Move screenshot to iOSBridge

Summary:
In order to support IOS cloud devices, we need to abstract
over the direct uses of idb/xcrun so we can switch them
out based on more than the device type.

Note that there's a bit of a type weirdness in there. I'll
clean this up with the next diff.

Reviewed By: mweststrate

Differential Revision: D30248036

fbshipit-source-id: ec8571429e04abe059850ef334a6645ae4a5e034

desktop/app/src/devices/IOSDevice.tsx

@@ -12,14 +12,10 @@ import child_process, {ChildProcess} from 'child_process';
 import BaseDevice from './BaseDevice';
 import JSONStream from 'JSONStream';
 import {Transform} from 'stream';
-import fs from 'fs-extra';
-import {v1 as uuid} from 'uuid';
-import path from 'path';
 import {exec} from 'promisify-child-process';
 import {default as promiseTimeout} from '../utils/promiseTimeout';
 import {IOSBridge} from '../utils/IOSBridge';
 import split2 from 'split2';
-import {getAppTempPath} from '../utils/pathUtils';
 
 type IOSLogLevel = 'Default' | 'Info' | 'Debug' | 'Error' | 'Fault';
 
@@ -67,19 +63,8 @@ export default class IOSDevice extends BaseDevice {
     if (!this.connected.get()) {
       return Buffer.from([]);
     }
-    const tmpImageName = uuid() + '.png';
-    const tmpDirectory = getAppTempPath();
-    const tmpFilePath = path.join(tmpDirectory, tmpImageName);
-    const command =
-      this.deviceType === 'emulator'
-        ? `xcrun simctl io ${this.serial} screenshot ${tmpFilePath}`
-        : `idb screenshot --udid ${this.serial} ${tmpFilePath}`;
-    return exec(command)
-      .then(() => fs.readFile(tmpFilePath))
-      .then(async (buffer) => {
-        await fs.unlink(tmpFilePath);
-        return buffer;
-      });
+    // HACK: Will restructure the types to allow for the ! to be removed.
+    return await this.iOSBridge.screenshot!(this.serial);
   }
 
   navigateToLocation(location: string) {

desktop/app/src/utils/IOSBridge.tsx

@@ -7,9 +7,13 @@
  * @format
  */
 
-import fs from 'fs';
+import fs from 'fs-extra';
 import child_process from 'child_process';
 import {DeviceType} from 'flipper-plugin-lib';
+import {v1 as uuid} from 'uuid';
+import path from 'path';
+import {exec} from 'promisify-child-process';
+import {getAppTempPath} from '../utils/pathUtils';
 
 export interface IOSBridge {
   idbAvailable: boolean;
@@ -17,6 +21,7 @@ export interface IOSBridge {
     udid: string,
     deviceType: DeviceType,
   ) => child_process.ChildProcessWithoutNullStreams;
+  screenshot?: (serial: string) => Promise<Buffer>;
 }
 
 async function isAvailable(idbPath: string): Promise<boolean> {
@@ -32,7 +37,8 @@ async function isAvailable(idbPath: string): Promise<boolean> {
 function getLogExtraArgs(deviceType: DeviceType) {
   if (deviceType === 'physical') {
     return [
-      // idb has a --json option, but that doesn't actually work!
+      // idb has a --json option, but that doesn't actually work for physical
+      // devices!
     ];
   } else {
     return [
@@ -77,6 +83,36 @@ export function xcrunStartLogListener(udid: string, deviceType: DeviceType) {
   );
 }
 
+function makeTempScreenshotFilePath() {
+  const imageName = uuid() + '.png';
+  const directory = getAppTempPath();
+  return path.join(directory, imageName);
+}
+
+function runScreenshotCommand(
+  command: string,
+  imagePath: string,
+): Promise<Buffer> {
+  return exec(command)
+    .then(() => fs.readFile(imagePath))
+    .then(async (buffer) => {
+      await fs.unlink(imagePath);
+      return buffer;
+    });
+}
+
+export async function xcrunScreenshot(serial: string): Promise<Buffer> {
+  const imagePath = makeTempScreenshotFilePath();
+  const command = `xcrun simctl io ${serial} screenshot ${imagePath}`;
+  return runScreenshotCommand(command, imagePath);
+}
+
+export async function idbScreenshot(serial: string): Promise<Buffer> {
+  const imagePath = makeTempScreenshotFilePath();
+  const command = `idb screenshot --udid ${serial} ${imagePath}`;
+  return runScreenshotCommand(command, imagePath);
+}
+
 export async function makeIOSBridge(
   idbPath: string,
   isXcodeDetected: boolean,
@@ -87,6 +123,7 @@ export async function makeIOSBridge(
     return {
       idbAvailable: true,
       startLogListener: idbStartLogListener.bind(null, idbPath),
+      screenshot: idbScreenshot,
     };
   }
 
@@ -95,6 +132,7 @@ export async function makeIOSBridge(
     return {
       idbAvailable: false,
       startLogListener: xcrunStartLogListener,
+      screenshot: xcrunScreenshot,
     };
   }
   // no idb, and not a simulator, we can't log this device

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

@@ -9,11 +9,15 @@
 
 import {makeIOSBridge} from '../IOSBridge';
 import childProcess from 'child_process';
+import * as promisifyChildProcess from 'promisify-child-process';
 import {mocked} from 'ts-jest/utils';
 
 jest.mock('child_process');
 const spawn = mocked(childProcess.spawn);
 
+jest.mock('promisify-child-process');
+const exec = mocked(promisifyChildProcess.exec);
+
 test('uses xcrun with no idb when xcode is detected', async () => {
   const ib = await makeIOSBridge('', true);
   expect(ib.startLogListener).toBeDefined();
@@ -92,3 +96,23 @@ test('uses no log listener when xcode is not detected', async () => {
   const ib = await makeIOSBridge('', false);
   expect(ib.startLogListener).toBeUndefined();
 });
+
+test('uses xcrun to take screenshots with no idb when xcode is detected', async () => {
+  const ib = await makeIOSBridge('', true);
+
+  ib.screenshot!('deadbeef');
+
+  expect(exec).toHaveBeenCalledWith(
+    'xcrun simctl io deadbeef screenshot /temp/00000000-0000-0000-0000-000000000000.png',
+  );
+});
+
+test('uses idb to take screenshots when available', async () => {
+  const ib = await makeIOSBridge('/usr/local/bin/idb', true, async (_) => true);
+
+  ib.screenshot!('deadbeef');
+
+  expect(exec).toHaveBeenCalledWith(
+    'idb screenshot --udid deadbeef /temp/00000000-0000-0000-0000-000000000000.png',
+  );
+});