Support hierarchical settings for nested directories (#1190)

src/commands.rs

@@ -1,19 +1,21 @@
-use std::path::PathBuf;
+use std::path::{Path, PathBuf};
 
 use anyhow::{bail, Result};
 use serde::Serialize;
 use walkdir::DirEntry;
 
 use crate::checks::CheckCode;
+use crate::cli::Overrides;
 use crate::fs::iter_python_files;
+use crate::resolver::{discover_settings, Resolver};
 use crate::settings::types::SerializationFormat;
 use crate::{Configuration, Settings};
 
 /// Print the user-facing configuration settings.
 pub fn show_settings(
     configuration: &Configuration,
-    project_root: Option<&PathBuf>,
-    pyproject: Option<&PathBuf>,
+    project_root: Option<&Path>,
+    pyproject: Option<&Path>,
 ) {
     println!("Resolved configuration: {configuration:#?}");
     println!("Found project root at: {project_root:?}");
@@ -21,13 +23,23 @@ pub fn show_settings(
 }
 
 /// Show the list of files to be checked based on current settings.
-pub fn show_files(files: &[PathBuf], settings: &Settings) {
+pub fn show_files(files: &[PathBuf], default: &Settings, overrides: &Overrides) {
+    // Discover the settings for the filesystem hierarchy.
+    let settings = discover_settings(files, overrides);
+    let resolver = Resolver {
+        default,
+        settings: &settings,
+    };
+
+    // Collect all files in the hierarchy.
     let mut entries: Vec<DirEntry> = files
         .iter()
-        .flat_map(|path| iter_python_files(path, &settings.exclude, &settings.extend_exclude))
+        .flat_map(|path| iter_python_files(path, &resolver))
         .flatten()
         .collect();
     entries.sort_by(|a, b| a.path().cmp(b.path()));
+
+    // Print the list of files.
     for entry in entries {
         println!("{}", entry.path().to_string_lossy());
     }

src/fs.rs

@@ -11,6 +11,7 @@ use rustc_hash::FxHashSet;
 use walkdir::{DirEntry, WalkDir};
 
 use crate::checks::CheckCode;
+use crate::resolver::Resolver;
 
 /// Extract the absolute path and basename (as strings) from a Path.
 fn extract_path_names(path: &Path) -> Result<(&str, &str)> {
@@ -30,33 +31,62 @@ fn is_excluded(file_path: &str, file_basename: &str, exclude: &globset::GlobSet)
 }
 
 fn is_included(path: &Path) -> bool {
-    let file_name = path.to_string_lossy();
-    file_name.ends_with(".py") || file_name.ends_with(".pyi")
+    path.extension()
+        .map_or(false, |ext| ext == "py" || ext == "pyi")
 }
 
+/// Find all `pyproject.toml` files for a given `Path`. Both parents and
+/// children will be included in the resulting `Vec`.
+pub fn iter_pyproject_files(path: &Path) -> Vec<PathBuf> {
+    let mut paths = Vec::new();
+
+    // Search for `pyproject.toml` files in all parent directories.
+    let path = normalize_path(path);
+    for path in path.ancestors() {
+        if path.is_dir() {
+            let toml_path = path.join("pyproject.toml");
+            if toml_path.exists() {
+                paths.push(toml_path);
+            }
+        }
+    }
+
+    // Search for `pyproject.toml` files in all child directories.
+    for path in WalkDir::new(path)
+        .into_iter()
+        .filter_entry(|entry| {
+            entry.file_name().to_str().map_or(false, |file_name| {
+                entry.depth() == 0 || !file_name.starts_with('.')
+            })
+        })
+        .filter_map(std::result::Result::ok)
+        .filter(|entry| entry.path().ends_with("pyproject.toml"))
+    {
+        paths.push(path.into_path());
+    }
+
+    paths
+}
+
+/// Find all Python (`.py` and `.pyi` files) in a given `Path`.
 pub fn iter_python_files<'a>(
     path: &'a Path,
-    exclude: &'a globset::GlobSet,
-    extend_exclude: &'a globset::GlobSet,
+    resolver: &'a Resolver<'a>,
 ) -> impl Iterator<Item = Result<DirEntry, walkdir::Error>> + 'a {
-    // 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();
-
     WalkDir::new(normalize_path(path))
         .into_iter()
         .filter_entry(move |entry| {
-            if !has_exclude && !has_extend_exclude {
-                return true;
-            }
-
             let path = entry.path();
+            let settings = resolver.resolve(path);
+            let exclude = &settings.exclude;
+            let extend_exclude = &settings.extend_exclude;
+
             match extract_path_names(path) {
                 Ok((file_path, file_basename)) => {
-                    if has_exclude && is_excluded(file_path, file_basename, exclude) {
+                    if !exclude.is_empty() && is_excluded(file_path, file_basename, exclude) {
                         debug!("Ignored path via `exclude`: {:?}", path);
                         false
-                    } else if has_extend_exclude
+                    } else if !extend_exclude.is_empty()
                         && is_excluded(file_path, file_basename, extend_exclude)
                     {
                         debug!("Ignored path via `extend-exclude`: {:?}", path);
@@ -131,7 +161,7 @@ pub(crate) fn read_file(path: &Path) -> Result<String> {
 
