Move JSON unit tests to new test API.

client/testing/unittest/unittestsuite.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.
 
 // TODO(rnystrom): This code is gradually moving from a Java/JUnit style to
 // something closer to JS/Jasmine. Eventually, the UnitTestSuite class can go
 // away completely (or become private to this library) and the only exposed API
 // will be group()/test()/expect(). Until then, both ways are supported, which
 // is why things look a bit weird in here.
 
@@ skipping 242 matching lines @@
       document.body.innerHTML = newBody.toString();
     }
 
     window.dynamic/*TODO(5389254)*/.postMessage('unittest-suite-done', '*');
   }
 }
 
 /** Creates an expectation for the given value. */
 Expectation expect(value) => new Expectation(value);
 
+/** Evaluates the given function and validates that it throws an exception. */
+void expectThrow(function) {
+  bool threw = false;
+  try {
+    function();
+  } catch (var e) {
+    threw = true;
+  }
+  Expect.equals(true, threw, 'Expected exception but none was thrown.');
+}
+
 /**
  * Creates a new test case with the given description and body. The
  * description will include the descriptions of any surrounding group()
  * calls.
  */
 void test(String spec, TestFunction body) {
   _ensureActiveSuite();
 
   _currentSuite._tests.add(new TestCase(
       _currentSuite._tests.length + 1, _fullSpec(spec), body, 0));
@@ skipping 203 matching lines @@
         </tr>""";
     if (stackTrace != null) {
       message +=
           "<tr><td></td><td colspan='2'><pre>${stackTrace}</pre></td></tr>";
     }
     fail = true;
   }
 }
 
 typedef void TestFunction();