fix: handle devicectl launch arguments (#93)

Harness uses devicectl device process launch for physical iOS devices.
When app launch arguments are present, devicectl expects them after a -- separator.
Without that separator, launch arguments are parsed incorrectly and physical-device startup can fail.

Harness also appends --json-output to every devicectl command.
That flag must stay before the -- separator so devicectl still treats it as its own option and writes the result JSON file correctly.

Author: hannojg

.nx/version-plans/fix-devicectl-launch-args.md

@@ -0,0 +1,5 @@
+---
+__default__: patch
+---
+
+Physical iOS app launches now pass Harness launch arguments to `xcrun devicectl` without breaking JSON output collection. This prevents app launch arguments from being misinterpreted as `devicectl` flags and keeps device launches working when custom arguments are provided.

packages/platform-ios/src/__tests__/launch-options.test.ts

@@ -35,6 +35,7 @@ describe('Apple app launch options', () => {
       '--environment-variables',
       '{"FEATURE_X":"1"}',
       'com.example.app',
+      '--',
       '--mode=test',
       '--retry=1',
     ]);

packages/platform-ios/src/xcrun/devicectl.ts

@@ -10,15 +10,27 @@ export const devicectl = async <TOutput>(
   args: string[]
 ): Promise<TOutput> => {
   const tempFile = join(tmpdir(), `devicectl-${randomUUID()}.json`);
+  const separatorIndex = args.indexOf('--');
+  const argsWithJsonOutput =
+    separatorIndex === -1
+      ? [...args, '--json-output', tempFile]
+      : [
+          ...args.slice(0, separatorIndex),
+          '--json-output',
+          tempFile,
+          ...args.slice(separatorIndex),
+        ];
 
   await spawn('xcrun', [
     'devicectl',
     command,
-    ...args,
-    '--json-output',
-    tempFile,
+    ...argsWithJsonOutput,
   ]);
 
+  if (!fs.existsSync(tempFile)) {
+    throw new Error(`devicectl did not produce JSON output at ${tempFile}`);
+  }
+
   const output = fs.readFileSync(tempFile, 'utf8');
   fs.unlinkSync(tempFile);
 
@@ -106,7 +118,11 @@ export const getDeviceCtlLaunchArgs = (
     args.push('--environment-variables', JSON.stringify(environment));
   }
 
-  args.push(bundleId, ...(options?.arguments ?? []));
+  args.push(bundleId);
+
+  if (options?.arguments?.length) {
+    args.push('--', ...options.arguments);
+  }
 
   return args;
 };