 #[cfg(test)]
 mod tests {
-    use std::path::{Path, PathBuf};
+    use std::path::Path;
 
     use anyhow::Result;
     use globset::GlobSet;
@@ -155,7 +185,7 @@ mod tests {
         assert!(!is_included(&path));
     }
 
-    fn make_exclusion(file_pattern: FilePattern, project_root: Option<&PathBuf>) -> GlobSet {
+    fn make_exclusion(file_pattern: FilePattern, project_root: Option<&Path>) -> GlobSet {
         let mut builder = globset::GlobSetBuilder::new();
         file_pattern.add_to(&mut builder, project_root).unwrap();
         builder.build().unwrap()
@@ -171,7 +201,7 @@ mod tests {
         assert!(is_excluded(
             file_path,
             file_basename,
-            &make_exclusion(exclude, Some(&project_root.to_path_buf()))
+            &make_exclusion(exclude, Some(project_root))
         ));
 
         let path = Path::new("foo/bar").absolutize_from(project_root).unwrap();
@@ -180,7 +210,7 @@ mod tests {
         assert!(is_excluded(
             file_path,
             file_basename,
-            &make_exclusion(exclude, Some(&project_root.to_path_buf()))
+            &make_exclusion(exclude, Some(project_root))
         ));
 
         let path = Path::new("foo/bar/baz.py")
@@ -191,7 +221,7 @@ mod tests {
         assert!(is_excluded(
             file_path,
             file_basename,
-            &make_exclusion(exclude, Some(&project_root.to_path_buf()))
+            &make_exclusion(exclude, Some(project_root))
         ));
 
         let path = Path::new("foo/bar").absolutize_from(project_root).unwrap();
@@ -200,7 +230,7 @@ mod tests {
         assert!(is_excluded(
             file_path,
             file_basename,
-            &make_exclusion(exclude, Some(&project_root.to_path_buf()))
+            &make_exclusion(exclude, Some(project_root))
         ));
 
         let path = Path::new("foo/bar/baz.py")
@@ -211,7 +241,7 @@ mod tests {
         assert!(is_excluded(
             file_path,
             file_basename,
-            &make_exclusion(exclude, Some(&project_root.to_path_buf()))
+            &make_exclusion(exclude, Some(project_root))
         ));
 
         let path = Path::new("foo/bar/baz.py")
@@ -222,7 +252,7 @@ mod tests {
         assert!(is_excluded(
             file_path,
             file_basename,
-            &make_exclusion(exclude, Some(&project_root.to_path_buf()))
+            &make_exclusion(exclude, Some(project_root))
         ));
 
         let path = Path::new("foo/bar/baz.py")
@@ -233,7 +263,7 @@ mod tests {
         assert!(!is_excluded(
             file_path,
             file_basename,
-            &make_exclusion(exclude, Some(&project_root.to_path_buf()))
+            &make_exclusion(exclude, Some(project_root))
         ));
 
         Ok(())

src/iterators.rs

@@ -0,0 +1,16 @@
+#[cfg(not(target_family = "wasm"))]
+use rayon::prelude::*;
+
+/// Shim that calls `par_iter` except for wasm because there's no wasm support
+/// in rayon yet (there is a shim to be used for the web, but it requires js
+/// cooperation) Unfortunately, `ParallelIterator` does not implement `Iterator`
+/// so the signatures diverge
+#[cfg(not(target_family = "wasm"))]
+pub fn par_iter<T: Sync>(iterable: &[T]) -> impl ParallelIterator<Item = &T> {
+    iterable.par_iter()
+}
+
+#[cfg(target_family = "wasm")]
+pub fn par_iter<T: Sync>(iterable: &[T]) -> impl Iterator<Item = &T> {
+    iterable.iter()
+}

