Add ArgGroup for --diff, --fix-only, --fix

crates/ruff_cli/src/args.rs

@@ -77,6 +77,10 @@ pub enum Command {
 // The `Parser` derive is for ruff_dev, for ruff_cli `Args` would be sufficient
 #[derive(Clone, Debug, clap::Parser)]
 #[allow(clippy::struct_excessive_bools, clippy::module_name_repetitions)]
+#[clap(group = clap::ArgGroup::new("fix_args")
+       .required(false)
+       .multiple(false)
+       .args(&["fix", "diff", "fix_only"]))]
 pub struct CheckArgs {
     /// List of files or directories to check.
     pub files: Vec<PathBuf>,
@@ -193,7 +197,7 @@ pub struct CheckArgs {
     pub extend_exclude: Option<Vec<FilePattern>>,
     /// Attempt to automatically fix both safe and unsafe lint violations. Only applicable when
     /// autofix itself is enabled (e.g., via `--fix`).
-    #[arg(long, requires("fix"))]
+    #[arg(long, requires("fix_args"))]
     pub r#unsafe: bool,
     /// List of rule codes to treat as eligible for autofix. Only applicable
     /// when autofix itself is enabled (e.g., via `--fix`).

crates/ruff_cli/tests/integration_test.rs

@@ -350,7 +350,7 @@ fn unreadable_dir() -> Result<()> {
 }
 
 #[test]
-fn different_safety_levels() -> Result<()> {
+fn display_different_safety_levels() -> Result<()> {
     let mut cmd = Command::cargo_bin(BIN_NAME)?;
 
     // `--fix` should only apply safe fixes, but should tell the user about `--fix --unsafe` if
@@ -381,7 +381,7 @@ Found 2 errors.
 }
 
 #[test]
-fn only_unsafe_fixes_remain() -> Result<()> {
+fn display_unsafe_fixes_remain() -> Result<()> {
     let mut cmd = Command::cargo_bin(BIN_NAME)?;
 
     let output = cmd
@@ -401,7 +401,7 @@ Found 1 error.
 }
 
 #[test]
-fn applies_safe_fixes_only() -> Result<()> {
+fn fix_applies_safe_fixes_only() -> Result<()> {
     let mut cmd = Command::cargo_bin(BIN_NAME)?;
 
     // `--fix` should only apply safe fixes. Since we're runnnig in `stdin` mode, output shouldn't
@@ -428,7 +428,7 @@ fn applies_safe_fixes_only() -> Result<()> {
 }
 
 #[test]
-fn applies_all_fixes() -> Result<()> {
+fn fix_applies_all_fixes() -> Result<()> {
     let mut cmd = Command::cargo_bin(BIN_NAME)?;
 
     // `--fix --unsafe` should apply both safe and unsafe fixes.
@@ -453,3 +453,120 @@ fn applies_all_fixes() -> Result<()> {
 
     Ok(())
 }
+
+#[test]
+fn diff_diffs_all_fixes() -> Result<()> {
+    let mut cmd = Command::cargo_bin(BIN_NAME)?;
+
+    // `--fix --unsafe` should apply both safe and unsafe fixes.
+    let output = cmd
+        .args([
+            "-",
+            "--format",
+            "text",
+            "--isolated",
+            "--select",
+            "F601,UP034",
+            "--diff",
+            "--unsafe",
+        ])
+        .write_stdin("x = {'a': 1, 'a': 1}\nprint(('foo'))\n")
+        .assert()
+        .failure();
+    assert_eq!(
+        str::from_utf8(&output.get_output().stdout)?,
+        r#"@@ -1,2 +1,2 @@
+-x = {'a': 1, 'a': 1}
+-print(('foo'))
++x = {'a': 1}
++print('foo')
+
+"#
+    );
+
+    Ok(())
+}
+
+#[test]
+fn diff_diffs_safe_fixes_only() -> Result<()> {
+    let mut cmd = Command::cargo_bin(BIN_NAME)?;
+
+    // `--fix --unsafe` should apply both safe and unsafe fixes.
+    let output = cmd
+        .args([
+            "-",
+            "--format",
+            "text",
+            "--isolated",
+            "--select",
+            "F601,UP034",
+            "--diff",
+        ])
+        .write_stdin("x = {'a': 1, 'a': 1}\nprint(('foo'))\n")
+        .assert()
+        .failure();
+    assert_eq!(
+        str::from_utf8(&output.get_output().stdout)?,
+        r#"@@ -1,2 +1,2 @@
+ x = {'a': 1, 'a': 1}
+-print(('foo'))
++print('foo')
+
+"#
+    );
+
+    Ok(())
+}
+
+#[test]
+fn fix_only_applies_all_fixes() -> Result<()> {
+    let mut cmd = Command::cargo_bin(BIN_NAME)?;
+
+    // `--fix --unsafe` should apply both safe and unsafe fixes.
+    let output = cmd
+        .args([
+            "-",
+            "--format",
+            "text",
+            "--isolated",
+            "--select",
+            "F601,UP034",
+            "--fix-only",
+            "--unsafe",
+        ])
+        .write_stdin("x = {'a': 1, 'a': 1}\nprint(('foo'))\n")
+        .assert()
+        .success();
+    assert_eq!(
+        str::from_utf8(&output.get_output().stdout)?,
+        "x = {'a': 1}\nprint('foo')\n"
+    );
+
+    Ok(())
+}
+
+#[test]
+fn fix_only_applies_safe_fixes_only() -> Result<()> {
+    let mut cmd = Command::cargo_bin(BIN_NAME)?;
+
+    // `--fix --unsafe` should apply both safe and unsafe fixes.
+    let output = cmd
+        .args([
+            "-",
+            "--format",
+            "text",
+            "--isolated",
+            "--select",
+            "F601,UP034",
+            "--fix-only",
+        ])
+        .write_stdin("x = {'a': 1, 'a': 1}\nprint(('foo'))\n")
+        .assert()
+        .success();
+    assert_eq!(
+        str::from_utf8(&output.get_output().stdout)?,
+        "x = {'a': 1, 'a': 1}\nprint('foo')\n"
+    );
+
+    Ok(())
+}