Update ruff check and ruff format to default to the current directory (#8791)

Closes https://github.com/astral-sh/ruff/issues/7347
Closes #3970 via use of `include`

We could update examples in our documentation, but I worry since we do
not have versioned documentation users on older versions would be
confused. Instead, I'll open an issue to track updating use of `ruff
check .` in the documentation sometime in the future.

crates/ruff_cli/resources/test/fixtures/include-test/nested-project/pyproject.toml

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

crates/ruff_cli/resources/test/fixtures/include-test/pyproject.toml

@@ -0,0 +1,2 @@
+[tool.ruff]
+include = ["a.py", "subdirectory/c.py"]

crates/ruff_cli/src/args.rs

@@ -88,6 +88,7 @@ pub enum Command {
 #[allow(clippy::struct_excessive_bools)]
 pub struct CheckCommand {
     /// List of files or directories to check.
+    #[clap(help = "List of files or directories to check [default: .]")]
     pub files: Vec<PathBuf>,
     /// Apply fixes to resolve lint violations.
     /// Use `--no-fix` to disable or `--unsafe-fixes` to include unsafe fixes.
@@ -363,6 +364,7 @@ pub struct CheckCommand {
 #[allow(clippy::struct_excessive_bools)]
 pub struct FormatCommand {
     /// List of files or directories to format.
+    #[clap(help = "List of files or directories to format [default: .]")]
     pub files: Vec<PathBuf>,
     /// Avoid writing any formatted files back; instead, exit with a non-zero status code if any
     /// files would have been modified, and zero otherwise.

crates/ruff_cli/src/commands/format.rs

@@ -34,7 +34,7 @@ use crate::args::{CliOverrides, FormatArguments};
 use crate::cache::{Cache, FileCacheKey, PackageCacheMap, PackageCaches};
 use crate::panic::{catch_unwind, PanicError};
 use crate::resolve::resolve;
-use crate::ExitStatus;
+use crate::{resolve_default_files, ExitStatus};
 
 #[derive(Debug, Copy, Clone, is_macro::Is)]
 pub(crate) enum FormatMode {
@@ -60,7 +60,7 @@ impl FormatMode {
 
 /// Format a set of files, and return the exit status.
 pub(crate) fn format(
-    cli: &FormatArguments,
+    cli: FormatArguments,
     overrides: &CliOverrides,
     log_level: LogLevel,
 ) -> Result<ExitStatus> {
@@ -70,8 +70,9 @@ pub(crate) fn format(
         overrides,
         cli.stdin_filename.as_deref(),
     )?;
-    let mode = FormatMode::from_cli(cli);
-    let (paths, resolver) = python_files_in_path(&cli.files, &pyproject_config, overrides)?;
+    let mode = FormatMode::from_cli(&cli);
+    let files = resolve_default_files(cli.files, false);
+    let (paths, resolver) = python_files_in_path(&files, &pyproject_config, overrides)?;
 
     if paths.is_empty() {
         warn_user_once!("No Python files found under the given path(s)");

crates/ruff_cli/src/lib.rs

@@ -101,6 +101,19 @@ fn is_stdin(files: &[PathBuf], stdin_filename: Option<&Path>) -> bool {
     file == Path::new("-")
 }
 
+/// Returns the default set of files if none are provided, otherwise returns `None`.
+fn resolve_default_files(files: Vec<PathBuf>, is_stdin: bool) -> Vec<PathBuf> {
+    if files.is_empty() {
+        if is_stdin {
+            vec![Path::new("-").to_path_buf()]
+        } else {
+            vec![Path::new(".").to_path_buf()]
+        }
+    } else {
+        files
+    }
+}
+
 /// Get the actual value of the `format` desired from either `output_format`
 /// or `format`, and warn the user if they're using the deprecated form.
 fn resolve_help_output_format(output_format: HelpFormat, format: Option<HelpFormat>) -> HelpFormat {
@@ -196,7 +209,7 @@ fn format(args: FormatCommand, log_level: LogLevel) -> Result<ExitStatus> {
     if is_stdin(&cli.files, cli.stdin_filename.as_deref()) {
         commands::format_stdin::format_stdin(&cli, &overrides)
     } else {
-        commands::format::format(&cli, &overrides, log_level)
+        commands::format::format(cli, &overrides, log_level)
     }
 }
 
@@ -222,17 +235,15 @@ pub fn check(args: CheckCommand, log_level: LogLevel) -> Result<ExitStatus> {
     };
     let stderr_writer = Box::new(BufWriter::new(io::stderr()));
 
