Create an example that includes tests and how to run them. #122 (#130)

mocha-client-tests/addon/tests/lib/background-messaging.test.js

@@ -0,0 +1,11 @@
+describe('Background', function() {
+    describe('ping', function() {
+        it('should return pong in response', function() {
+            // Return a promise for Mocha using the Firefox browser API instead of chrome.
+            return browser.runtime.sendMessage({action: 'ping'})
+                .then(function(response) {
+                    expect(response).to.equal('pong');
+                });
+        });
+    });
+});

mocha-client-tests/addon/tests/lib/test.array.js

@@ -0,0 +1,8 @@
+describe('Array', function() {
+    describe('#indexOf()', function() {
+        it('should return -1 when the value is not present', function() {
+            expect([1,2,3]).to.not.contain(5);
+            expect([1,2,3]).to.not.contain(0);
+        });
+    });
+});