In webdriver.testing.jsunit, throw if the test suite is empty.

Previously, empty test suites would result in silent passes, meaning
incorrectly named tests or tests with syntax errors (which don't get
counted) would cause a false positive.

Signed-off-by: Jason Juang <juangj@google.com>

javascript/webdriver/testing/jsunit.js

@@ -77,6 +77,16 @@ webdriver.testing.jsunit.TestRunner.prototype.execute = function() {
   }
   this.screenshotCacheEl_.innerHTML = '';
   this.client_.sendInitEvent();
+
+  // This check adapted from goog.testing.TestRunner.prototype.execute.
+  if (this.isStrict() && this.testCase.getCount() == 0) {
+    this.client_.sendErrorEvent(
+        'No tests found in given test case: ' + this.testCase.getName() + ' ' +
+        'By default, the test runner fails if a test case has no tests. ' +
+        'To modify this behavior, see goog.testing.TestRunner\'s ' +
+        'setStrict() method.');
+  }
+
   this.testCase.setCompletedCallback(goog.bind(this.onComplete_, this));
   this.testCase.runTests();
 };