+    let is_stdin = is_stdin(&cli.files, cli.stdin_filename.as_deref());
+    let files = resolve_default_files(cli.files, is_stdin);
+
     if cli.show_settings {
-        commands::show_settings::show_settings(
-            &cli.files,
-            &pyproject_config,
-            &overrides,
-            &mut writer,
-        )?;
+        commands::show_settings::show_settings(&files, &pyproject_config, &overrides, &mut writer)?;
         return Ok(ExitStatus::Success);
     }
     if cli.show_files {
-        commands::show_files::show_files(&cli.files, &pyproject_config, &overrides, &mut writer)?;
+        commands::show_files::show_files(&files, &pyproject_config, &overrides, &mut writer)?;
         return Ok(ExitStatus::Success);
     }
 
@@ -295,8 +306,7 @@ pub fn check(args: CheckCommand, log_level: LogLevel) -> Result<ExitStatus> {
         if !fix_mode.is_generate() {
             warn_user!("--fix is incompatible with --add-noqa.");
         }
-        let modifications =
-            commands::add_noqa::add_noqa(&cli.files, &pyproject_config, &overrides)?;
+        let modifications = commands::add_noqa::add_noqa(&files, &pyproject_config, &overrides)?;
         if modifications > 0 && log_level >= LogLevel::Default {
             let s = if modifications == 1 { "" } else { "s" };
             #[allow(clippy::print_stderr)]
@@ -323,7 +333,7 @@ pub fn check(args: CheckCommand, log_level: LogLevel) -> Result<ExitStatus> {
         // Configure the file watcher.
         let (tx, rx) = channel();
         let mut watcher = recommended_watcher(tx)?;
-        for file in &cli.files {
+        for file in &files {
             watcher.watch(file, RecursiveMode::Recursive)?;
         }
         if let Some(file) = pyproject_config.path.as_ref() {
@@ -335,7 +345,7 @@ pub fn check(args: CheckCommand, log_level: LogLevel) -> Result<ExitStatus> {
         printer.write_to_user("Starting linter in watch mode...\n");
 
         let messages = commands::check::check(
-            &cli.files,
+            &files,
             &pyproject_config,
             &overrides,
             cache.into(),
@@ -368,7 +378,7 @@ pub fn check(args: CheckCommand, log_level: LogLevel) -> Result<ExitStatus> {
                     printer.write_to_user("File change detected...\n");
 
                     let messages = commands::check::check(
-                        &cli.files,
+                        &files,
                         &pyproject_config,
                         &overrides,
                         cache.into(),
@@ -382,8 +392,6 @@ pub fn check(args: CheckCommand, log_level: LogLevel) -> Result<ExitStatus> {
             }
         }
     } else {
-        let is_stdin = is_stdin(&cli.files, cli.stdin_filename.as_deref());
-
         // Generate lint violations.
         let diagnostics = if is_stdin {
             commands::check_stdin::check_stdin(
@@ -395,7 +403,7 @@ pub fn check(args: CheckCommand, log_level: LogLevel) -> Result<ExitStatus> {
             )?
         } else {
             commands::check::check(
-                &cli.files,
+                &files,
                 &pyproject_config,
                 &overrides,
                 cache.into(),

crates/ruff_cli/tests/format.rs

@@ -43,6 +43,53 @@ if condition:
     "###);
 }
 
+#[test]
+fn default_files() -> Result<()> {
+    let tempdir = TempDir::new()?;
+    fs::write(
+        tempdir.path().join("foo.py"),
+        r#"
+foo =     "needs formatting"
+"#,
+    )?;
+    fs::write(
+        tempdir.path().join("bar.py"),
+        r#"
+bar =     "needs formatting"
+"#,
+    )?;
+
+    assert_cmd_snapshot!(Command::new(get_cargo_bin(BIN_NAME))
+        .args(["format", "--isolated", "--no-cache", "--check"]).current_dir(tempdir.path()), @r###"
+    success: false
+    exit_code: 1
+    ----- stdout -----
+    Would reformat: bar.py
+    Would reformat: foo.py
+    2 files would be reformatted
+
+    ----- stderr -----
+    "###);
+
+    Ok(())
+}
+
+#[test]
+fn format_warn_stdin_filename_with_files() {
+    assert_cmd_snapshot!(Command::new(get_cargo_bin(BIN_NAME))
+        .args(["format", "--stdin-filename", "foo.py"])
+        .arg("foo.py")
+        .pass_stdin("foo =     1"), @r###"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+    foo = 1
+
+    ----- stderr -----
+    warning: Ignoring file foo.py in favor of standard input.
+    "###);
+}
+
 #[test]
 fn format_options() -> Result<()> {
     let tempdir = TempDir::new()?;