src/lib.rs

@@ -58,6 +58,7 @@ pub mod flake8_tidy_imports;
 mod flake8_unused_arguments;
 pub mod fs;
 mod isort;
+pub mod iterators;
 mod lex;
 pub mod linter;
 pub mod logging;
@@ -73,6 +74,7 @@ mod pygrep_hooks;
 mod pylint;
 mod python;
 mod pyupgrade;
+pub mod resolver;
 mod ruff;
 mod rustpython_helpers;
 pub mod settings;
@@ -97,8 +99,8 @@ pub fn check(path: &Path, contents: &str, autofix: bool) -> Result<Vec<Check>> {
     };
 
     let settings = Settings::from_configuration(
-        Configuration::from_pyproject(pyproject.as_ref(), project_root.as_ref())?,
-        project_root.as_ref(),
+        Configuration::from_pyproject(pyproject.as_ref())?,
+        project_root.as_deref(),
     )?;
 
     // Tokenize once.

src/main.rs

@@ -19,12 +19,14 @@ use std::time::Instant;
 
 use ::ruff::autofix::fixer;
 use ::ruff::checks::{CheckCode, CheckKind};
-use ::ruff::cli::{extract_log_level, Cli};
+use ::ruff::cli::{extract_log_level, Cli, Overrides};
 use ::ruff::fs::iter_python_files;
+use ::ruff::iterators::par_iter;
 use ::ruff::linter::{add_noqa_to_path, autoformat_path, lint_path, lint_stdin, Diagnostics};
 use ::ruff::logging::{set_up_logging, LogLevel};
 use ::ruff::message::Message;
 use ::ruff::printer::Printer;
+use ::ruff::resolver::Resolver;
 use ::ruff::settings::configuration::Configuration;
 use ::ruff::settings::types::SerializationFormat;
 use ::ruff::settings::{pyproject, Settings};
@@ -38,23 +40,10 @@ use log::{debug, error};
 use notify::{recommended_watcher, RecursiveMode, Watcher};
 #[cfg(not(target_family = "wasm"))]
 use rayon::prelude::*;
+use ruff::resolver::discover_settings;
 use rustpython_ast::Location;
 use walkdir::DirEntry;
 
-/// Shim that calls `par_iter` except for wasm because there's no wasm support
-/// in rayon yet (there is a shim to be used for the web, but it requires js
-/// cooperation) Unfortunately, `ParallelIterator` does not implement `Iterator`
-/// so the signatures diverge
-#[cfg(not(target_family = "wasm"))]
-fn par_iter<T: Sync>(iterable: &Vec<T>) -> impl ParallelIterator<Item = &T> {
-    iterable.par_iter()
-}
-
-#[cfg(target_family = "wasm")]
-fn par_iter<T: Sync>(iterable: &Vec<T>) -> impl Iterator<Item = &T> {
-    iterable.iter()
-}
-
 fn read_from_stdin() -> Result<String> {
     let mut buffer = String::new();
     io::stdin().lock().read_to_string(&mut buffer)?;
@@ -74,15 +63,23 @@ fn run_once_stdin(
 
 fn run_once(
     files: &[PathBuf],
-    settings: &Settings,
+    default: &Settings,
+    overrides: &Overrides,
     cache: bool,
     autofix: &fixer::Mode,
 ) -> Diagnostics {
+    // Discover the settings for the filesystem hierarchy.
+    let settings = discover_settings(files, overrides);
+    let resolver = Resolver {
+        default,
+        settings: &settings,
+    };
+
     // Collect all the files to check.
     let start = Instant::now();
     let paths: Vec<Result<DirEntry, walkdir::Error>> = files
         .iter()
-        .flat_map(|path| iter_python_files(path, &settings.exclude, &settings.extend_exclude))
+        .flat_map(|path| iter_python_files(path, &resolver))
         .collect();
     let duration = start.elapsed();
     debug!("Identified files to lint in: {:?}", duration);
@@ -93,6 +90,7 @@ fn run_once(
             match entry {
                 Ok(entry) => {
                     let path = entry.path();
+                    let settings = resolver.resolve(path);
                     lint_path(path, settings, &cache.into(), autofix)
                         .map_err(|e| (Some(path.to_owned()), e.to_string()))
                 }
@@ -104,6 +102,7 @@ fn run_once(
             }
             .unwrap_or_else(|(path, message)| {
                 if let Some(path) = path {
+                    let settings = resolver.resolve(&path);
                     if settings.enabled.contains(&CheckCode::E902) {
                         Diagnostics::new(vec![Message {
                             kind: CheckKind::IOError(message),
@@ -135,12 +134,19 @@ fn run_once(
     diagnostics
 }
 
