Throw if there is no compiler context available

pkg/front_end/test/fasta/shaker_test.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.md file.
 
 /// Tests basic functionality of the API tree-shaker.
 ///
 /// Each input file is built and tree-shaken, then we check that the set of
 /// libraries, classes, and members that are retained match those declared in an
 /// expectations file.
 ///
 /// Input files may contain markers to turn on flags that configure this
 /// runner. Currently only the following marker is recognized:
 ///   @@SHOW_CORE_LIBRARIES@@ - whether to check for retained information from
 ///      the core libraries. By default this runner only checks for members of
 ///      pkg/front_end/testcases/shaker/lib/lib.dart.
 library fasta.test.shaker_test;
 
 import 'dart:async' show Future;
 import 'dart:convert' show JSON;
 import 'dart:io' show File;
 
 export 'package:testing/testing.dart' show Chain, runMe;
 import 'package:front_end/physical_file_system.dart';
+import 'package:front_end/src/fasta/compiler_command_line.dart';
 import 'package:front_end/src/fasta/dill/dill_target.dart' show DillTarget;
 import 'package:front_end/src/fasta/deprecated_problems.dart'
     show deprecated_InputError;
 import 'package:front_end/src/fasta/kernel/kernel_outline_shaker.dart';
 import 'package:front_end/src/fasta/kernel/kernel_target.dart'
     show KernelTarget;
 import 'package:front_end/src/fasta/kernel/verifier.dart' show verifyProgram;
 import 'package:front_end/src/fasta/testing/kernel_chain.dart' show runDiff;
 import 'package:front_end/src/fasta/testing/patched_sdk_location.dart';
 import 'package:front_end/src/fasta/ticker.dart' show Ticker;
@@ skipping 56 matching lines @@
 }
 
 /// Step that extracts the test-specific options and builds the program without
 /// applying tree-shaking.
 class BuildProgram
     extends Step<TestDescription, _IntermediateData, TreeShakerContext> {
   const BuildProgram();
   String get name => "build program";
   Future<Result<_IntermediateData>> run(
       TestDescription description, TreeShakerContext context) async {
-    try {
-      var platformOutline = context.loadPlatformOutline();
-      platformOutline.unbindCanonicalNames();
-      var dillTarget = new DillTarget(
-          new Ticker(isVerbose: false),
-          context.uriTranslator,
-          new VmFastaTarget(new TargetFlags(strongMode: false)));
-      dillTarget.loader.appendLibraries(platformOutline);
-      var sourceTarget = new KernelTarget(
-          PhysicalFileSystem.instance, dillTarget, context.uriTranslator);
-      await dillTarget.buildOutlines();
+    return await CompilerCommandLine.withGlobalOptions("", [""], (_) async {
+      try {
+        var platformOutline = context.loadPlatformOutline();
+        platformOutline.unbindCanonicalNames();
+        var dillTarget = new DillTarget(
+            new Ticker(isVerbose: false),
+            context.uriTranslator,
+            new VmFastaTarget(new TargetFlags(strongMode: false)));
+        dillTarget.loader.appendLibraries(platformOutline);
+        var sourceTarget = new KernelTarget(
+            PhysicalFileSystem.instance, dillTarget, context.uriTranslator);
+        await dillTarget.buildOutlines();
 
-      var inputUri = description.uri;
-      var libUri = inputUri.resolve('lib/lib.dart');
-      sourceTarget.read(libUri);
-      sourceTarget.read(inputUri);
-      var contents = new File.fromUri(inputUri).readAsStringSync();
-      var showCoreLibraries = contents.contains("@@SHOW_CORE_LIBRARIES@@");
-      await sourceTarget.buildOutlines();
-      var program = await sourceTarget.buildProgram();
-      bool isIncluded(Uri uri) => !_isTreeShaken(uri);
-      trimProgram(program, isIncluded);
-      return pass(new _IntermediateData(inputUri, program, showCoreLibraries));
-    } on deprecated_InputError catch (e, s) {
-      return fail(null, e.error, s);
-    }
+        var inputUri = description.uri;
+        var libUri = inputUri.resolve('lib/lib.dart');
+        sourceTarget.read(libUri);
+        sourceTarget.read(inputUri);
+        var contents = new File.fromUri(inputUri).readAsStringSync();
+        var showCoreLibraries = contents.contains("@@SHOW_CORE_LIBRARIES@@");
+        await sourceTarget.buildOutlines();
+        var program = await sourceTarget.buildProgram();
+        bool isIncluded(Uri uri) => !_isTreeShaken(uri);
+        trimProgram(program, isIncluded);
+        return pass(
+            new _IntermediateData(inputUri, program, showCoreLibraries));
+      } on deprecated_InputError catch (e, s) {
+        return fail(null, e.error, s);
+      }
+    });
   }
 }
 
 /// Intermediate result from the testing chain.
 class _IntermediateData {
   /// The input URI provided to the test.
   final Uri uri;
 
   /// Program built by [BuildProgram].
   final Program program;
@@ skipping 83 matching lines @@
 }
 
 /// A special library used only to test the shaker. The suite above will
 /// tree-shake the contents of this library.
 const _specialLibraryPath = 'pkg/front_end/testcases/shaker/lib/lib.dart';
 
 /// Tree-shake dart:* libraries and the library under [_specialLibraryPath].
 bool _isTreeShaken(Uri uri) =>
     uri.isScheme('dart') ||
     Uri.base.resolveUri(uri).path.endsWith(_specialLibraryPath);