Improve the capture and display of syntax errors in VM tests.

test/runner/runner_test.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.
 
 @TestOn("vm")
 
 import 'dart:io';
 import 'dart:math' as math;
 
 import 'package:path/path.dart' as p;
@@ skipping 114 matching lines @@
         contains('-1: load error'),
         contains(
           '  Failed to load "${p.relative(testPath, from: _sandbox)}":\n'
           "  line 1 pos 1: unexpected token 'invalid'\n"
           "  invalid Dart file\n"
           "  ^\n")
       ]));
       expect(result.exitCode, equals(1));
     });
 
+    // This syntax error is detected lazily, and so requires some extra
+    // machinery to support.
+    test("a test file fails to parse due to a missing semicolon", () {
+      var testPath = p.join(_sandbox, "test.dart");
+      new File(testPath).writeAsStringSync("void main() {foo}");
+      var result = _runTest(["test.dart"]);
+
+      expect(result.stdout, allOf([
+        contains('-1: load error'),
+        contains(
+          '  Failed to load "${p.relative(testPath, from: _sandbox)}":\n'
+          "  line 1 pos 17: semicolon expected\n"
+          "  void main() {foo}\n"
+          "                  ^\n")
+      ]));
+      expect(result.exitCode, equals(1));
+    });
+
     // This is slightly different from the above test because it's an error
     // that's caught first by the analyzer when it's used to parse the file.
     test("a test file fails to parse", () {
       var testPath = p.join(_sandbox, "test.dart");
       new File(testPath).writeAsStringSync("@TestOn)");
       var result = _runTest(["test.dart"]);
 
       expect(result.stdout, allOf([
         contains('-1: load error'),
         contains(
@@ skipping 522 matching lines @@
       });
     });
   });
 }
 
 ProcessResult _runTest(List<String> args) =>
     runTest(args, workingDirectory: _sandbox);
 
 ProcessResult _runDart(List<String> args) =>
     runDart(args, workingDirectory: _sandbox);