Cleanup support DDC debugging tools.

lib/src/dartdevc/dartdevc.dart

 // Copyright (c) 2017, 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.
 
 import 'dart:async';
 import 'dart:io';
 import 'dart:convert' show JsonEncoder;
 
 import 'package:analyzer/analyzer.dart';
 import 'package:barback/barback.dart';
 import 'package:bazel_worker/bazel_worker.dart';
 import 'package:cli_util/cli_util.dart' as cli_util;
 import 'package:path/path.dart' as p;
 
 import '../dart.dart';
 import '../io.dart';
 import 'module.dart';
 import 'module_reader.dart';
 import 'scratch_space.dart';
 import 'summaries.dart';
 import 'workers.dart';
 
-// JavaScript snippet to determine the directory a script was run from.
+/// JavaScript snippet to determine the directory a script was run from.
 final _currentDirectoryScript = r'''
 var _currentDirectory = (function () {
   var _url;
   var lines = new Error().stack.split('\n');
   function lookupUrl() {
     if (lines.length > 2) {
       var match = lines[1].match(/^\s+at (.+):\d+:\d+$/);
       // Chrome.
       if (match) return match[1];
       // Chrome nested eval case.
@@ skipping 51 matching lines @@
     ModuleReader moduleReader,
     Future<Asset> getAsset(AssetId id)) {
   var bootstrapId = dartEntrypointId.addExtension('.bootstrap.js');
   var jsEntrypointId = dartEntrypointId.addExtension('.js');
   var jsMapEntrypointId = jsEntrypointId.addExtension('.map');
 
   var outputCompleters = <AssetId, Completer<Asset>>{
     bootstrapId: new Completer(),
     jsEntrypointId: new Completer(),
   };
-  var debugMode = mode == BarbackMode.DEBUG;
+  var isDebug = mode == BarbackMode.DEBUG;
 
-  if (debugMode) {
+  if (isDebug) {
     outputCompleters[jsMapEntrypointId] = new Completer<Asset>();
   }
 
   return _ensureComplete(outputCompleters, () async {
     var module = await moduleReader.moduleFor(dartEntrypointId);
     if (module == null) return;
 
     // The path to the entrypoint JS module as it should appear in the call to
     // `require` in the bootstrap file.
     var moduleDir = topLevelDir(dartEntrypointId.path);
@@ skipping 12 matching lines @@
     // internally, but instead specify our own.
     var appModuleScope = p.url
         .split(p.url.withoutExtension(
             p.url.relative(dartEntrypointId.path, from: moduleDir)))
         .join("__")
         .replaceAll('.', '\$46');
 
     // Map from module name to module path.
     // Modules outside of the `packages` directory have different module path
     // and module names.
-    var modulePaths = new Map<String, String>();
-    modulePaths[appModulePath] = appModulePath;
-    modulePaths['dart_sdk'] = 'dart_sdk';
-
+    var modulePaths = {
+      appModulePath: appModulePath,
+      'dart_sdk': 'dart_sdk'
+    };
     var transitiveDeps = await moduleReader.readTransitiveDeps(module);
     for (var dep in transitiveDeps) {
       if (dep.dir != 'lib') {
         var relativePath = p.url.relative(p.url.join(moduleDir, dep.name),
             from: p.url.dirname(bootstrapId.path));
         var jsModuleName = '${dep.dir}/${dep.name}';
 
         modulePaths[jsModuleName] = relativePath;
       } else {
         var jsModuleName = 'packages/${dep.package}/${dep.name}';
         var actualModulePath = p.url.relative(
             p.url.join(moduleDir, jsModuleName),
             from: p.url.dirname(bootstrapId.path));
         modulePaths[jsModuleName] = actualModulePath;
       }
     }
     var bootstrapContent = new StringBuffer('(function() {\n');
-    if (debugMode) {
+    if (isDebug) {
       bootstrapContent.write('''
 $_currentDirectoryScript
 let modulePaths = ${const JsonEncoder.withIndent(" ").convert(modulePaths)};
 
 if(!window.\$dartLoader) {
    window.\$dartLoader = {
      moduleIdToUrl: new Map(),
      urlToModuleId: new Map(),
      rootDirectories: new Set(),
    };
 }
 
 let customModulePaths = {};
 window.\$dartLoader.rootDirectories.add(_currentDirectory);
 for (let moduleName of Object.getOwnPropertyNames(modulePaths)) {
   let modulePath = modulePaths[moduleName];
   if (modulePath != moduleName) {
     customModulePaths[moduleName] = modulePath;
   }
   var src = _currentDirectory + modulePath + '.js';
   if (window.\$dartLoader.moduleIdToUrl.has(moduleName)) {
     continue;
   }
   \$dartLoader.moduleIdToUrl.set(moduleName, src);
   \$dartLoader.urlToModuleId.set(src, moduleName);
 }
 ''');
     } else {
-      var customModulePaths = new Map<String, String>();
+      var customModulePaths = <String, String>{};
       modulePaths.forEach((name, path) {
         if (name != path) customModulePaths[name] = path;
       });
       var json = const JsonEncoder.withIndent(" ").convert(customModulePaths);
       bootstrapContent.write('let customModulePaths = ${json};\n');
     }
 
     bootstrapContent.write('''
 require.config({
     waitSeconds: 30,
     paths: customModulePaths
 });
 
 require(["$appModulePath", "dart_sdk"], function(app, dart_sdk) {
   dart_sdk._isolate_helper.startRootIsolate(() => {}, []);
 ''');
 