crates/ruff_cli/tests/integration_test.rs

@@ -74,6 +74,57 @@ fn stdin_filename() {
     "###);
 }
 
+#[test]
+fn check_default_files() -> Result<()> {
+    let tempdir = TempDir::new()?;
+    fs::write(
+        tempdir.path().join("foo.py"),
+        r#"
+import foo   # unused import
+"#,
+    )?;
+    fs::write(
+        tempdir.path().join("bar.py"),
+        r#"
+import bar   # unused import
+"#,
+    )?;
+
+    assert_cmd_snapshot!(Command::new(get_cargo_bin(BIN_NAME))
+        .args(["check", "--isolated", "--no-cache", "--select", "F401"]).current_dir(tempdir.path()), @r###"
+    success: false
+    exit_code: 1
+    ----- stdout -----
+    bar.py:2:8: F401 [*] `bar` imported but unused
+    foo.py:2:8: F401 [*] `foo` imported but unused
+    Found 2 errors.
+    [*] 2 fixable with the `--fix` option.
+
+    ----- stderr -----
+    "###);
+
+    Ok(())
+}
+
+#[test]
+fn check_warn_stdin_filename_with_files() {
+    assert_cmd_snapshot!(Command::new(get_cargo_bin(BIN_NAME))
+        .args(STDIN_BASE_OPTIONS)
+        .args(["--stdin-filename", "F401.py"])
+        .arg("foo.py")
+        .pass_stdin("import os\n"), @r###"
+    success: false
+    exit_code: 1
+    ----- stdout -----
+    F401.py:1:8: F401 [*] `os` imported but unused
+    Found 1 error.
+    [*] 1 fixable with the `--fix` option.
+
+    ----- stderr -----
+    warning: Ignoring file foo.py in favor of standard input.
+    "###);
+}
+
 /// Raise `TCH` errors in `.py` files ...
 #[test]
 fn stdin_source_type_py() {
@@ -320,6 +371,7 @@ fn stdin_fix_jupyter() {
     Found 2 errors (2 fixed, 0 remaining).
     "###);
 }
+
 #[test]
 fn stdin_override_parser_ipynb() {
     let args = ["--extension", "py:ipynb", "--stdin-filename", "Jupyter.py"];

crates/ruff_cli/tests/resolve_files.rs

@@ -0,0 +1,101 @@
+#![cfg(not(target_family = "wasm"))]
+
+use std::path::Path;
+use std::process::Command;
+use std::str;
+
+use insta_cmd::{assert_cmd_snapshot, get_cargo_bin};
+const BIN_NAME: &str = "ruff";
+
+#[cfg(not(target_os = "windows"))]
+const TEST_FILTERS: &[(&str, &str)] = &[(".*/resources/test/fixtures/", "[BASEPATH]/")];
+#[cfg(target_os = "windows")]
+const TEST_FILTERS: &[(&str, &str)] = &[
+    (r".*\\resources\\test\\fixtures\\", "[BASEPATH]\\"),
+    (r"\\", "/"),
+];
+
+#[test]
+fn check_project_include_defaults() {
+    // Defaults to checking the current working directory
+    //
+    // The test directory includes:
+    //  - A pyproject.toml which specifies an include
+    //  - A nested pyproject.toml which has a Ruff section
+    //
+    // The nested project should all be checked instead of respecting the parent includes
+
+    insta::with_settings!({
+        filters => TEST_FILTERS.to_vec()
+    }, {
+        assert_cmd_snapshot!(Command::new(get_cargo_bin(BIN_NAME))
+        .args(["check", "--show-files"]).current_dir(Path::new("./resources/test/fixtures/include-test")), @r###"
+        success: true
+        exit_code: 0
+        ----- stdout -----
+        [BASEPATH]/include-test/a.py
+        [BASEPATH]/include-test/nested-project/e.py
+        [BASEPATH]/include-test/nested-project/pyproject.toml
+        [BASEPATH]/include-test/subdirectory/c.py
+
+        ----- stderr -----
+        "###);
+    });
+}
+
+#[test]
+fn check_project_respects_direct_paths() {
+    // Given a direct path not included in the project `includes`, it should be checked
+
+    insta::with_settings!({
+        filters => TEST_FILTERS.to_vec()
+    }, {
+        assert_cmd_snapshot!(Command::new(get_cargo_bin(BIN_NAME))
+        .args(["check", "--show-files", "b.py"]).current_dir(Path::new("./resources/test/fixtures/include-test")), @r###"
+        success: true
+        exit_code: 0
+        ----- stdout -----
+        [BASEPATH]/include-test/b.py
+
+        ----- stderr -----
+        "###);
+    });
+}
+
+#[test]
+fn check_project_respects_subdirectory_includes() {
+    // Given a direct path to a subdirectory, the include should be respected
+
+    insta::with_settings!({
+        filters => TEST_FILTERS.to_vec()
+    }, {
+        assert_cmd_snapshot!(Command::new(get_cargo_bin(BIN_NAME))
+        .args(["check", "--show-files", "subdirectory"]).current_dir(Path::new("./resources/test/fixtures/include-test")), @r###"
+        success: true
+        exit_code: 0
+        ----- stdout -----
+        [BASEPATH]/include-test/subdirectory/c.py
+
+        ----- stderr -----
+        "###);
+    });
+}
+
+#[test]
+fn check_project_from_project_subdirectory_respects_includes() {
+    // Run from a project subdirectory, the include specified in the parent directory should be respected
+
+    insta::with_settings!({
+        filters => TEST_FILTERS.to_vec()
+    }, {
+        assert_cmd_snapshot!(Command::new(get_cargo_bin(BIN_NAME))
+        .args(["check", "--show-files"]).current_dir(Path::new("./resources/test/fixtures/include-test/subdirectory")), @r###"
+        success: true
+        exit_code: 0
+        ----- stdout -----
+        [BASEPATH]/include-test/subdirectory/c.py
+
+        ----- stderr -----
+        "###);
+    });
+}

