From 7040d487d8057bd2aabba72f27ed5f2498caa7e8 Mon Sep 17 00:00:00 2001
From: Michel Weststrate <mweststrate@fb.com>
Date: Wed, 6 Nov 2019 06:16:08 -0800
Subject: [PATCH] don't keep querying iOS simulators if XCode was not installed
 properly

Summary: Currently the app keeps to find iOS devices if when the tooling isn't properly set up, causing an error to appear every three secs. This change makes sure that happens only once. It also takes care of some run-away promises

Reviewed By: jknoxville

Differential Revision: D18346619

fbshipit-source-id: 12b581bee0d522b37b9e0c5d5b8dad0e4d2058d9
---
 src/dispatcher/iOSDevice.tsx | 33 +++++++++++++++++++++++++++++++--
 1 file changed, 31 insertions(+), 2 deletions(-)

diff --git a/src/dispatcher/iOSDevice.tsx b/src/dispatcher/iOSDevice.tsx
index 57a3f2750..e36a073c6 100644
--- a/src/dispatcher/iOSDevice.tsx
+++ b/src/dispatcher/iOSDevice.tsx
@@ -66,8 +66,11 @@ if (typeof window !== 'undefined') {
   });
 }
 
-function queryDevices(store: Store, logger: Logger): Promise<void> {
-  checkXcodeVersionMismatch();
+async function queryDevices(store: Store, logger: Logger): Promise<void> {
+  if (!(await checkIfDevicesCanBeQueryied(store))) {
+    return;
+  }
+  await checkXcodeVersionMismatch();
   const {connections} = store.getState();
   const currentDeviceIDs: Set<string> = new Set(
     connections.devices
@@ -192,6 +195,32 @@ async function checkXcodeVersionMismatch() {
   }
 }
 
+let canQueryDevices: boolean | undefined = undefined;
+
+async function checkIfDevicesCanBeQueryied(store: Store): Promise<boolean> {
+  if (canQueryDevices !== undefined) {
+    return canQueryDevices;
+  }
+  try {
+    const exec = promisify(child_process.exec);
+    // make sure we can use instruments (it will throw otherwise)
+    await exec('instruments -s devices');
+    return (canQueryDevices = true);
+  } catch (e) {
+    store.dispatch({
+      type: 'SERVER_ERROR',
+      payload: {
+        message:
+          'It looks like XCode was not installed properly. Further actions are required if you want to use an iOS emulator.',
+        details:
+          "You might want to run 'sudo xcode-select -s /Applications/Xcode.app/Contents/Developer'",
+        error: e,
+      },
+    });
+    return (canQueryDevices = false);
+  }
+}
+
 async function isXcodeDetected(): Promise<boolean> {
   return promisify(child_process.exec)('xcode-select -p')
     .then(_ => true)