fixes #219, able to compile multiple entry points

lib/src/analysis_context.dart

 // Copyright (c) 2015, 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 dev_compiler.src.analysis_context;
 
-import 'package:analyzer/file_system/file_system.dart';
-import 'package:analyzer/file_system/memory_file_system.dart';
 import 'package:analyzer/src/generated/engine.dart';
 import 'package:analyzer/src/generated/java_io.dart' show JavaFile;
 import 'package:analyzer/src/generated/sdk_io.dart' show DirectoryBasedDartSdk;
 import 'package:analyzer/src/generated/source.dart' show DartUriResolver;
 import 'package:analyzer/src/generated/source_io.dart';
-import 'package:path/path.dart' as path;
 
 import 'package:dev_compiler/strong_mode.dart' show StrongModeOptions;
 
 import 'checker/resolver.dart';
 import 'dart_sdk.dart';
 import 'multi_package_resolver.dart';
 import 'options.dart';
 
 /// Creates an [AnalysisContext] with dev_compiler type rules and inference,
 /// using [createSourceFactory] to set up its [SourceFactory].
 AnalysisContext createAnalysisContextWithSources(
     StrongModeOptions strongOptions, SourceResolverOptions srcOptions,
     {DartUriResolver sdkResolver, List fileResolvers}) {
   var srcFactory = createSourceFactory(srcOptions,
       sdkResolver: sdkResolver, fileResolvers: fileResolvers);
   return createAnalysisContext(strongOptions)..sourceFactory = srcFactory;
 }
 
 /// Creates an analysis context that contains our restricted typing rules.
 AnalysisContext createAnalysisContext(StrongModeOptions options) {
   AnalysisContextImpl res = AnalysisEngine.instance.createAnalysisContext();
-  res.libraryResolverFactory =
-      (context) => new LibraryResolverWithInference(context, options);
+  enableDevCompilerInference(res, options);
   return res;
 }
 
+/// Enables dev_compiler inference rules.
+// TODO(jmesserly): is there a cleaner way to plug this in?
+void enableDevCompilerInference(
+    AnalysisContextImpl context, StrongModeOptions options) {
+  context.libraryResolverFactory =
+      (c) => new LibraryResolverWithInference(c, options);
+}
+
 /// Creates a SourceFactory configured by the [options].
 ///
 /// Use [options.useMockSdk] to specify the SDK mode, or use [sdkResolver]
 /// to entirely override the DartUriResolver.
 ///
 /// If supplied, [fileResolvers] will override the default `file:` and
 /// `package:` URI resolvers.
 SourceFactory createSourceFactory(SourceResolverOptions options,
-    {DartUriResolver sdkResolver, List fileResolvers}) {
+    {DartUriResolver sdkResolver, List<UriResolver> fileResolvers}) {
   var sdkResolver = options.useMockSdk
       ? createMockSdkResolver(mockSdkSources)
       : createSdkPathResolver(options.dartSdkPath);
 
   var resolvers = [];
   if (options.customUrlMappings.isNotEmpty) {
     resolvers.add(new CustomUriResolver(options.customUrlMappings));
   }
   resolvers.add(sdkResolver);
-  if (options.useImplicitHtml) {
-    resolvers.add(_createImplicitEntryResolver(options));
-  }
-  if (fileResolvers == null) {
-    fileResolvers = [new FileUriResolver()];
-    fileResolvers.add(options.useMultiPackage
-        ? new MultiPackageResolver(options.packagePaths)
-        : new PackageUriResolver([new JavaFile(options.packageRoot)]));
-  }
+  if (fileResolvers == null) fileResolvers = createFileResolvers(options);
   resolvers.addAll(fileResolvers);
   return new SourceFactory(resolvers);
 }
 
+List<UriResolver> createFileResolvers(SourceResolverOptions options) {
+  return [
+    new FileUriResolver(),
+    options.useMultiPackage
+        ? new MultiPackageResolver(options.packagePaths)
+        : new PackageUriResolver([new JavaFile(options.packageRoot)])
+  ];
+}
+
 /// Creates a [DartUriResolver] that uses a mock 'dart:' library contents.
 DartUriResolver createMockSdkResolver(Map<String, String> mockSources) =>
     new MockDartSdk(mockSources, reportMissing: true).resolver;
 
 /// Creates a [DartUriResolver] that uses the SDK at the given [sdkPath].
 DartUriResolver createSdkPathResolver(String sdkPath) => new DartUriResolver(
     new DirectoryBasedDartSdk(
         new JavaFile(sdkPath), /*useDart2jsPaths:*/ true));
-
-UriResolver _createImplicitEntryResolver(SourceResolverOptions options) {
-  var entry = path.absolute(SourceResolverOptions.implicitHtmlFile);
-  var src = path.absolute(options.entryPointFile);
-  var provider = new MemoryResourceProvider();
-  provider.newFile(
-      entry, '<body><script type="application/dart" src="$src"></script>');
-  return new ExistingSourceUriResolver(new ResourceUriResolver(provider));
-}
-
-/// A UriResolver that continues to the next one if it fails to find an existing
-/// source file. This is unlike normal URI resolvers, that always return
-/// something, even if it is a non-existing file.
-class ExistingSourceUriResolver implements UriResolver {
-  final UriResolver resolver;
-  ExistingSourceUriResolver(this.resolver);
-
-  Source resolveAbsolute(Uri uri) {
-    var src = resolver.resolveAbsolute(uri);
-    return src.exists() ? src : null;
-  }
-  Uri restoreAbsolute(Source source) => resolver.restoreAbsolute(source);
-}