fix: preserve Apple tool cancellation

Author: thymikee

src/platform-runtime-apple-tool-host.test.ts

@@ -48,3 +48,37 @@ test('Apple tool host rejects pre-aborted requests before invoking the provider'
   });
   expect(runCommand).not.toHaveBeenCalled();
 });
+
+test('Apple tool host preserves the exact abort reason when the provider rejects differently', async () => {
+  const reason = new Error('cancelled');
+  const transportError = new Error('provider transport failed');
+  const controller = new AbortController();
+  const runCommand = vi.fn(async () => {
+    controller.abort(reason);
+    throw transportError;
+  });
+  const provider = createLocalAppleToolProvider({ runCommand });
+  const host = createAppleToolHost();
+
+  await withAppleToolProvider(provider, async () => {
+    await expect(
+      host.run({ tool: 'xctrace', args: ['list', 'devices'] }, controller.signal),
+    ).rejects.toBe(reason);
+  });
+});
+
+test('Apple tool availability preserves the exact abort reason when lookup rejects differently', async () => {
+  const reason = new Error('cancelled');
+  const transportError = new Error('provider lookup failed');
+  const controller = new AbortController();
+  const whichCommand = vi.fn(async () => {
+    controller.abort(reason);
+    throw transportError;
+  });
+  const provider = createLocalAppleToolProvider({ whichCommand });
+  const host = createAppleToolHost();
+
+  await withAppleToolProvider(provider, async () => {
+    await expect(host.isXcrunAvailable(controller.signal)).rejects.toBe(reason);
+  });
+});

src/platform-runtime-apple-tool-host.ts

@@ -3,23 +3,30 @@ import type { AppleToolHost } from '@agent-device/contracts/platform';
 export function createAppleToolHost(): AppleToolHost {
   return Object.freeze({
     isXcrunAvailable: async (signal?: AbortSignal) => {
-      signal?.throwIfAborted();
-      const { resolveAppleToolProvider } = await import('./platforms/apple/core/tool-provider.ts');
-      signal?.throwIfAborted();
-      const available = await resolveAppleToolProvider().whichCommand('xcrun');
-      signal?.throwIfAborted();
+      const { resolveAppleToolProvider } = await awaitPreservingAbortReason(
+        async () => await import('./platforms/apple/core/tool-provider.ts'),
+        signal,
+      );
+      const available = await awaitPreservingAbortReason(
+        async () => await resolveAppleToolProvider().whichCommand('xcrun'),
+        signal,
+      );
       return available;
     },
     run: async (request, signal) => {
-      signal?.throwIfAborted();
-      const { runXcrun } = await import('./platforms/apple/core/tool-provider.ts');
-      signal?.throwIfAborted();
-      const result = await runXcrun([request.tool, ...request.args], {
-        allowFailure: request.allowFailure,
+      const { runXcrun } = await awaitPreservingAbortReason(
+        async () => await import('./platforms/apple/core/tool-provider.ts'),
+        signal,
+      );
+      const result = await awaitPreservingAbortReason(
+        async () =>
+          await runXcrun([request.tool, ...request.args], {
+            allowFailure: request.allowFailure,
+            signal,
+            timeoutMs: request.timeoutMs,
+          }),
         signal,
-        timeoutMs: request.timeoutMs,
-      });
-      signal?.throwIfAborted();
+      );
       return {
         stdout: result.stdout,
         stderr: result.stderr,
@@ -28,3 +35,18 @@ export function createAppleToolHost(): AppleToolHost {
     },
   });
 }
+
+async function awaitPreservingAbortReason<T>(
+  operation: () => Promise<T>,
+  signal?: AbortSignal,
+): Promise<T> {
+  signal?.throwIfAborted();
+  try {
+    const result = await operation();
+    signal?.throwIfAborted();
+    return result;
+  } catch (error) {
+    signal?.throwIfAborted();
+    throw error;
+  }
+}