docs/configuration.md

@@ -299,6 +299,47 @@ By default, Ruff will also skip any files that are omitted via `.ignore`, `.giti
 Files that are passed to `ruff` directly are always analyzed, regardless of the above criteria.
 For example, `ruff check /path/to/excluded/file.py` will always lint `file.py`.
 
+### Default inclusions
+
+By default, Ruff will discover files matching `*.py`, `*.ipy`, or `pyproject.toml`. 
+
+To lint or format files with additional file extensions, use the [`extend-include`](settings.md#extend-include) setting.
+
+=== "pyproject.toml"
+
+    ```toml
+    [tool.ruff.lint]
+    extend-include = ["*.ipynb"]
+    ```
+
+=== "ruff.toml"
+
+    ```toml
+    [lint]
+    extend-include = ["*.ipynb"]
+    ```
+
+You can also change the default selection using the [`include`](settings.md#include) setting.
+
+
+=== "pyproject.toml"
+
+    ```toml
+    [tool.ruff.lint]
+    include = ["pyproject.toml", "src/**/*.py", "scripts/**/*.py"]
+    ```
+
+=== "ruff.toml"
+
+    ```toml
+    [lint]
+    include = ["pyproject.toml", "src/**/*.py", "scripts/**/*.py"]
+    ```
+
+!!! warning
+    Paths provided to `include` _must_ match files. For example, `include = ["src"]` will fail since it
+matches a directory.
+
 ## Jupyter Notebook discovery
 
 Ruff has built-in support for [Jupyter Notebooks](https://jupyter.org/).
@@ -422,7 +463,7 @@ Run Ruff on the given files or directories (default)
 Usage: ruff check [OPTIONS] [FILES]...
 
 Arguments:
-  [FILES]...  List of files or directories to check
+  [FILES]...  List of files or directories to check [default: .]
 
 Options:
       --fix
@@ -518,7 +559,7 @@ Run the Ruff formatter on the given files or directories
 Usage: ruff format [OPTIONS] [FILES]...
 
 Arguments:
-  [FILES]...  List of files or directories to format
+  [FILES]...  List of files or directories to format [default: .]
 
 Options:
       --check

docs/formatter.md

@@ -19,6 +19,10 @@ and instead exit with a non-zero status code upon detecting any unformatted file
 
 For the full list of supported options, run `ruff format --help`.
 
+!!! note
+    As of Ruff v0.1.7 the `ruff format` command uses the current working directory (`.`) as the default path to format.
+    See [the file discovery documentation](configuration.md#python-file-discovery) for details.
+
 ## Philosophy
 
 The initial goal of the Ruff formatter is _not_ to innovate on code style, but rather, to innovate

docs/linter.md

@@ -18,6 +18,10 @@ ruff check . --watch  # Lint all files in the current directory, and re-lint on
 
 For the full list of supported options, run `ruff check --help`.
 
+!!! note
+    As of Ruff v0.1.7 the `ruff check` command uses the current working directory (`.`) as the default path to check.
+    See [the file discovery documentation](configuration.md#python-file-discovery) for details.
+
 ## Rule selection
 
 The set of enabled rules is controlled via the [`select`](settings.md#select),