-fn add_noqa(files: &[PathBuf], settings: &Settings) -> usize {
+fn add_noqa(files: &[PathBuf], default: &Settings, overrides: &Overrides) -> usize {
+    // Discover the settings for the filesystem hierarchy.
+    let settings = discover_settings(files, overrides);
+    let resolver = Resolver {
+        default,
+        settings: &settings,
+    };
+
     // Collect all the files to check.
     let start = Instant::now();
     let paths: Vec<DirEntry> = files
         .iter()
-        .flat_map(|path| iter_python_files(path, &settings.exclude, &settings.extend_exclude))
+        .flat_map(|path| iter_python_files(path, &resolver))
         .flatten()
         .collect();
     let duration = start.elapsed();
@@ -150,6 +156,7 @@ fn add_noqa(files: &[PathBuf], settings: &Settings) -> usize {
     let modifications: usize = par_iter(&paths)
         .filter_map(|entry| {
             let path = entry.path();
+            let settings = resolver.resolve(path);
             match add_noqa_to_path(path, settings) {
                 Ok(count) => Some(count),
                 Err(e) => {
@@ -166,12 +173,19 @@ fn add_noqa(files: &[PathBuf], settings: &Settings) -> usize {
     modifications
 }
 
-fn autoformat(files: &[PathBuf], settings: &Settings) -> usize {
+fn autoformat(files: &[PathBuf], default: &Settings, overrides: &Overrides) -> usize {
+    // Discover the settings for the filesystem hierarchy.
+    let settings = discover_settings(files, overrides);
+    let resolver = Resolver {
+        default,
+        settings: &settings,
+    };
+
     // Collect all the files to format.
     let start = Instant::now();
     let paths: Vec<DirEntry> = files
         .iter()
-        .flat_map(|path| iter_python_files(path, &settings.exclude, &settings.extend_exclude))
+        .flat_map(|path| iter_python_files(path, &resolver))
         .flatten()
         .collect();
     let duration = start.elapsed();
@@ -204,29 +218,45 @@ fn inner_main() -> Result<ExitCode> {
     set_up_logging(&log_level)?;
 
     if let Some(shell) = cli.generate_shell_completion {
-        shell.generate(&mut Cli::command(), &mut std::io::stdout());
+        shell.generate(&mut Cli::command(), &mut io::stdout());
         return Ok(ExitCode::SUCCESS);
     }
 
     // Find the project root and pyproject.toml.
-    let config: Option<PathBuf> = cli.config;
-    let project_root = config.as_ref().map_or_else(
+    // TODO(charlie): look in the current directory, but respect `--config`.
+    let project_root = cli.config.as_ref().map_or_else(
         || pyproject::find_project_root(&cli.files),
         |config| config.parent().map(fs::normalize_path),
     );
-    let pyproject = config.or_else(|| pyproject::find_pyproject_toml(project_root.as_ref()));
+    let pyproject = cli
+        .config
+        .or_else(|| pyproject::find_pyproject_toml(project_root.as_ref()));
+    match &project_root {
+        Some(path) => debug!("Found project root at: {:?}", path),
+        None => debug!("Unable to identify project root; assuming current directory..."),
+    };
+    match &pyproject {
+        Some(path) => debug!("Found pyproject.toml at: {:?}", path),
+        None => debug!("Unable to find pyproject.toml; using default settings..."),
+    };
 
     // Reconcile configuration from pyproject.toml and command-line arguments.
-    let mut configuration =
-        Configuration::from_pyproject(pyproject.as_ref(), project_root.as_ref())?;
-    configuration.merge(overrides);
+    let mut configuration = Configuration::from_pyproject(pyproject.as_ref())?;
+    configuration.merge(&overrides);
 
     if cli.show_settings && cli.show_files {
         eprintln!("Error: specify --show-settings or show-files (not both).");
         return Ok(ExitCode::FAILURE);
     }
+
     if cli.show_settings {
-        commands::show_settings(&configuration, project_root.as_ref(), pyproject.as_ref());
+        // TODO(charlie): This would be more useful if required a single file, and told
+        // you the settings used to lint that file.
+        commands::show_settings(
+            &configuration,
+            project_root.as_deref(),
+            pyproject.as_deref(),
+        );
         return Ok(ExitCode::SUCCESS);
     }
 
