Lintcheck: Fix lintcheck --fix

Author: xFrednet

lintcheck/src/config.rs

@@ -30,8 +30,13 @@ pub(crate) struct LintcheckConfig {
     /// Only process a single crate on the list
     #[clap(long, value_name = "CRATE")]
     pub only: Option<String>,
-    /// Runs cargo clippy --fix and checks if all suggestions apply
-    #[clap(long, conflicts_with("max_jobs"))]
+    /// Runs cargo clippy --fix and checks if all suggestions apply.
+    #[clap(
+        long,
+        conflicts_with("max_jobs"),
+        conflicts_with("warn_all"),
+        conflicts_with("recursive")
+    )]
     pub fix: bool,
     /// Apply a filter to only collect specified lints, this also overrides `allow` attributes
     #[clap(long = "filter", value_name = "clippy_lint_name", use_value_delimiter = true)]

lintcheck/src/input.rs

@@ -180,7 +180,7 @@ impl CrateWithSource {
     /// copies a local folder
     #[expect(clippy::too_many_lines)]
     fn download_and_extract(&self) -> Crate {
-        #[allow(clippy::result_large_err)]
+        #[expect(clippy::result_large_err)]
         fn get(path: &str) -> Result<ureq::Response, ureq::Error> {
             const MAX_RETRIES: u8 = 4;
             let mut retries = 0;

lintcheck/src/main.rs

@@ -116,11 +116,36 @@ impl Crate {
         clippy_args.extend(lint_levels_args.iter().map(String::as_str));
 
         let mut cmd = Command::new("cargo");
-        cmd.arg(if config.fix { "fix" } else { "check" })
-            .arg("--quiet")
+
+        if config.fix {
+            cmd.arg("fix");
+            cmd.arg("--allow-no-vcs");
+            // Fix should never be run in combination with `--recursive`. This
+            // should never happen as the CLI flags conflict, but you know life.
+            assert!(
+                server.is_none(),
+                "--fix was combined with `--recursive`. Server: {server:#?}"
+            );
+        } else {
+            cmd.arg("check");
+            cmd.arg("--message-format=json");
+        }
+
+        // It turns out that `cargo fix` by default runs all tests, benchmarks,
+        // and examples. This is different from `cargo check` which only runs the
+        // main packages. The `--tests` works for both `cargo fix` and `cargo check`
+        // to indicate that only the main packages and tests should be processed.
+        // This unifies the behavior between the different lintcheck modes.
+        //
+        // It also makes sense to include tests either way, since some Clippy lints
+        // have custom behavior in test code.
+        cmd.arg("--tests");
+
+        cmd.arg("--quiet")
             .current_dir(&self.path)
             .env("CLIPPY_ARGS", clippy_args.join("__CLIPPY_HACKERY__"));
 
+        // This is only used for `--recursive`
         if let Some(server) = server {
             // `cargo clippy` is a wrapper around `cargo check` that mainly sets `RUSTC_WORKSPACE_WRAPPER` to
             // `clippy-driver`. We do the same thing here with a couple changes:
@@ -145,10 +170,6 @@ impl Crate {
             return Vec::new();
         };
 
-        if !config.fix {
-            cmd.arg("--message-format=json");
-        }
-
         let shared_target_dir = shared_target_dir(&format!("_{thread_index:?}"));
         let all_output = cmd
             // use the looping index to create individual target dirs

lintcheck/src/recursive.rs

@@ -79,6 +79,7 @@ fn process_stream(
     }
 }
 
+#[derive(Debug)]
 pub(crate) struct LintcheckServer {
     pub local_addr: SocketAddr,
     receiver: Receiver<ClippyWarning>,