Include fixes in JSON API output (#988)

src/main.rs

@@ -37,6 +37,7 @@ use log::{debug, error};
 use notify::{raw_watcher, RecursiveMode, Watcher};
 #[cfg(not(target_family = "wasm"))]
 use rayon::prelude::*;
+use ruff::autofix::fixer;
 use rustpython_ast::Location;
 use walkdir::DirEntry;
 
@@ -60,14 +61,23 @@ fn read_from_stdin() -> Result<String> {
     Ok(buffer)
 }
 
-fn run_once_stdin(settings: &Settings, filename: &Path, autofix: bool) -> Result<Diagnostics> {
+fn run_once_stdin(
+    settings: &Settings,
+    filename: &Path,
+    autofix: &fixer::Mode,
+) -> Result<Diagnostics> {
     let stdin = read_from_stdin()?;
-    let mut diagnostics = lint_stdin(filename, &stdin, settings, &autofix.into())?;
+    let mut diagnostics = lint_stdin(filename, &stdin, settings, autofix)?;
     diagnostics.messages.sort_unstable();
     Ok(diagnostics)
 }
 
-fn run_once(files: &[PathBuf], settings: &Settings, cache: bool, autofix: bool) -> Diagnostics {
+fn run_once(
+    files: &[PathBuf],
+    settings: &Settings,
+    cache: bool,
+    autofix: &fixer::Mode,
+) -> Diagnostics {
     // Collect all the files to check.
     let start = Instant::now();
     let paths: Vec<Result<DirEntry, walkdir::Error>> = files
@@ -83,7 +93,7 @@ fn run_once(files: &[PathBuf], settings: &Settings, cache: bool, autofix: bool)
             match entry {
                 Ok(entry) => {
                     let path = entry.path();
-                    lint_path(path, settings, &cache.into(), &autofix.into())
+                    lint_path(path, settings, &cache.into(), autofix)
                         .map_err(|e| (Some(path.to_owned()), e.to_string()))
                 }
                 Err(e) => Err((
@@ -99,6 +109,7 @@ fn run_once(files: &[PathBuf], settings: &Settings, cache: bool, autofix: bool)
                             kind: CheckKind::IOError(message),
                             location: Location::default(),
                             end_location: Location::default(),
+                            fix: None,
                             filename: path.to_string_lossy().to_string(),
                             source: None,
                         }])
@@ -266,7 +277,13 @@ fn inner_main() -> Result<ExitCode> {
     }
 
     // Extract settings for internal use.
-    let fix_enabled: bool = configuration.fix;
+    let autofix = if configuration.fix {
+        fixer::Mode::Apply
+    } else if matches!(configuration.format, SerializationFormat::Json) {
+        fixer::Mode::Generate
+    } else {
+        fixer::Mode::None
+    };
     let settings = Settings::from_configuration(configuration, project_root.as_ref())?;
 
     // Now that we've inferred the appropriate log level, add some debug
@@ -299,10 +316,7 @@ fn inner_main() -> Result<ExitCode> {
 
     let printer = Printer::new(&settings.format, &log_level);
     if cli.watch {
-        if settings.format != SerializationFormat::Text {
+        if matches!(autofix, fixer::Mode::Generate | fixer::Mode::Apply) {
-            eprintln!("Warning: --format 'text' is used in watch mode.");
-        }
-        if fix_enabled {
             eprintln!("Warning: --fix is not enabled in watch mode.");
         }
         if cli.add_noqa {
@@ -311,12 +325,15 @@ fn inner_main() -> Result<ExitCode> {
         if cli.autoformat {
             eprintln!("Warning: --autoformat is not enabled in watch mode.");
         }
+        if settings.format != SerializationFormat::Text {
+            eprintln!("Warning: --format 'text' is used in watch mode.");
+        }
 
         // Perform an initial run instantly.
         printer.clear_screen()?;
         printer.write_to_user("Starting linter in watch mode...\n");
 
-        let messages = run_once(&cli.files, &settings, cache_enabled, false);
+        let messages = run_once(&cli.files, &settings, cache_enabled, &fixer::Mode::None);
         printer.write_continuously(&messages)?;
 
         // Configure the file watcher.
@@ -334,7 +351,8 @@ fn inner_main() -> Result<ExitCode> {
                             printer.clear_screen()?;
                             printer.write_to_user("File change detected...\n");
 
-                            let messages = run_once(&cli.files, &settings, cache_enabled, false);
+                            let messages =
+                                run_once(&cli.files, &settings, cache_enabled, &fixer::Mode::None);
                             printer.write_continuously(&messages)?;
                         }
                     }
@@ -359,15 +377,15 @@ fn inner_main() -> Result<ExitCode> {
         let diagnostics = if is_stdin {
             let filename = cli.stdin_filename.unwrap_or_else(|| "-".to_string());
             let path = Path::new(&filename);
-            run_once_stdin(&settings, path, fix_enabled)?
+            run_once_stdin(&settings, path, &autofix)?
         } else {
-            run_once(&cli.files, &settings, cache_enabled, fix_enabled)
+            run_once(&cli.files, &settings, cache_enabled, &autofix)
         };
 
