Mark fixable issues in printer output (#2500)

ruff_cli/src/printer.rs

@@ -122,7 +122,7 @@ impl<'a> Printer<'a> {
                         if num_fixable > 0 {
                             writeln!(
                                 stdout,
-                                "{num_fixable} potentially fixable with the --fix option."
+                                "[*] {num_fixable} potentially fixable with the --fix option."
                             )?;
                         }
                     }
@@ -475,7 +475,20 @@ fn num_digits(n: usize) -> usize {
 
 /// Print a single `Message` with full details.
 fn print_message<T: Write>(stdout: &mut T, message: &Message) -> Result<()> {
-    let label = format!(
+    let label = if message.kind.fixable() {
+        format!(
+            "{}{}{}{}{}{} {} [*] {}",
+            relativize_path(Path::new(&message.filename)).bold(),
+            ":".cyan(),
+            message.location.row(),
+            ":".cyan(),
+            message.location.column(),
+            ":".cyan(),
+            message.kind.rule().code().red().bold(),
+            message.kind.body(),
+        )
+    } else {
+        format!(
             "{}{}{}{}{}{} {} {}",
             relativize_path(Path::new(&message.filename)).bold(),
             ":".cyan(),
@@ -485,7 +498,8 @@ fn print_message<T: Write>(stdout: &mut T, message: &Message) -> Result<()> {
             ":".cyan(),
             message.kind.rule().code().red().bold(),
             message.kind.body(),
-    );
+        )
+    };
     writeln!(stdout, "{label}")?;
     if let Some(source) = &message.source {
         let commit = message.kind.commit();
@@ -540,7 +554,19 @@ fn print_grouped_message<T: Write>(
     row_length: usize,
     column_length: usize,
 ) -> Result<()> {
-    let label = format!(
+    let label = if message.kind.fixable() {
+        format!(
+            "  {}{}{}{}{}  {}  [*] {}",
+            " ".repeat(row_length - num_digits(message.location.row())),
+            message.location.row(),
+            ":".cyan(),
+            message.location.column(),
+            " ".repeat(column_length - num_digits(message.location.column())),
+            message.kind.rule().code().red().bold(),
+            message.kind.body(),
+        )
+    } else {
+        format!(
             "  {}{}{}{}{}  {}  {}",
             " ".repeat(row_length - num_digits(message.location.row())),
             message.location.row(),
@@ -549,7 +575,8 @@ fn print_grouped_message<T: Write>(
             " ".repeat(column_length - num_digits(message.location.column())),
             message.kind.rule().code().red().bold(),
             message.kind.body(),
-    );
+        )
+    };
     writeln!(stdout, "{label}")?;
     if let Some(source) = &message.source {
         let commit = message.kind.commit();

ruff_cli/tests/integration_test.rs

@@ -31,8 +31,10 @@ fn test_stdin_error() -> Result<()> {
         .failure();
     assert_eq!(
         str::from_utf8(&output.get_output().stdout)?,
-        "-:1:8: F401 `os` imported but unused\nFound 1 error.\n1 potentially fixable with the \
+        r#"-:1:8: F401 [*] `os` imported but unused
-         --fix option.\n"
+Found 1 error.
+[*] 1 potentially fixable with the --fix option.
+"#
     );
     Ok(())
 }
@@ -54,8 +56,10 @@ fn test_stdin_filename() -> Result<()> {
         .failure();
     assert_eq!(
         str::from_utf8(&output.get_output().stdout)?,
-        "F401.py:1:8: F401 `os` imported but unused\nFound 1 error.\n1 potentially fixable with \
+        r#"F401.py:1:8: F401 [*] `os` imported but unused
-         the --fix option.\n"
+Found 1 error.
+[*] 1 potentially fixable with the --fix option.
+"#
     );
     Ok(())
 }