@@ -240,18 +270,7 @@ fn inner_main() -> Result<ExitCode> {
     };
     let format = configuration.format;
 
-    let settings = Settings::from_configuration(configuration, project_root.as_ref())?;
-
-    // Now that we've inferred the appropriate log level, add some debug
-    // information.
-    match &project_root {
-        Some(path) => debug!("Found project root at: {:?}", path),
-        None => debug!("Unable to identify project root; assuming current directory..."),
-    };
-    match &pyproject {
-        Some(path) => debug!("Found pyproject.toml at: {:?}", path),
-        None => debug!("Unable to find pyproject.toml; using default settings..."),
-    };
+    let settings = Settings::from_configuration(configuration, project_root.as_deref())?;
 
     if let Some(code) = cli.explain {
         commands::explain(&code, format)?;
@@ -259,7 +278,7 @@ fn inner_main() -> Result<ExitCode> {
     }
 
     if cli.show_files {
-        commands::show_files(&cli.files, &settings);
+        commands::show_files(&cli.files, &settings, &overrides);
         return Ok(ExitCode::SUCCESS);
     }
 
@@ -289,7 +308,13 @@ fn inner_main() -> Result<ExitCode> {
         printer.clear_screen()?;
         printer.write_to_user("Starting linter in watch mode...\n");
 
-        let messages = run_once(&cli.files, &settings, cache_enabled, &fixer::Mode::None);
+        let messages = run_once(
+            &cli.files,
+            &settings,
+            &overrides,
+            cache_enabled,
+            &fixer::Mode::None,
+        );
         printer.write_continuously(&messages)?;
 
         // Configure the file watcher.
@@ -305,15 +330,20 @@ fn inner_main() -> Result<ExitCode> {
                     let paths = e?.paths;
                     let py_changed = paths.iter().any(|p| {
                         p.extension()
-                            .map(|ext| ext.eq_ignore_ascii_case("py"))
+                            .map(|ext| ext == "py" || ext == "pyi")
                             .unwrap_or_default()
                     });
                     if py_changed {
                         printer.clear_screen()?;
                         printer.write_to_user("File change detected...\n");
 
-                        let messages =
-                            run_once(&cli.files, &settings, cache_enabled, &fixer::Mode::None);
+                        let messages = run_once(
+                            &cli.files,
+                            &settings,
+                            &overrides,
+                            cache_enabled,
+                            &fixer::Mode::None,
+                        );
                         printer.write_continuously(&messages)?;
                     }
                 }
@@ -321,12 +351,12 @@ fn inner_main() -> Result<ExitCode> {
             }
         }
     } else if cli.add_noqa {
-        let modifications = add_noqa(&cli.files, &settings);
+        let modifications = add_noqa(&cli.files, &settings, &overrides);
         if modifications > 0 && log_level >= LogLevel::Default {
             println!("Added {modifications} noqa directives.");
         }
     } else if cli.autoformat {
-        let modifications = autoformat(&cli.files, &settings);
+        let modifications = autoformat(&cli.files, &settings, &overrides);
         if modifications > 0 && log_level >= LogLevel::Default {
             println!("Formatted {modifications} files.");
         }
@@ -339,7 +369,7 @@ fn inner_main() -> Result<ExitCode> {
             let path = Path::new(&filename);
             run_once_stdin(&settings, path, &fix)?
         } else {
-            run_once(&cli.files, &settings, cache_enabled, &fix)
+            run_once(&cli.files, &settings, &overrides, cache_enabled, &fix)
         };
 
