From ab6bb6aa649b60c5daeb378bda697334558cb11f Mon Sep 17 00:00:00 2001
From: Jo <10510431+j178@users.noreply.github.com>
Date: Mon, 27 Oct 2025 17:43:12 +0800
Subject: [PATCH] Add a warning for unimplemented hooks (#976)

---
 .pre-commit-config.yaml          |  2 +-
 src/cli/run/run.rs               | 68 +++++++++++++++++++++++++++-----
 tests/languages/unimplemented.rs |  6 ++-
 3 files changed, 64 insertions(+), 12 deletions(-)

diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 526c703a..7e2e4a03 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -23,7 +23,7 @@ repos:
       - id: cargo-fmt
         name: cargo fmt
         entry: cargo fmt --
-        language: system
+        language: perl
         types: [rust]
         pass_filenames: false # This makes it a lot faster
 
diff --git a/src/cli/run/run.rs b/src/cli/run/run.rs
index 03ae737d..9cebc3fc 100644
--- a/src/cli/run/run.rs
+++ b/src/cli/run/run.rs
@@ -23,13 +23,13 @@ use crate::cli::run::{CollectOptions, FileFilter, Selectors, collect_files};
 use crate::cli::{ExitStatus, RunExtraArgs};
 use crate::config::{Language, Stage};
 use crate::fs::CWD;
-use crate::git;
 use crate::git::GIT_ROOT;
 use crate::hook::{Hook, InstallInfo, InstalledHook};
 use crate::printer::{Printer, Stdout};
 use crate::run::{CONCURRENCY, USE_COLOR};
 use crate::store::Store;
 use crate::workspace::{Project, Workspace};
+use crate::{git, warn_user};
 
 #[allow(clippy::too_many_arguments, clippy::fn_params_excessive_bools)]
 pub(crate) async fn run(
@@ -558,6 +558,7 @@ async fn run_hooks(
     let projects_len = project_to_hooks.len();
     let mut first = true;
     let mut file_modified = false;
+    let mut has_unimplemented = false;
 
     // Hooks might modify the files, so they must be run sequentially.
     'outer: for (_, mut hooks) in project_to_hooks {
@@ -584,18 +585,28 @@ async fn run_hooks(
             filter.len()
         );
 
-        let mut hook_succeed;
         for hook in hooks {
-            (hook_succeed, diff, file_modified) =
-                run_hook(hook, &filter, store, diff, verbose, dry_run, &printer).await?;
+            let result = run_hook(hook, &filter, store, diff, verbose, dry_run, &printer).await?;
+            diff = result.new_diff;
+            file_modified |= result.file_modified;
+            has_unimplemented |= result.status.is_unimplemented();
 
-            success &= hook_succeed;
+            success &= result.status.as_bool();
             if !success && (fail_fast || hook.fail_fast) {
                 break 'outer;
             }
         }
     }
 
+    if has_unimplemented {
+        warn_user!(
+            "Some hooks were skipped because their languages are unimplemented.\nWe're working hard to support more languages. Check out current support status at {}.",
+            "https://prek.j178.dev/todo/#language-support-status"
+                .cyan()
+                .underline()
+        );
+    }
+
     if !success && show_diff_on_failure && file_modified {
         if EnvVars::is_set(EnvVars::CI) {
             writeln!(
@@ -647,6 +658,33 @@ fn shuffle<T>(filenames: &mut [T]) {
     filenames.shuffle(&mut rng);
 }
 
+enum RunStatus {
+    Success,
+    Failed,
+    Skipped,
+    Unimplemented,
+}
+
+impl RunStatus {
+    fn from_bool(success: bool) -> Self {
+        if success { Self::Success } else { Self::Failed }
+    }
+
+    fn as_bool(&self) -> bool {
+        matches!(self, Self::Success | Self::Skipped | Self::Unimplemented)
+    }
+
+    fn is_unimplemented(&self) -> bool {
+        matches!(self, Self::Unimplemented)
+    }
+}
+
+struct RunResult {
+    status: RunStatus,
+    new_diff: Vec<u8>,
+    file_modified: bool,
+}
+
 async fn run_hook(
     hook: &InstalledHook,
     filter: &FileFilter<'_>,
@@ -655,7 +693,7 @@ async fn run_hook(
     verbose: bool,
     dry_run: bool,
     printer: &StatusPrinter,
-) -> Result<(bool, Vec<u8>, bool)> {
+) -> Result<RunResult> {
     let mut filenames = filter.for_hook(hook);
     trace!(
         "Files for hook `{}` after filtered: {}",
@@ -669,7 +707,11 @@ async fn run_hook(
             StatusPrinter::NO_FILES,
             Style::new().black().on_cyan(),
         )?;
-        return Ok((true, diff, false));
+        return Ok(RunResult {
+            status: RunStatus::Skipped,
+            new_diff: diff,
+            file_modified: false,
+        });
     }
 
     if !Language::supported(hook.language) {
@@ -678,7 +720,11 @@ async fn run_hook(
             StatusPrinter::UNIMPLEMENTED,
             Style::new().black().on_yellow(),
         )?;
-        return Ok((true, diff, false));
+        return Ok(RunResult {
+            status: RunStatus::Unimplemented,
+            new_diff: diff,
+            file_modified: false,
+        });
     }
 
     printer.write_running(&hook.name, false)?;
@@ -774,5 +820,9 @@ async fn run_hook(
         }
     }
 
-    Ok((success, new_diff, file_modified))
+    Ok(RunResult {
+        status: RunStatus::from_bool(success),
+        new_diff,
+        file_modified,
+    })
 }
diff --git a/tests/languages/unimplemented.rs b/tests/languages/unimplemented.rs
index 5ce49209..0731f932 100644
--- a/tests/languages/unimplemented.rs
+++ b/tests/languages/unimplemented.rs
@@ -16,12 +16,14 @@ fn unimplemented_language() {
 
     context.git_add(".");
 
-    cmd_snapshot!(context.filters(), context.run(), @r#"
+    cmd_snapshot!(context.filters(), context.run(), @r"
     success: true
     exit_code: 0
     ----- stdout -----
     rust-hook............................................(unimplemented yet)Skipped
 
     ----- stderr -----
-    "#);
+    warning: Some hooks were skipped because their languages are unimplemented.
+    We're working hard to support more languages. Check out current support status at https://prek.j178.dev/todo/#language-support-status.
+    ");
 }