         // Always try to print violations (the printer itself may suppress output),
         // unless we're writing fixes via stdin (in which case, the transformed
         // source code goes to stdout).
-        if !(is_stdin && fix_enabled) {
+        if !(is_stdin && matches!(autofix, fixer::Mode::Apply)) {
             printer.write_once(&diagnostics)?;
         }
 

src/message.rs

@@ -4,6 +4,7 @@ use rustpython_parser::ast::Location;
 use serde::{Deserialize, Serialize};
 
 use crate::ast::types::Range;
+use crate::autofix::Fix;
 use crate::checks::{Check, CheckKind};
 use crate::source_code_locator::SourceCodeLocator;
 
@@ -12,6 +13,7 @@ pub struct Message {
     pub kind: CheckKind,
     pub location: Location,
     pub end_location: Location,
+    pub fix: Option<Fix>,
     pub filename: String,
     pub source: Option<Source>,
 }
@@ -22,6 +24,7 @@ impl Message {
             kind: check.kind,
             location: Location::new(check.location.row(), check.location.column() + 1),
             end_location: Location::new(check.end_location.row(), check.end_location.column() + 1),
+            fix: check.fix,
             filename,
             source,
         }

src/printer.rs

@@ -9,7 +9,8 @@ use itertools::iterate;
 use rustpython_parser::ast::Location;
 use serde::Serialize;
 
-use crate::checks::{CheckCode, CheckKind};
+use crate::autofix::Fix;
+use crate::checks::CheckCode;
 use crate::fs::relativize_path;
 use crate::linter::Diagnostics;
 use crate::logging::LogLevel;
@@ -19,9 +20,9 @@ use crate::tell_user;
 
 #[derive(Serialize)]
 struct ExpandedMessage<'a> {
-    kind: &'a CheckKind,
     code: &'a CheckCode,
     message: String,
+    fix: Option<&'a Fix>,
     location: Location,
     end_location: Location,
     filename: &'a str,
@@ -85,9 +86,9 @@ impl<'a> Printer<'a> {
                             .messages
                             .iter()
                             .map(|message| ExpandedMessage {
-                                kind: &message.kind,
                                 code: message.kind.code(),
                                 message: message.kind.body(),
+                                fix: message.fix.as_ref(),
                                 location: message.location,
                                 end_location: message.end_location,
                                 filename: &message.filename,

tests/integration_test.rs

@@ -21,7 +21,11 @@ fn test_stdin_error() -> Result<()> {
         .write_stdin("import os\n")
         .assert()
         .failure();
-    assert!(str::from_utf8(&output.get_output().stdout)?.contains("-:1:8: F401"));
+    assert_eq!(
+        str::from_utf8(&output.get_output().stdout)?,
+        "Found 1 error(s).\n-:1:8: F401 `os` imported but unused\n1 potentially fixable with the \
+         --fix option.\n"
+    );
     Ok(())
 }
 
@@ -33,7 +37,31 @@ fn test_stdin_filename() -> Result<()> {
         .write_stdin("import os\n")
         .assert()
         .failure();
-    assert!(str::from_utf8(&output.get_output().stdout)?.contains("F401.py:1:8: F401"));
+    assert_eq!(
+        str::from_utf8(&output.get_output().stdout)?,
+        "Found 1 error(s).\nF401.py:1:8: F401 `os` imported but unused\n1 potentially fixable \
+         with the --fix option.\n"
+    );
+    Ok(())
+}
+
+#[test]
+fn test_stdin_json() -> Result<()> {
+    let mut cmd = Command::cargo_bin(crate_name!())?;
+    let output = cmd
+        .args(["-", "--format", "json", "--stdin-filename", "F401.py"])
+        .write_stdin("import os\n")
+        .assert()
+        .failure();
+    assert_eq!(
+        str::from_utf8(&output.get_output().stdout)?,
+        "[\n  {\n    \"code\": \"F401\",\n    \"message\": \"`os` imported but unused\",\n    \
+         \"fix\": {\n      \"content\": \"\",\n      \"location\": {\n        \"row\": 1,\n        \
+         \"column\": 0\n      },\n      \"end_location\": {\n        \"row\": 2,\n        \
+         \"column\": 0\n      }\n    },\n    \"location\": {\n      \"row\": 1,\n      \
+         \"column\": 8\n    },\n    \"end_location\": {\n      \"row\": 1,\n      \"column\": \
+         10\n    },\n    \"filename\": \"F401.py\"\n  }\n]\n"
+    );
     Ok(())
 }