refactor(transformer): precompile stylesheets

Part of #3605

modules_dart/transform/lib/src/transform/stylesheet_compiler/processor.dart

@@ -0,0 +1,37 @@
+library angular2.transform.stylesheet_compiler.processor;
+
+import 'dart:async';
+
+import 'package:angular2/src/transform/common/asset_reader.dart';
+import 'package:angular2/src/transform/common/code/source_module.dart';
+import 'package:angular2/src/transform/common/names.dart';
+import 'package:angular2/src/transform/common/ng_compiler.dart';
+import 'package:angular2/src/compiler/source_module.dart';
+
+import 'package:barback/barback.dart';
+
+AssetId shimmedStylesheetAssetId(AssetId cssAssetId) => new AssetId(
+    cssAssetId.package, toShimmedStylesheetExtension(cssAssetId.path));
+
+AssetId nonShimmedStylesheetAssetId(AssetId cssAssetId) => new AssetId(
+    cssAssetId.package, toNonShimmedStylesheetExtension(cssAssetId.path));
+
+Future<Iterable<Asset>> processStylesheet(
+    AssetReader reader, AssetId stylesheetId) async {
+  final stylesheetUrl = '${stylesheetId.package}|${stylesheetId.path}';
+  final templateCompiler = createTemplateCompiler(reader);
+  final cssText = await reader.readAsString(stylesheetId);
+  final sourceModules =
+      templateCompiler.compileStylesheetCodeGen(stylesheetUrl, cssText);
+
+  var libraryIdx = 0;
+  return sourceModules.map((SourceModule module) => new Asset.fromString(
+      new AssetId.parse('${module.moduleUrl}'),
+      writeSourceModule(module,
+          libraryName: '${_getLibBase(module.moduleUrl)}${libraryIdx++}')));
+}
+
+final _unsafeCharsPattern = new RegExp(r'[^a-zA-Z0-9_]');
+String _getLibBase(String libraryName) {
+  return libraryName.replaceAll('/', '.').replaceAll(_unsafeCharsPattern, '_');
+}

modules_dart/transform/lib/src/transform/stylesheet_compiler/transformer.dart

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+library angular2.transform.stylesheet_compiler.transformer;
+
+import 'dart:async';
+
+import 'package:angular2/src/core/dom/html_adapter.dart';
+import 'package:angular2/src/transform/common/asset_reader.dart';
+import 'package:angular2/src/transform/common/logging.dart' as log;
+import 'package:angular2/src/transform/common/names.dart';
+
+import 'package:barback/barback.dart';
+
+import 'processor.dart';
+
+/// Pre-compiles CSS stylesheet files to Dart code for Angular 2.
+class StylesheetCompiler extends Transformer implements DeclaringTransformer {
+  StylesheetCompiler();
+
+  @override
+  bool isPrimary(AssetId id) {
+    return id.path.endsWith(CSS_EXTENSION);
+  }
+
+  @override
+  declareOutputs(DeclaringTransform transform) {
+    transform.declareOutput(nonShimmedStylesheetAssetId(transform.primaryId));
+    transform.declareOutput(shimmedStylesheetAssetId(transform.primaryId));
+  }
+
+  @override
+  Future apply(Transform transform) async {
+    await log.initZoned(transform, () async {
+      Html5LibDomAdapter.makeCurrent();
+      var reader = new AssetReader.fromTransform(transform);
+      var outputs = await processStylesheet(reader, transform.primaryInput.id);
+      outputs.forEach((Asset compiledStylesheet) {
+        transform.addOutput(compiledStylesheet);
+      });
+    });
+  }
+}

modules_dart/transform/pubspec.yaml

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+name: ng2_transform
+version: 0.0.0
+environment:
+  sdk: '>=1.8.0 <2.0.0'
+dependencies:
+  angular2:
+    path: ../../dist/dart/angular2
+  analyzer: '>=0.24.4 <0.27.0'
+  barback: '^0.15.2+2'
+  code_transformers: '^0.2.8'
+  dart_style: '>=0.1.8 <0.3.0'
+  glob: '^1.0.0'
+  guinness: any
+  html: '^0.12.0'
+  intl: '^0.12.4'
+  logging: '>=0.9.0 <0.12.0'
+  observe: '^0.13.1'
+  protobuf: '^0.4.2'
+  quiver: '^0.21.4'
+  source_span: '^1.0.0'
+  stack_trace: '^1.1.1'
+dev_dependencies:
+  test: '>=0.12.0 <0.13.0'

modules_dart/transform/test/transform/stylesheet_compiler/all_tests.dart

@@ -0,0 +1,96 @@
+library angular2.test.transform.stylesheet_compiler.all_tests;
+
+import 'dart:async';
+import 'dart:convert';
+
+import 'package:angular2/src/transform/stylesheet_compiler/transformer.dart';
+
+import 'package:barback/barback.dart';
+import 'package:guinness/guinness.dart';
+
+const SIMPLE_CSS = '''
+.foo {
+  width: 10px;
+}
+''';
+
+main() {
+  Html5LibDomAdapter.makeCurrent();
+  allTests();
+}
+
+allTests() {
+  StylesheetCompiler subject;
+
+  beforeEach(() {
+    subject = new StylesheetCompiler();
+  });
+
+  it('should accept CSS assets', () {
+    expect(subject.isPrimary(new AssetId('somepackage', 'lib/style.css')))
+        .toBe(true);
+  });
+
+  it('should reject non-CSS assets', () {
+    expect(subject.isPrimary(new AssetId('somepackage', 'lib/style.scss')))
+        .toBe(false);
+  });
+
+  it('should declare outputs', () {
+    var transform = new FakeDeclaringTransform()
+      ..primaryId = new AssetId('somepackage', 'lib/style.css');
+    subject.declareOutputs(transform);
+    expect(transform.outputs.length).toBe(2);
+    expect(transform.outputs[0].toString())
+        .toEqual('somepackage|lib/style.css.dart');
+    expect(transform.outputs[1].toString())
+        .toEqual('somepackage|lib/style.css.shim.dart');
+  });
+
+  it('should compile stylesheets', () async {
+    var cssFile = new Asset.fromString(
+        new AssetId('somepackage', 'lib/style.css'), SIMPLE_CSS);
+    var transform = new FakeTransform()..primaryInput = cssFile;
+    await subject.apply(transform);
+    expect(transform.outputs.length).toBe(2);
+    expect(transform.outputs[0].id.toString())
+        .toEqual('somepackage|lib/style.css.dart');
+    expect(transform.outputs[1].id.toString())
+        .toEqual('somepackage|lib/style.css.shim.dart');
+  });
+}
+
+@proxy
+class FakeTransform implements Transform {
+  final outputs = <Asset>[];
+  Asset primaryInput;
+
+  addOutput(Asset output) {
+    this.outputs.add(output);
+  }
+
+  readInputAsString(AssetId id, {Encoding encoding}) {
+    if (id == primaryInput.id) {
+      return primaryInput.readAsString(encoding: encoding);
+    }
+    throw 'Could not read input $id';
+  }
+
+  noSuchMethod(Invocation i) {
+    throw '${i.memberName} not implemented';
+  }
+}
+
+@proxy
+class FakeDeclaringTransform implements DeclaringTransform {
+  final outputs = <AssetId>[];
+  AssetId primaryId;
+
+  declareOutput(AssetId output) {
+    this.outputs.add(output);
+  }
+
+  noSuchMethod(Invocation i) {
+    throw '${i.memberName} not implemented';
+  }
+}