Fix HTML reporting display to show errors if done is called multiple times, or if an exception is thrown after done is called.

lib/reporters/html.js

@@ -129,7 +129,10 @@ function HTML(runner) {
   });
 
   runner.on('fail', function(test) {
-    if (test.type === 'hook') {
+    // For type = 'test' its possible that the test failed due to multiple
+    // done() calls. So report the issue here.
+    if (test.type === 'hook'
+      || test.type === 'test') {
       runner.emit('test end', test);
     }
   });

test/browser/index.html

@@ -14,6 +14,7 @@
     <script src="array.js"></script>
     <script src="../acceptance/duration.js"></script>
     <script src="../acceptance/timeout.js"></script>
+    <script src="multiple-done.js"></script>
     <script>
       onload = function(){
         mocha.checkLeaks();

test/browser/multiple-done.js

@@ -0,0 +1,16 @@
+describe('Multiple Done calls', function(){
+  it('should report an error if done was called more than once', function(done){
+    done();
+    done();
+  })
+
+  it('should report an error if an exception happened async after done was called', function (done) {
+    done();
+    setTimeout(done, 50);
+  })
+
+  it('should report an error if an exception happened after done was called', function(done){
+    done();
+    throw new Error("thrown error");
+  })
+})