feat (doctor): add packager healthcheck to report if packager is running correctly

packages/cli-doctor/package.json

@@ -12,6 +12,7 @@
     "@react-native-community/cli-platform-android": "12.0.0-alpha.3",
     "@react-native-community/cli-platform-ios": "12.0.0-alpha.3",
     "@react-native-community/cli-tools": "12.0.0-alpha.3",
+    "@react-native-community/cli-plugin-metro": "12.0.0-alpha.3",
     "chalk": "^4.1.2",
     "command-exists": "^1.2.8",
     "envinfo": "^7.7.2",

packages/cli-doctor/src/tools/healthchecks/index.ts

@@ -14,6 +14,7 @@ import iosDeploy from './iosDeploy';
 import {Healthchecks, HealthCheckCategory} from '../../types';
 import loadConfig from '@react-native-community/cli-config';
 import xcodeEnv from './xcodeEnv';
+import packager from './packager';
 
 export const HEALTHCHECK_TYPES = {
   ERROR: 'ERROR',
@@ -41,6 +42,7 @@ export const getHealthchecks = ({contributor}: Options): Healthchecks => {
         nodeJS,
         yarn,
         npm,
+        packager,
         ...(process.platform === 'darwin' ? [watchman] : []),
       ],
     },

packages/cli-doctor/src/tools/healthchecks/packager.ts

@@ -0,0 +1,51 @@
+import {
+  getDefaultUserTerminal,
+  isPackagerRunning,
+} from '@react-native-community/cli-tools';
+import {HealthCheckInterface} from '../../types';
+import {logManualInstallation} from './common';
+import {startServerInNewWindow} from '@react-native-community/cli-plugin-metro';
+
+export default {
+  label: 'Metro',
+  isRequired: false,
+  description: 'Required for bundling the JavaScript code',
+  getDiagnostics: async () => {
+    const status = await isPackagerRunning();
+    const needsToBeFixed = status === 'not_running';
+    if (needsToBeFixed) {
+      return {
+        description: 'Metro Bundler is not running',
+        needsToBeFixed,
+      };
+    }
+    return {
+      needsToBeFixed,
+    };
+  },
+  runAutomaticFix: async ({loader, config}) => {
+    loader.fail();
+    try {
+      const terminal = getDefaultUserTerminal();
+      const port = Number(process.env.RCT_METRO_PORT) || 8081;
+      if (terminal && config) {
+        startServerInNewWindow(
+          port,
+          terminal,
+          config.root,
+          config.reactNativePath,
+        );
+        return loader.succeed();
+      }
+      return logManualInstallation({
+        message:
+          'Could not start the bundler. Please run "react-native start" command manually.',
+      });
+    } catch (error) {
+      return logManualInstallation({
+        message:
+          'Could not start the bundler. Please run "react-native start" command manually.',
+      });
+    }
+  },
+} as HealthCheckInterface;

packages/cli-doctor/tsconfig.json

@@ -9,6 +9,7 @@
     {"path": "../cli-types"},
     {"path": "../cli-config"},
     {"path": "../cli-platform-android"},
-    {"path": "../cli-platform-ios"}
+    {"path": "../cli-platform-ios"},
+    {"path": "../cli-plugin-metro"},
   ]
 }

packages/cli-platform-android/src/commands/buildAndroid/index.ts

@@ -10,7 +10,7 @@ import execa from 'execa';
 import {getAndroidProject} from '../../config/getAndroidProject';
 import adb from '../runAndroid/adb';
 import getAdbPath from '../runAndroid/getAdbPath';
-import {startServerInNewWindow} from './startServerInNewWindow';
+import {startServerInNewWindow} from '@react-native-community/cli-plugin-metro';
 import {getTaskNames} from '../runAndroid/getTaskNames';
 import {promptForTaskSelection} from '../runAndroid/listAndroidTasks';
 

packages/cli-platform-android/tsconfig.json

@@ -4,5 +4,9 @@
     "rootDir": "src",
     "outDir": "build"
   },
-  "references": [{"path": "../cli-tools"}, {"path": "../cli-types"}]
+  "references": [
+    {"path": "../cli-tools"},
+    {"path": "../cli-types"},
+    {"path": "../cli-plugin-metro"}
+  ]
 }

packages/cli-plugin-metro/src/commands/index.ts

@@ -4,3 +4,4 @@ import startCommand from './start';
 export default [bundleCommand, ramBundleCommand, startCommand];
 export {buildBundleWithConfig} from './bundle';
 export type {CommandLineArgs} from './bundle';
+export {startServerInNewWindow} from './start';

packages/cli-plugin-metro/src/commands/start/index.ts

@@ -90,3 +90,5 @@ export default {
     },
   ],
 };
+
+export {startServerInNewWindow} from './startServerInNewWindow';

packages/cli-plugin-metro/src/index.ts

@@ -8,4 +8,5 @@ export {
   default as commands,
   buildBundleWithConfig,
   CommandLineArgs,
+  startServerInNewWindow,
 } from './commands';