-    if (debugMode) {
+    if (isDebug) {
       bootstrapContent.write('''
   dart_sdk._debugger.registerDevtoolsFormatter();
 
   if (window.\$dartStackTraceUtility && !window.\$dartStackTraceUtility.ready) {
     window.\$dartStackTraceUtility.ready = true;
     let dart = dart_sdk.dart;
     window.\$dartStackTraceUtility.setSourceMapProvider(
       function(url) {
         var module = window.\$dartLoader.urlToModuleId.get(url);
         if (!module) return null;
@@ skipping 10 matching lines @@
 })();
 ''');
     outputCompleters[bootstrapId].complete(
         new Asset.fromString(bootstrapId, bootstrapContent.toString()));
 
     var bootstrapModuleName = p.withoutExtension(
         p.relative(bootstrapId.path, from: p.dirname(dartEntrypointId.path)));
     var entrypointJsContent = new StringBuffer('''
 var el;
 ''');
-    if (debugMode) {
+    if (isDebug) {
       entrypointJsContent.write('''
 el = document.createElement("script");
 el.defer = true;
 el.async = false;
 el.src = "dart_stack_trace_mapper.js";
 document.head.appendChild(el);
 ''');
     }
 
     entrypointJsContent.write('''
 el = document.createElement("script");
 el.defer = true;
 el.async = false;
 el.src = "require.js";
 el.setAttribute("data-main", "$bootstrapModuleName");
 document.head.appendChild(el);
 ''');
     outputCompleters[jsEntrypointId].complete(
         new Asset.fromString(jsEntrypointId, entrypointJsContent.toString()));
 
-    if (debugMode) {
+    if (isDebug) {
       outputCompleters[jsMapEntrypointId].complete(new Asset.fromString(
           jsMapEntrypointId,
           '{"version":3,"sourceRoot":"","sources":[],"names":[],"mappings":"",'
           '"file":""}'));
     }
   });
 }
 
 /// Compiles [module] using the `dartdevc` binary from the SDK to a relative
 /// path under the package that looks like `$outputDir/${module.id.name}.js`.
 ///
 /// Synchronously returns a `Map<AssetId, Future<Asset>>` so that you can know
 /// immediately what assets will be output.
 Map<AssetId, Future<Asset>> createDartdevcModule(
     AssetId id,
     ModuleReader moduleReader,
     ScratchSpace scratchSpace,
     Map<String, String> environmentConstants,
     BarbackMode mode,
     logError(String message)) {
   assert(id.extension == '.js');
   var outputCompleters = <AssetId, Completer<Asset>>{
     id: new Completer(),
   };
-  var debugMode = mode == BarbackMode.DEBUG;
-  if (debugMode) {
+  var isDebug = mode == BarbackMode.DEBUG;
+  if (isDebug) {
     outputCompleters[id.addExtension('.map')] = new Completer();
   }
 
   return _ensureComplete(outputCompleters, () async {
     var module = await moduleReader.moduleFor(id);
     if (module == null) return;
     var transitiveModuleDeps = await moduleReader.readTransitiveDeps(module);
     var linkedSummaryIds =
         transitiveModuleDeps.map((depId) => depId.linkedSummaryId).toSet();
     var allAssetIds = new Set<AssetId>()
@@ skipping 11 matching lines @@
       '--modules=amd',
       '--dart-sdk=${sdkDir.path}',
       '--module-root=${scratchSpace.tempDir.path}',
       '--library-root=${p.dirname(jsOutputFile.path)}',
       '--summary-extension=${linkedSummaryExtension.substring(1)}',
       '--no-summarize',
       '-o',
       jsOutputFile.path,
     ]);
 
-    if (debugMode) {
+    if (isDebug) {
       request.arguments.addAll([
         '--source-map',
         '--source-map-comment',
         '--inline-source-map',
       ]);
     } else {
       request.arguments.add('--no-source-map');
     }
 
     // Add environment constants.
@@ skipping 29 matching lines @@
 
     // TODO(jakemac53): Fix the ddc worker mode so it always sends back a bad
     // status code if something failed. Today we just make sure there is an output
     // JS file to verify it was successful.
     if (response.exitCode != EXIT_CODE_OK || !jsOutputFile.existsSync()) {
       logError('Error compiling dartdevc module: ${module.id}.\n'
           '${response.output}');
     } else {
       outputCompleters[module.id.jsId].complete(
           new Asset.fromBytes(module.id.jsId, jsOutputFile.readAsBytesSync()));
-      if (debugMode) {
+      if (isDebug) {
         var sourceMapFile = scratchSpace.fileFor(module.id.jsSourceMapId);
         outputCompleters[module.id.jsSourceMapId].complete(new Asset.fromBytes(
             module.id.jsSourceMapId, sourceMapFile.readAsBytesSync()));
       }
     }
   });
 }
 
 /// Copies the `dart_sdk.js` and `require.js` AMD files from the SDK into
 /// [outputDir].
@@ skipping 44 matching lines @@
     } finally {
       for (var id in completers.keys) {
         if (!completers[id].isCompleted) {
           completers[id].completeError(new AssetNotFoundException(id));
         }
       }
     }
   }();
   return futures;
 }