilePattern::Simple(".svn"),
+        FilePattern::Simple(".tox"),
+        FilePattern::Simple(".venv"),
+        FilePattern::Simple("__pypackages__"),
+        FilePattern::Simple("_build"),
+        FilePattern::Simple("buck-out"),
+        FilePattern::Simple("build"),
+        FilePattern::Simple("dist"),
+        FilePattern::Simple("node_modules"),
+        FilePattern::Simple("venv"),
     ]
 });
 
 impl Settings {
-    pub fn from_paths(paths: &[PathBuf]) -> Self {
-        let config = load_config(paths);
+    pub fn from_pyproject(path: &Option<PathBuf>, project_root: &Option<PathBuf>) -> Self {
+        let config = load_config(path);
         let mut settings = Settings {
             line_length: config.line_length.unwrap_or(88),
             exclude: config
                 .exclude
                 .map(|paths| {
                     paths
-                        .into_iter()
-                        .map(|path| {
-                            Pattern::new(&path.to_string_lossy()).expect("Invalid pattern.")
-                        })
+                        .iter()
+                        .map(|path| FilePattern::from_user(path, project_root))
                         .collect()
                 })
                 .unwrap_or_else(|| DEFAULT_EXCLUDE.clone()),
@@ -67,59 +93,16 @@ impl Settings {
                 .extend_exclude
                 .map(|paths| {
                     paths
-                        .into_iter()
-                        .map(|path| {
-                            Pattern::new(&path.to_string_lossy()).expect("Invalid pattern.")
-                        })
+                        .iter()
+                        .map(|path| FilePattern::from_user(path, project_root))
                         .collect()
                 })
                 .unwrap_or_default(),
-            select: BTreeSet::from_iter(config.select.unwrap_or_else(|| {
-                vec![
-                    CheckCode::E402,
-                    CheckCode::E501,
-                    CheckCode::E711,
-                    CheckCode::E712,
-                    CheckCode::E713,
-                    CheckCode::E714,
-                    CheckCode::E721,
-                    CheckCode::E722,
-                    CheckCode::E731,
-                    CheckCode::E741,
-                    CheckCode::E742,
-                    CheckCode::E743,
-                    CheckCode::E902,
-                    CheckCode::E999,
-                    CheckCode::F401,
-                    CheckCode::F403,
-                    CheckCode::F406,
-                    CheckCode::F407,
-                    CheckCode::F541,
-                    CheckCode::F601,
-                    CheckCode::F602,
-                    CheckCode::F621,
-                    CheckCode::F622,
-                    CheckCode::F631,
-                    CheckCode::F632,
-                    CheckCode::F633,
-                    CheckCode::F634,
-                    CheckCode::F701,
-                    CheckCode::F702,
-                    CheckCode::F704,
-                    CheckCode::F706,
-                    CheckCode::F707,
-                    CheckCode::F722,
-                    CheckCode::F821,
-                    CheckCode::F822,
-                    CheckCode::F823,
-                    CheckCode::F831,
-                    CheckCode::F841,
-                    CheckCode::F901,
-                    // Disable refactoring codes by default.
-                    // CheckCode::R001,
-                    // CheckCode::R002,
-                ]
-            })),
+            select: if let Some(select) = config.select {
+                BTreeSet::from_iter(select)
+            } else {
+                BTreeSet::from_iter(ALL_CHECK_CODES)
+            },
         };
         if let Some(ignore) = &config.ignore {
             settings.ignore(ignore);

src/snapshots/ruff__linter__tests__f821.snap

@@ -32,4 +32,10 @@ expression: checks
     row: 58
     column: 5
   fix: ~
+- kind:
+    UndefinedName: TOMATO
+  location:
+    row: 83
+    column: 11
+  fix: ~
 

src/snapshots/ruff__linter__tests__init.snap

@@ -0,0 +1,6 @@
+---
+source: src/linter.rs
+expression: checks
+---
+[]
+