Start bridge abstraction

Summary: This is just an early start of centralising some ad-hoc logic we've got all over the place right now. Memoised do-we-have-idb calls with concatenated shell invocations. This gives us the opportunity to do a bit of testing, too.

Reviewed By: mweststrate

Differential Revision: D26694863

fbshipit-source-id: cd2b9883f90397802bbaae6030f7cb3881c565c2

desktop/app/src/utils/__tests__/IOSBridge.node.tsx

@@ -0,0 +1,60 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @format
+ */
+
+import {makeIOSBridge} from '../IOSBridge';
+import childProcess from 'child_process';
+import {mocked} from 'ts-jest/utils';
+
+jest.mock('child_process');
+const spawn = mocked(childProcess.spawn);
+
+test('uses xcrun with no idb', async () => {
+  const ib = await makeIOSBridge('');
+  ib.startLogListener('deadbeef');
+
+  expect(spawn).toHaveBeenCalledWith(
+    'xcrun',
+    [
+      'simctl',
+      'spawn',
+      'deadbeef',
+      'log',
+      'stream',
+      '--style',
+      'json',
+      '--predicate',
+      'senderImagePath contains "Containers"',
+      '--debug',
+      '--info',
+    ],
+    {},
+  );
+});
+
+test('uses idb when present', async () => {
+  const ib = await makeIOSBridge('/usr/local/bin/idb');
+  ib.startLogListener('deadbeef');
+
+  expect(spawn).toHaveBeenCalledWith(
+    '/usr/local/bin/idb',
+    [
+      'log',
+      '--udid',
+      'deadbeef',
+      '--',
+      '--style',
+      'json',
+      '--predicate',
+      'senderImagePath contains "Containers"',
+      '--debug',
+      '--info',
+    ],
+    {},
+  );
+});