Parse command-line options into a list of test configurations.

tools/testing/dart/test_runner.dart

 // Copyright (c) 2011, 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("test_runner");
 
 #import("status_file_parser.dart");
 #import("test_progress.dart");
 
 /**
@@ skipping 26 matching lines @@
     return 'dart_bin';
   } else if (configuration['component'] == 'dartc') {
     return 'dartc';
   } else {
     throw "Unknown executable for: ${configuration['component']}";
   }
 }
 
 
 String getDartShellFileName(Map configuration) {
-  return getBuildDir(configuration) + getExecutableName(configuration);
+  var name = getBuildDir(configuration) + getExecutableName(configuration);
+  if (!(new File(name)).existsSync()) {
+    throw "Executable '$name' does not exist";
+  }
+  return name;
 }
 
 
 class TestCase {
   String executablePath;
   List<String> arguments;
   String commandLine;
   String displayName;
   TestOutput output;
   Set<String> expectedOutcomes;
@@ skipping 133 matching lines @@
       numProcesses++;
     }
   }
 
   runTest(TestCase test) {
     progress.testAdded();
     tests.add(test);
     tryRunTest();
   }
 }