Scaffolding for testing incremental compilation.

dart/pkg/dart2js_incremental/lib/dart2js_incremental.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 dart2js_incremental;
 
 import 'dart:async' show
     Future;
 
 import 'dart:profiler' show
@@ skipping 29 matching lines @@
   final Uri libraryRoot;
   final Uri packageRoot;
   final CompilerInputProvider inputProvider;
   final DiagnosticHandler diagnosticHandler;
   final List<String> options;
   final CompilerOutputProvider outputProvider;
   final Map<String, dynamic> environment;
 
   Compiler _compiler;
 
+  bool get compilerWasCancelled => _compiler.compilerWasCancelled;
+
   IncrementalCompiler({
       this.libraryRoot,
       this.packageRoot,
       this.inputProvider,
       this.diagnosticHandler,
       this.options,
       this.outputProvider,
       this.environment}) {
     if (libraryRoot == null) {
       throw new ArgumentError('libraryRoot is null.');
     }
     if (inputProvider == null) {
       throw new ArgumentError('inputProvider is null.');
     }
     if (diagnosticHandler == null) {
       throw new ArgumentError('diagnosticHandler is null.');
     }
   }
 
   Future<bool> compile(Uri script) {
-    List<String> options = new List<String>.from(this.options);
+    List<String> options = this.options == null
+        ? <String> [] : new List<String>.from(this.options);
     options.addAll(INCREMENTAL_OPTIONS);
     Future<Compiler> future = reuseCompiler(
         cachedCompiler: _compiler,
         libraryRoot: libraryRoot,
         packageRoot: packageRoot,
         inputProvider: inputProvider,
         diagnosticHandler: diagnosticHandler,
         options: options,
         outputProvider: outputProvider,
         environment: environment);
     return future.then((Compiler compiler) {
       _compiler = compiler;
       return compiler.run(script);
     });
   }
 }