fix(server): every commit hook reports finishing with its real exit code

apps/server/src/vcs/GitVcsDriverCore.test.ts

@@ -3874,6 +3874,56 @@ it.layer(layerTest)("GitVcsDriver core integration", (it) => {
       }),
     );
 
+    const commitWithHooks = (hooks: Record<string, string>) =>
+      Effect.gen(function* () {
+        const cwd = yield* makeTmpDir();
+        yield* initRepoWithCommit(cwd);
+        const fs = yield* FileSystem.FileSystem;
+        const path = yield* Path.Path;
+        for (const [name, script] of Object.entries(hooks)) {
+          yield* writeTextFile(cwd, `.git/hooks/${name}`, `#!/bin/sh\n${script}\n`);
+          yield* fs.chmod(path.join(cwd, ".git/hooks", name), 0o755);
+        }
+        yield* writeTextFile(cwd, "a.txt", "a\n");
+        const events: string[] = [];
+        const result = yield* (yield* GitVcsDriver.GitVcsDriver)
+          .commit(cwd, "Add a", "", {
+            stage: { filePaths: ["a.txt"] },
+            progress: {
+              onHookStarted: (hookName) => Effect.sync(() => void events.push(`start ${hookName}`)),
+              onHookFinished: ({ hookName, exitCode }) =>
+                Effect.sync(() => void events.push(`finish ${hookName} ${exitCode}`)),
+            },
+          })
+          .pipe(Effect.result);
+        return { events, committed: Result.isSuccess(result) };
+      });
+
+    it.effect("reports each commit hook finishing with its exit code", () =>
+      Effect.gen(function* () {
+        // The pre-commit hook runs git, whose own children reuse child_id 0 in the shared trace.
+        const { events, committed } = yield* commitWithHooks({
+          "pre-commit": "git -c alias.noop='!false' noop\nexit 0",
+          "commit-msg": "exit 0",
+        });
+        assert.isTrue(committed);
+        assert.deepEqual(events, [
+          "start pre-commit",
+          "finish pre-commit 0",
+          "start commit-msg",
+          "finish commit-msg 0",
+        ]);
+      }),
+    );
+
+    it.effect("reports the exit code of a commit hook that rejects the commit", () =>
+      Effect.gen(function* () {
+        const { events, committed } = yield* commitWithHooks({ "commit-msg": "exit 3" });
+        assert.isFalse(committed);
+        assert.deepEqual(events, ["start commit-msg", "finish commit-msg 3"]);
+      }),
+    );
+
     it.effect.each([false, true])(
       "preserves partial staging and split-index files (split: %s)",
       (split) =>

apps/server/src/vcs/GitVcsDriverCore.ts

@@ -629,10 +629,11 @@ const addCurrentSpanEvent =
     }),
   );
 
+// Nested Git processes share the trace file but reuse child IDs in their own sessions.
 function trace2ChildKey(record: Record<string, unknown>): string | null {
   const childId = record.child_id;
   if (typeof childId === "number" || typeof childId === "string") {
-    return String(childId);
+    return typeof record.sid === "string" ? `${record.sid}\n${childId}` : String(childId);
   }
   const hookName = record.hook_name;
   return typeof hookName === "string" && hookName.trim().length > 0 ? hookName.trim() : null;
@@ -683,10 +684,6 @@ const createTrace2Monitor = Effect.fnUntraced(function* (
       return;
     }
 
-    if (traceRecord.success.child_class !== "hook") {
-      return;
-    }
-
     const event = traceRecord.success.event;
     const childKey = trace2ChildKey(traceRecord.success);
     if (childKey === null) {
@@ -701,6 +698,9 @@ const createTrace2Monitor = Effect.fnUntraced(function* (
     }
 
     if (event === "child_start") {
+      if (traceRecord.success.child_class !== "hook") {
+        return;
+      }
       const now = yield* DateTime.now;
       hookStartByChildKey.set(childKey, { hookName, startedAtMs: DateTime.toEpochMillis(now) });
       yield* addCurrentSpanEvent("git.hook.started", {
@@ -712,22 +712,20 @@ const createTrace2Monitor = Effect.fnUntraced(function* (
       return;
     }
 
-    if (event === "child_exit") {
+    if (event === "child_exit" && started) {
       hookStartByChildKey.delete(childKey);
-      const code = traceRecord.success.exitCode;
+      const code = traceRecord.success.code;
       const exitCode = typeof code === "number" && Number.isInteger(code) ? code : null;
       const now = yield* DateTime.now;
-      const durationMs = started
-        ? Math.max(0, DateTime.toEpochMillis(now) - started.startedAtMs)
-        : null;
+      const durationMs = Math.max(0, DateTime.toEpochMillis(now) - started.startedAtMs);
       yield* addCurrentSpanEvent("git.hook.finished", {
-        hookName: started?.hookName ?? hookName,
+        hookName: started.hookName,
         exitCode,
         durationMs,
       });
       if (progress.onHookFinished) {
         yield* progress.onHookFinished({
-          hookName: started?.hookName ?? hookName,
+          hookName: started.hookName,
           exitCode,
           durationMs,
         });