         // Always try to print violations (the printer itself may suppress output),

src/resolver.rs

@@ -0,0 +1,62 @@
+//! Discover and resolve `Settings` from the filesystem hierarchy.
+
+use std::cmp::Reverse;
+use std::path::{Path, PathBuf};
+
+use anyhow::{anyhow, Result};
+use log::error;
+
+use crate::cli::Overrides;
+use crate::fs::iter_pyproject_files;
+use crate::settings::configuration::Configuration;
+use crate::settings::{pyproject, Settings};
+
+pub struct Resolver<'a> {
+    pub settings: &'a [(PathBuf, Settings)],
+    pub default: &'a Settings,
+}
+
+impl<'a> Resolver<'a> {
+    pub fn resolve(&'a self, path: &Path) -> &'a Settings {
+        self.settings
+            .iter()
+            .find(|(root, _)| path.starts_with(root))
+            .map_or(self.default, |(_, settings)| settings)
+    }
+}
+
+/// Extract the `Settings` from a given `pyproject.toml`.
+pub fn settings_for_path(pyproject: &Path, overrides: &Overrides) -> Result<(PathBuf, Settings)> {
+    let project_root = pyproject
+        .parent()
+        .ok_or_else(|| anyhow!("Expected pyproject.toml to be in a directory"))?
+        .to_path_buf();
+    let options = pyproject::load_options(pyproject)?;
+    let mut configuration = Configuration::from_options(options)?;
+    configuration.merge(overrides);
+    let settings = Settings::from_configuration(configuration, Some(&project_root))?;
+    Ok((project_root, settings))
+}
+
+/// Discover all `Settings` objects within the relevant filesystem hierarchy.
+pub fn discover_settings(files: &[PathBuf], overrides: &Overrides) -> Vec<(PathBuf, Settings)> {
+    // Collect all `pyproject.toml` files.
+    let mut pyprojects: Vec<PathBuf> = files
+        .iter()
+        .flat_map(|path| iter_pyproject_files(path))
+        .collect();
+    pyprojects.sort_unstable_by_key(|path| Reverse(path.to_string_lossy().len()));
+    pyprojects.dedup();
+
+    // Read every `pyproject.toml`.
+    pyprojects
+        .into_iter()
+        .filter_map(|pyproject| match settings_for_path(&pyproject, overrides) {
+            Ok((project_root, settings)) => Some((project_root, settings)),
+            Err(error) => {
+                error!("Failed to read settings: {error}");
+                None
+            }
+        })
+        .collect::<Vec<_>>()
+}

src/settings/configuration.rs

@@ -5,18 +5,19 @@
 use std::path::{Path, PathBuf};
 
 use anyhow::{anyhow, Result};
+use log::debug;
 use once_cell::sync::Lazy;
-use path_absolutize::path_dedot;
 use regex::Regex;
 use rustc_hash::FxHashSet;
 
 use crate::checks_gen::{CheckCodePrefix, CATEGORIES};
 use crate::cli::{collect_per_file_ignores, Overrides};
+use crate::settings::options::Options;
 use crate::settings::pyproject::load_options;
 use crate::settings::types::{FilePattern, PerFileIgnore, PythonVersion, SerializationFormat};
 use crate::{
     flake8_annotations, flake8_bugbear, flake8_import_conventions, flake8_quotes,
-    flake8_tidy_imports, fs, isort, mccabe, pep8_naming, pyupgrade,
+    flake8_tidy_imports, isort, mccabe, pep8_naming, pyupgrade,
 };
 
 #[derive(Debug)]
@@ -80,11 +81,18 @@ static DEFAULT_DUMMY_VARIABLE_RGX: Lazy<Regex> =
     Lazy::new(|| Regex::new("^(_+|(_+[a-zA-Z0-9_]*[a-zA-Z0-9]+?))$").unwrap());
 
 impl Configuration {
-    pub fn from_pyproject(
-        pyproject: Option<&PathBuf>,
-        project_root: Option<&PathBuf>,
-    ) -> Result<Self> {
-        let options = load_options(pyproject)?;
+    pub fn from_pyproject(pyproject: Option<&PathBuf>) -> Result<Self> {
+        Self::from_options(pyproject.map_or_else(
+            || {
+                debug!("No pyproject.toml found.");
+                debug!("Falling back to default configuration...");
+                Ok(Options::default())
+            },
+            |path| load_options(path),
+        )?)
+    }
+
+    pub fn from_options(options: Options) -> Result<Self> {
         Ok(Configuration {
             allowed_confusables: FxHashSet::from_iter(
                 options.allowed_confusables.unwrap_or_default(),
@@ -95,21 +103,10 @@ impl Configuration {
                 None => DEFAULT_DUMMY_VARIABLE_RGX.clone(),
             },
             src: options.src.map_or_else(
-                || {
-                    vec![match project_root {
-                        Some(project_root) => project_root.clone(),
-                        None => path_dedot::CWD.clone(),
-                    }]
-                },
+                || vec![Path::new(".").to_path_buf()],
                 |src| {
                     src.iter()
-                        .map(|path| {
-                            let path = Path::new(path);
-                            match project_root {
-                                Some(project_root) => fs::normalize_path_to(path, project_root),
-                                None => fs::normalize_path(path),
-                            }
-                        })
+                        .map(|path| Path::new(path).to_path_buf())
                         .collect()
                 },
             ),
@@ -187,54 +184,54 @@ impl Configuration {
         })
     }
 
