Fixes for the Metro cli

Reviewed By: BYK

Differential Revision: D6348698

fbshipit-source-id: 3a00d9af7e03c5d636e2a51ce95842ca7d45b6e1

packages/metro-bundler/package.json

@@ -30,6 +30,7 @@
     "debug": "^2.2.0",
     "denodeify": "^1.2.1",
     "fbjs": "^0.8.14",
+    "fs-extra": "^1.0.0",
     "graceful-fs": "^4.1.3",
     "image-size": "^0.6.0",
     "jest-docblock": "21.3.0-beta.8",

packages/metro-bundler/src/cli-utils.js

@@ -19,9 +19,9 @@ import type {ConfigT} from './Config';
 
 const METRO_CONFIG_FILENAME = 'metro.config.js';
 
-exports.findMetroConfig = async (
+exports.findMetroConfig = async function(
   filename: ?string,
-): Promise<$Shape<ConfigT>> => {
+): Promise<$Shape<ConfigT>> {
   if (filename) {
     // $FlowFixMe: We want this require to be dynamic
     return require(path.resolve(process.cwd(), filename));
@@ -44,3 +44,14 @@ exports.findMetroConfig = async (
     return {};
   }
 };
+
+// eslint-disable-next-line no-unclear-flowtypes
+exports.makeAsyncCommand = (command: (argv: any) => Promise<*>) => (
+  // eslint-disable-next-line no-unclear-flowtypes
+  argv: any,
+) => {
+  Promise.resolve(command(argv)).catch(error => {
+    console.error(error.stack);
+    process.exitCode = 1;
+  });
+};

packages/metro-bundler/src/commands/build.js

@@ -13,10 +13,11 @@
 'use strict';
 
 const MetroApi = require('..');
-const findMetroConfig = require('../cli-utils').findMetroConfig;
 
 const os = require('os');
 
+const {findMetroConfig, makeAsyncCommand} = require('../cli-utils');
+
 import typeof Yargs from 'yargs';
 
 exports.command = 'build <entry>';
@@ -49,8 +50,8 @@ exports.builder = (yargs: Yargs) => {
   yargs.option('config', {alias: 'c', type: 'string'});
 };
 
-exports.handler = async (argv: any) => {
+// eslint-disable-next-line no-unclear-flowtypes
+exports.handler = makeAsyncCommand(async (argv: any) => {
   argv.config = await findMetroConfig(argv.config);
-
   await MetroApi.runBuild(argv);
-};
+});

packages/metro-bundler/src/commands/serve.js

@@ -13,10 +13,11 @@
 'use strict';
 
 const MetroApi = require('..');
-const findMetroConfig = require('../cli-utils').findMetroConfig;
 
 const os = require('os');
 
+const {findMetroConfig, makeAsyncCommand} = require('../cli-utils');
+
 import typeof Yargs from 'yargs';
 
 exports.command = 'serve';
@@ -46,7 +47,8 @@ exports.builder = (yargs: Yargs) => {
   yargs.option('config', {alias: 'c', type: 'string'});
 };
 
-exports.handler = async (argv: any) => {
+// eslint-disable-next-line no-unclear-flowtypes
+exports.handler = makeAsyncCommand(async (argv: any) => {
   argv.config = await findMetroConfig(argv.config);
 
   await MetroApi.runServer({
@@ -58,4 +60,4 @@ exports.handler = async (argv: any) => {
       );
     },
   });
-};
+});

packages/metro-bundler/src/index.js

@@ -22,8 +22,8 @@ const TransformCaching = require('./lib/TransformCaching');
 
 const connect = require('connect');
 
+const {realpath} = require('fs');
 const {readFile} = require('fs-extra');
-const {resolve} = require('path');
 
 const defaultAssetExts = require('./defaults').assetExts;
 const defaultSourceExts = require('./defaults').sourceExts;
@@ -56,7 +56,22 @@ type PrivateMetroOptions = {|
   watch?: boolean,
 |};
 
-function runMetro({
+// We'll be able to remove this to use the one provided by modern versions of
+// fs-extra once https://github.com/jprichardson/node-fs-extra/pull/520 will
+// have been merged (until then, they'll break on devservers/Sandcastle)
+async function asyncRealpath(path): Promise<string> {
+  return new Promise((resolve, reject) => {
+    realpath(path, (error, result) => {
+      if (error) {
+        reject(error);
+      } else {
+        resolve(result);
+      }
+    });
+  });
+}
+
+async function runMetro({
   config,
   maxWorkers = 1,
   projectRoots,
@@ -105,9 +120,12 @@ function runMetro({
     watch,
     workerPath:
       normalizedConfig.getWorkerPath && normalizedConfig.getWorkerPath(),
-    projectRoots: normalizedConfig
+    projectRoots: await Promise.all(
+      normalizedConfig
         .getProjectRoots()
-      .concat([...projectRoots.map(path => resolve(path))]),
+        .concat(projectRoots)
+        .map(path => asyncRealpath(path)),
+    ),
   };
 
   return new MetroServer(serverOptions);
@@ -117,8 +135,10 @@ type CreateConnectMiddlewareOptions = {|
   ...PublicMetroOptions,
 |};
 
-exports.createConnectMiddleware = (options: CreateConnectMiddlewareOptions) => {
+exports.createConnectMiddleware = async function(
-  const metroServer = runMetro({
+  options: CreateConnectMiddlewareOptions,
+) {
+  const metroServer = await runMetro({
     config: options.config,
     maxWorkers: options.maxWorkers,
     projectRoots: options.projectRoots,

packages/metro-bundler/src/shared/output/meta.js

@@ -31,7 +31,8 @@ module.exports = function(
   const buffer: Buffer = asBuffer(code, encoding);
   const hash = crypto.createHash('sha1');
   hash.update(buffer);
-  const digest = hash.digest();
+  // $FlowFixMe: Flow doesn't know that 'buffer' is a valid value
+  const digest = hash.digest('buffer');
   const signature = Buffer.alloc
     ? Buffer.alloc(digest.length + 1)
     : new Buffer(digest.length + 1);