fix: pass --timeout to CLI instead of unreliable Promise.race

Promise.race rejected the promise but left the subprocess running.
The CLI now enforces the deadline via context cancellation, which
exits cleanly and propagates the timeout error through getExecOutput.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: greynewell

dist/index.js

@@ -30054,14 +30054,15 @@ async function runDeadCodeAnalysis(opts) {
     for (const pattern of opts.ignorePatterns) {
         args.push('--ignore', pattern);
     }
+    // Let the CLI enforce the timeout via context deadline so the process exits cleanly.
+    if (opts.timeoutSeconds > 0) {
+        args.push('--timeout', String(opts.timeoutSeconds));
+    }
     core.info(`Running: supermodel ${args.join(' ')}`);
-    // Wrap in a timeout promise since @actions/exec does not expose a timeout option.
-    const execPromise = exec.getExecOutput('supermodel', args, {
+    const { stdout } = await exec.getExecOutput('supermodel', args, {
         env: processEnv({ SUPERMODEL_API_KEY: opts.apiKey }),
         ignoreReturnCode: false,
     });
-    const timeoutPromise = new Promise((_, reject) => setTimeout(() => reject(new Error(`Analysis timed out after ${opts.timeoutSeconds}s`)), opts.timeoutSeconds * 1000));
-    const { stdout } = await Promise.race([execPromise, timeoutPromise]);
     return JSON.parse(stdout.trim());
 }
 async function getChangedFiles(token) {

src/index.ts

@@ -40,23 +40,18 @@ async function runDeadCodeAnalysis(opts: {
     args.push('--ignore', pattern);
   }
 
+  // Let the CLI enforce the timeout via context deadline so the process exits cleanly.
+  if (opts.timeoutSeconds > 0) {
+    args.push('--timeout', String(opts.timeoutSeconds));
+  }
+
   core.info(`Running: supermodel ${args.join(' ')}`);
 
-  // Wrap in a timeout promise since @actions/exec does not expose a timeout option.
-  const execPromise = exec.getExecOutput('supermodel', args, {
+  const { stdout } = await exec.getExecOutput('supermodel', args, {
     env: processEnv({ SUPERMODEL_API_KEY: opts.apiKey }),
     ignoreReturnCode: false,
   });
 
-  const timeoutPromise = new Promise<never>((_, reject) =>
-    setTimeout(
-      () => reject(new Error(`Analysis timed out after ${opts.timeoutSeconds}s`)),
-      opts.timeoutSeconds * 1000
-    )
-  );
-
-  const { stdout } = await Promise.race([execPromise, timeoutPromise]);
-
   return JSON.parse(stdout.trim()) as DeadCodeResult;
 }