-    pub fn merge(&mut self, overrides: Overrides) {
-        if let Some(dummy_variable_rgx) = overrides.dummy_variable_rgx {
-            self.dummy_variable_rgx = dummy_variable_rgx;
+    pub fn merge(&mut self, overrides: &Overrides) {
+        if let Some(dummy_variable_rgx) = &overrides.dummy_variable_rgx {
+            self.dummy_variable_rgx = dummy_variable_rgx.clone();
         }
-        if let Some(exclude) = overrides.exclude {
-            self.exclude = exclude;
+        if let Some(exclude) = &overrides.exclude {
+            self.exclude = exclude.clone();
         }
-        if let Some(extend_exclude) = overrides.extend_exclude {
-            self.extend_exclude = extend_exclude;
+        if let Some(extend_exclude) = &overrides.extend_exclude {
+            self.extend_exclude = extend_exclude.clone();
         }
-        if let Some(extend_ignore) = overrides.extend_ignore {
-            self.extend_ignore = extend_ignore;
+        if let Some(extend_ignore) = &overrides.extend_ignore {
+            self.extend_ignore = extend_ignore.clone();
         }
-        if let Some(extend_select) = overrides.extend_select {
-            self.extend_select = extend_select;
+        if let Some(extend_select) = &overrides.extend_select {
+            self.extend_select = extend_select.clone();
         }
-        if let Some(fix) = overrides.fix {
-            self.fix = fix;
+        if let Some(fix) = &overrides.fix {
+            self.fix = *fix;
         }
-        if let Some(fixable) = overrides.fixable {
-            self.fixable = fixable;
+        if let Some(fixable) = &overrides.fixable {
+            self.fixable = fixable.clone();
         }
-        if let Some(format) = overrides.format {
-            self.format = format;
+        if let Some(format) = &overrides.format {
+            self.format = *format;
         }
-        if let Some(ignore) = overrides.ignore {
-            self.ignore = ignore;
+        if let Some(ignore) = &overrides.ignore {
+            self.ignore = ignore.clone();
         }
-        if let Some(line_length) = overrides.line_length {
-            self.line_length = line_length;
+        if let Some(line_length) = &overrides.line_length {
+            self.line_length = *line_length;
         }
-        if let Some(max_complexity) = overrides.max_complexity {
-            self.mccabe.max_complexity = max_complexity;
+        if let Some(max_complexity) = &overrides.max_complexity {
+            self.mccabe.max_complexity = *max_complexity;
         }
-        if let Some(per_file_ignores) = overrides.per_file_ignores {
-            self.per_file_ignores = collect_per_file_ignores(per_file_ignores);
+        if let Some(per_file_ignores) = &overrides.per_file_ignores {
+            self.per_file_ignores = collect_per_file_ignores(per_file_ignores.clone());
         }
-        if let Some(select) = overrides.select {
-            self.select = select;
+        if let Some(select) = &overrides.select {
+            self.select = select.clone();
         }
-        if let Some(show_source) = overrides.show_source {
-            self.show_source = show_source;
+        if let Some(show_source) = &overrides.show_source {
+            self.show_source = *show_source;
         }
-        if let Some(target_version) = overrides.target_version {
-            self.target_version = target_version;
+        if let Some(target_version) = &overrides.target_version {
+            self.target_version = *target_version;
         }
-        if let Some(unfixable) = overrides.unfixable {
-            self.unfixable = unfixable;
+        if let Some(unfixable) = &overrides.unfixable {
+            self.unfixable = unfixable.clone();
         }
     }
 }

src/settings/mod.rs

@@ -55,10 +55,7 @@ pub struct Settings {
 }
 
 impl Settings {
-    pub fn from_configuration(
-        config: Configuration,
-        project_root: Option<&PathBuf>,
-    ) -> Result<Self> {
+    pub fn from_configuration(config: Configuration, project_root: Option<&Path>) -> Result<Self> {
         Ok(Self {
             allowed_confusables: config.allowed_confusables,
             dummy_variable_rgx: config.dummy_variable_rgx,
@@ -90,7 +87,7 @@ impl Settings {
             pep8_naming: config.pep8_naming,
             pyupgrade: config.pyupgrade,
             per_file_ignores: resolve_per_file_ignores(config.per_file_ignores, project_root)?,
-            src: config.src,
+            src: resolve_src(config.src, project_root),
             target_version: config.target_version,
             show_source: config.show_source,
         })
@@ -192,10 +189,7 @@ impl Hash for Settings {
 }
 
