Allow specifying an appIdSuffix to run-android

Summary:
Motivation

Currently react-native run-android instals and starts your app, but if you have more than one variant, it doesn't know which one to start.  This allows developers to pass in the suffix specified in build.gradle, so that the correct app is started.

Test Plan

verify that `react-native run-android` runs properly
verify that `react-native run-android --appIdSuffix validSuffix` runs properly
Closes https://github.com/facebook/react-native/pull/13169

Differential Revision: D4823391

Pulled By: ericvicenti

fbshipit-source-id: 31ed35fd79403804b4781e81eb49f1c4627d7f8e

local-cli/runAndroid/runAndroid.js

@@ -90,24 +90,26 @@ function buildAndRun(args) {
       'utf8'
     ).match(/package="(.+?)"/)[1];
 
+  const packageNameWithSuffix = args.appIdSuffix ? packageName + '.' + args.appIdSuffix : packageName;
+
   const adbPath = getAdbPath();
   if (args.deviceId) {
     if (isString(args.deviceId)) {
-        runOnSpecificDevice(args, cmd, packageName, adbPath);
+        runOnSpecificDevice(args, cmd, packageNameWithSuffix, packageName, adbPath);
     } else {
       console.log(chalk.red('Argument missing for parameter --deviceId'));
     }
   } else {
-    runOnAllDevices(args, cmd, packageName, adbPath);
+    runOnAllDevices(args, cmd, packageNameWithSuffix, packageName, adbPath);
   }
 }
 
-function runOnSpecificDevice(args, gradlew, packageName, adbPath) {
+function runOnSpecificDevice(args, gradlew, packageNameWithSuffix, packageName, adbPath) {
   let devices = adb.getDevices();
   if (devices && devices.length > 0) {
     if (devices.indexOf(args.deviceId) !== -1) {
       buildApk(gradlew);
-      installAndLaunchOnDevice(args, args.deviceId, packageName, adbPath);
+      installAndLaunchOnDevice(args, args.deviceId, packageNameWithSuffix, packageName, adbPath);
     } else {
       console.log('Could not find device with the id: "' + args.deviceId + '".');
       console.log('Choose one of the following:');
@@ -150,9 +152,9 @@ function tryInstallAppOnDevice(args, device) {
   }
 }
 
-function tryLaunchAppOnDevice(device, packageName, adbPath, mainActivity) {
+function tryLaunchAppOnDevice(device, packageNameWithSuffix, packageName, adbPath, mainActivity) {
   try {
-    const adbArgs = ['-s', device, 'shell', 'am', 'start', '-n', packageName + '/.' + mainActivity];
+    const adbArgs = ['-s', device, 'shell', 'am', 'start', '-n', packageNameWithSuffix + '/' + packageName + '.' + mainActivity];
     console.log(chalk.bold(
       `Starting the app on ${device} (${adbPath} ${adbArgs.join(' ')})...`
     ));
@@ -164,13 +166,13 @@ function tryLaunchAppOnDevice(device, packageName, adbPath, mainActivity) {
   }
 }
 
-function installAndLaunchOnDevice(args, selectedDevice, packageName, adbPath) {
+function installAndLaunchOnDevice(args, selectedDevice, packageNameWithSuffix, packageName, adbPath) {
   tryRunAdbReverse(selectedDevice);
   tryInstallAppOnDevice(args, selectedDevice);
-  tryLaunchAppOnDevice(selectedDevice, packageName, adbPath, args.mainActivity);
+  tryLaunchAppOnDevice(selectedDevice, packageNameWithSuffix, packageName, adbPath, args.mainActivity);
 }
 
-function runOnAllDevices(args, cmd, packageName, adbPath){
+function runOnAllDevices(args, cmd, packageNameWithSuffix, packageName, adbPath){
   try {
     const gradleArgs = [];
     if (args.variant) {
@@ -215,14 +217,14 @@ function runOnAllDevices(args, cmd, packageName, adbPath){
     if (devices && devices.length > 0) {
       devices.forEach((device) => {
         tryRunAdbReverse(device);
-        tryLaunchAppOnDevice(device, packageName, adbPath, args.mainActivity);
+        tryLaunchAppOnDevice(device, packageNameWithSuffix, packageName, adbPath, args.mainActivity);
       });
     } else {
       try {
         // If we cannot execute based on adb devices output, fall back to
         // shell am start
         const fallbackAdbArgs = [
-          'shell', 'am', 'start', '-n', packageName + '/.MainActivity'
+          'shell', 'am', 'start', '-n', packageNameWithSuffix + '/' + packageName + '.MainActivity'
         ];
         console.log(chalk.bold(
           `Starting the app (${adbPath} ${fallbackAdbArgs.join(' ')}...`
@@ -286,6 +288,10 @@ module.exports = {
     description: '--flavor has been deprecated. Use --variant instead',
   }, {
     command: '--variant [string]',
+  }, {
+    command: '--appIdSuffix [string]',
+    description: 'Specify an applicationIdSuffix to launch after build.',
+    default: '',
   }, {
     command: '--main-activity [string]',
     description: 'Name of the activity to start',