update_homebrew: more fixes

tools/apps/update_homebrew/bin/update_homebrew.dart

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library update_homebrew;
 
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
 
 import 'package:args/args.dart';
 import 'package:googleapis/common/common.dart' show DownloadOptions, Media;
 import 'package:googleapis/storage/v1.dart' as storage;
 import 'package:http/http.dart' as http;
 import 'package:stack_trace/stack_trace.dart';
 
 String repository; // The path to the temporary git checkout of dart-homebrew.
 Map gitEnvironment; // Pass a wrapper script for SSH to git in the environment.
 
 const GITHUB_REPO = 'dart-lang/homebrew-dart';
 
 const CHANNELS = const ['dev', 'stable'];
 
-const SDK_FILES = const [
-  'sdk/dartsdk-macos-x64-release.zip',
-  'sdk/dartsdk-macos-ia32-release.zip'
-];
+const FILES = const [x64File, ia32File, dartiumFile, contentShellFile];
 
-const DARTIUM_FILES = const [
-  'dartium/dartium-macos-ia32-release.zip',
-  'dartium/content_shell-macos-ia32-release.zip'
-];
-
-final FILES = []..addAll(SDK_FILES)..addAll(DARTIUM_FILES);
+const urlBase = 'https://storage.googleapis.com/dart-archive/channels';
+const x64File = 'sdk/dartsdk-macos-x64-release.zip';
+const ia32File = 'sdk/dartsdk-macos-ia32-release.zip';
+const dartiumFile = 'dartium/dartium-macos-ia32-release.zip';
+const contentShellFile = 'dartium/content_shell-macos-ia32-release.zip';
 
 Future<String> getHash256(
     String channel, String revision, String download) async {
   var client = new http.Client();
   try {
     var api = new storage.StorageApi(client);
     var media = await api.objects.get('dart-archive',
         'channels/$channel/release/$revision/$download.sha256sum',
         downloadOptions: DownloadOptions.FullMedia);
 
@@ skipping 13 matching lines @@
         'dart-archive', 'channels/$channel/release/$revision/VERSION',
         downloadOptions: DownloadOptions.FullMedia);
 
     var versionObject = await JSON.fuse(ASCII).decoder.bind(media.stream).first;
     return versionObject['version'];
   } finally {
     client.close();
   }
 }
 
-Future setCurrentRevisions(Map revisions) async {
+Future<Map> getCurrentRevisions() async {
+  var revisions = <String, String>{};
   var lines = await (new File('$repository/dart.rb')).readAsLines();
 
   for (var channel in CHANNELS) {
     /// This RegExp between release/ and /sdk matches
     /// * 1 digit followed by
     /// * Any number of letters, numbers, dashes and dots
     /// This covers both numeric- and version-formatted revisions
     ///
     /// Note: all of the regexp escape slashes `\` are double-escaped within the
     /// Dart string
     final regExp =
         new RegExp('channels/$channel/release/(\\d[\\w\\d\\-\\.]*)/sdk');
 
     revisions[channel] =
         regExp.firstMatch(lines.firstWhere(regExp.hasMatch)).group(1);
   }
+  return revisions;
 }
 
-Future setHashes(Map revisions, Map hashes) {
-  List waitOn = [];
+Future<Map> getHashes(Map revisions) async {
+  var hashes = <String, Map>{};
   for (var channel in CHANNELS) {
     hashes[channel] = {};
     for (var file in FILES) {
-      waitOn.add(getHash256(channel, revisions[channel], file).then((hash) {
-        hashes[channel][file] = hash;
-      }));
+      var hash = await getHash256(channel, revisions[channel], file);
+      hashes[channel][file] = hash;
     }
   }
-  return Future.wait(waitOn);
+  return hashes;
 }
 
 Future writeHomebrewInfo(String channel, String revision) async {
-  var revisions = {};
-  var hashes = {};
-
-  await setCurrentRevisions(revisions);
+  var revisions = await getCurrentRevisions();
 
   if (revisions[channel] == revision) {
     print("Channel $channel is already at revision $revision in homebrew.");
     exit(0);
   }
   revisions[channel] = revision;
-  await setHashes(revisions, hashes);
+  var hashes = await getHashes(revisions);
   var devVersion = await getVersion('dev', revisions['dev']);
 
   var stableVersion = await getVersion('stable', revisions['stable']);
 
-  await (new File('$repository/dartium.rb').openWrite()
-    ..write(DartiumFile(revisions, hashes, devVersion, stableVersion))).close();
-  await (new File('$repository/dart.rb').openWrite()
-    ..write(DartFile(revisions, hashes, devVersion, stableVersion))).close();
+  await new File('$repository/dartium.rb').writeAsString(
+      createDartiumFormula(revisions, hashes, devVersion, stableVersion),
+      flush: true);
+  await new File('$repository/dart.rb').writeAsString(
+      createDartFormula(revisions, hashes, devVersion, stableVersion),
+      flush: true);
 }
 
-String DartiumFile(
-    Map revisions, Map hashes, String devVersion, String stableVersion) {
-  final urlBase = 'https://storage.googleapis.com/dart-archive/channels';
-  final dartiumFile = 'dartium/dartium-macos-ia32-release.zip';
-  final contentShellFile = 'dartium/content_shell-macos-ia32-release.zip';
-
-  return '''
+String createDartiumFormula(
+    Map revisions, Map hashes, String devVersion, String stableVersion) => '''
 require 'formula'
 
 class Dartium < Formula
   homepage "https://www.dartlang.org"
 
   version '$stableVersion'
   url '$urlBase/stable/release/${revisions['stable']}/$dartiumFile'
   sha256 '${hashes['stable'][dartiumFile]}'
 
   devel do
@@ skipping 35 matching lines @@
      To use with IntelliJ, set the Dartium execute home to:
         #{prefix}/Chromium.app
     EOS
   end
 
   test do
     system "#{bin}/dartium"
   end
 end
 ''';
-}
 
-String DartFile(
-    Map revisions, Map hashes, String devVersion, String stableVersion) {
-  final urlBase = 'https://storage.googleapis.com/dart-archive/channels';
-  final x64File = 'sdk/dartsdk-macos-x64-release.zip';
-  final ia32File = 'sdk/dartsdk-macos-ia32-release.zip';
-
-  return '''
+String createDartFormula(
+    Map revisions, Map hashes, String devVersion, String stableVersion) => '''
 require 'formula'
 
 class Dart < Formula
   homepage 'https://www.dartlang.org/'
 
   version '$stableVersion'
   if MacOS.prefer_64_bit?
     url '$urlBase/stable/release/${revisions['stable']}/$x64File'
     sha256 '${hashes['stable'][x64File]}'
   else
@@ skipping 28 matching lines @@
     (testpath/'sample.dart').write <<-EOS.undent
       void main() {
         print(r"test message");
       }
     EOS
 
     assert_equal "test message\\n", shell_output("#{bin}/dart sample.dart")
   end
 end
 ''';
-}
 
 Future runGit(List<String> args) async {
   print("git ${args.join(' ')}");
 
   var result = await Process.run('git', args,
       workingDirectory: repository, environment: gitEnvironment);
 
   print(result.stdout);
   print(result.stderr);
 }
@@ skipping 32 matching lines @@
 
       await runGit(['push']);
     } finally {
       await tempDir.delete(recursive: true);
     }
   }, onError: (error, chain) {
     print(error);
     print(chain.terse);
   });
 }