 /// Given a list of patterns, create a `GlobSet`.
-pub fn resolve_globset(
-    patterns: Vec<FilePattern>,
-    project_root: Option<&PathBuf>,
-) -> Result<GlobSet> {
+pub fn resolve_globset(patterns: Vec<FilePattern>, project_root: Option<&Path>) -> Result<GlobSet> {
     let mut builder = globset::GlobSetBuilder::new();
     for pattern in patterns {
         pattern.add_to(&mut builder, project_root)?;
@@ -206,7 +200,7 @@ pub fn resolve_globset(
 /// Given a list of patterns, create a `GlobSet`.
 pub fn resolve_per_file_ignores(
     per_file_ignores: Vec<PerFileIgnore>,
-    project_root: Option<&PathBuf>,
+    project_root: Option<&Path>,
 ) -> Result<Vec<(GlobMatcher, GlobMatcher, FxHashSet<CheckCode>)>> {
     per_file_ignores
         .into_iter()
@@ -227,6 +221,15 @@ pub fn resolve_per_file_ignores(
         .collect()
 }
 
+pub fn resolve_src(src: Vec<PathBuf>, project_root: Option<&Path>) -> Vec<PathBuf> {
+    src.into_iter()
+        .map(|path| match project_root {
+            Some(project_root) => fs::normalize_path_to(&path, project_root),
+            None => fs::normalize_path(&path),
+        })
+        .collect()
+}
+
 /// Given a set of selected and ignored prefixes, resolve the set of enabled
 /// error codes.
 fn resolve_codes(select: &[CheckCodePrefix], ignore: &[CheckCodePrefix]) -> FxHashSet<CheckCode> {

src/settings/pyproject.rs

@@ -4,7 +4,6 @@ use std::path::{Path, PathBuf};
 
 use anyhow::{anyhow, Result};
 use common_path::common_path_all;
-use log::debug;
 use path_absolutize::Absolutize;
 use serde::{Deserialize, Serialize};
 
@@ -80,18 +79,12 @@ pub fn find_project_root(sources: &[PathBuf]) -> Option<PathBuf> {
     None
 }
 
-pub fn load_options(pyproject: Option<&PathBuf>) -> Result<Options> {
-    if let Some(pyproject) = pyproject {
+pub fn load_options(pyproject: &Path) -> Result<Options> {
     Ok(parse_pyproject_toml(pyproject)
         .map_err(|err| anyhow!("Failed to parse `{}`: {}", pyproject.to_string_lossy(), err))?
         .tool
         .and_then(|tool| tool.ruff)
         .unwrap_or_default())
-    } else {
-        debug!("No pyproject.toml found.");
-        debug!("Falling back to default configuration...");
-        Ok(Options::default())
-    }
 }
 
 #[cfg(test)]

src/settings/types.rs

@@ -1,6 +1,6 @@
 use std::env;
 use std::hash::Hash;
-use std::path::{Path, PathBuf};
+use std::path::Path;
 use std::str::FromStr;
 
 use anyhow::{anyhow, bail, Result};
@@ -53,11 +53,7 @@ pub enum FilePattern {
 }
 
 impl FilePattern {
-    pub fn add_to(
-        self,
-        builder: &mut GlobSetBuilder,
-        project_root: Option<&PathBuf>,
-    ) -> Result<()> {
+    pub fn add_to(self, builder: &mut GlobSetBuilder, project_root: Option<&Path>) -> Result<()> {
         match self {
             FilePattern::Builtin(pattern) => {
                 builder.add(Glob::from_str(pattern)?);

test_project/examples/docs_snippets/docs_snippets/celery_job.py

@@ -0,0 +1,5 @@
+import os
+
+
+def f():
+    x = 1

test_project/examples/docs_snippets/docs_snippets/concepts/ignore.py

@@ -0,0 +1,5 @@
+import os
+
+
+def f():
+    x = 1

test_project/examples/docs_snippets/pyproject.toml

@@ -0,0 +1,4 @@
+[tool.ruff]
+src = ["docs_snippets"]
+extend-ignore = ["F401"]
+extend-exclude = ["./docs_snippets/concepts/ignore.py"]

test_project/pyproject.toml

@@ -0,0 +1,2 @@
+[tool.ruff]
+src = ["src"]

test_project/src/core.py

@@ -0,0 +1,5 @@
+import os
+
+
+def f():
+    x = 1