RedHatTraining/rht-labs-docs.git

Merge pull request #238 from Tompage1994/master

Donal Spring

2018-07-03 e5f13cc4142057a9114e8ebd172c2644786d036c

commit \| author \| age
15c296	1	# Revenge Of The Automated Testing
5a16fd	2
867471	3	> The purpose of this exercise is to develop and validate a new feature using TDD; and to promote the assured feature through the pipeline.
01245c	4
9e07af	5	![comic-header](../images/exercise3/comic-header.png)
RH	6
	7	[Image Source](https://cdn-images-1.medium.com/max/1600/1*wF_fSCH-gLYfMbkwb3gR2w.png)
	8
aea5c5	9	## Introduction to TDD.
D	10
	11	> _Here is a brief introduction of TDD and why we use it._
	12
	13	Test Driven Development (TDD) is a software development process that relies on the repetition of a very short development cycle. Requirements are turned into test cases, where the software is developed to pass the tests. In other words, it creates a safety net that serves to keep the developer's problems/bugs at bay while enabling the developer to refactor efficiently. This is opposed to software development that allows software to be added that is not proven to meet requirements.
	14
	15	The TDD cycle can be illustrated with the following diagram;
	16	![TDD-diagram](../images/exercise3/TDD-lifecycle.jpg)
	17
5e7a31	18	### The TDD Cycle
aea5c5	19
D	20	1. `Write a test` -
853f0c	21	In TDD a new feature begins by writing a test. Write a test that clearly defines a function or one that provides an improvement to an existing function. It's important the developer clearly understands the feature's specification and requirements, or the feature could be wrong from the get-go.
aea5c5	22
D	23	2. `Test Fails` -
5e7a31	24	When a test is first implemented it is expected to fail. This failure validates the test is working correctly as the feature is yet to be implemented.
aea5c5	25
D	26	3. `Write code to make test pass` -
	27	This step involves implementing the feature to pass the failed test. Code written at this stage may be inelegant and still pass the test, however this is acceptable as TDD is a recursive cycle which includes code refactoring.
	28
	29	4. `Code Passes tests` -
	30	If all tests pass, the developer can be confident that the new code meets the test requirements.
	31
	32	5. `Refactor` -
f23c14	33	The refactoring step will allow the developer to clean up their code without changing its behaviour. Not changing the behaviour should ensure the tests still pass. The process of refactoring can include; removal of duplication, renaming of object, class, module, variable and method names to clearly represent their current purpose and use, decoupling of functionality and increasing code cohesion.
aea5c5	34
D	35	6. `Repeat` -
	36	Starting with another new test, the cycle is then repeated to push forward the functionality. The size of the steps should always be small, with as few as 1 to 10 edits between each test run. If new code does not rapidly satisfy a new test, or other tests fail unexpectedly, the programmer should undo or revert in preference to excessive debugging.
	37
	38	### Testing Bananalogy
5e7a31	39	Explanation of Mocha and JS test syntax through Bananalogy! Imagine for a moment; we're not building software but creating a bowl of fruit. To create a `Bunch of Bananas` component for our fruit bowl we could start with our tests as shown below.
aea5c5	40	![bdd-bananas](../images/exercise3/bdd-bananas.png)
D	41	* `describe` is used to group tests together. The string `"a bunch of ripe bananas"` is for human reading and allows you to identify tests.
	42	* `it` is a statement that contains a test. It should contain an assertion such as `expect` or `should`. It follows the syntax of `describe` where the string passed in identifies the statement.
01245c	43
D	44	---
5a16fd	45
D	46	## Learning Outcomes
01245c	47
5a16fd	48	As a learner you will be able to
01245c	49
142de4	50	* Understand the why behind TDD
936424	51	* Implement a feature using TDD for front end and backend
142de4	52	* Write end to end tests for the feature and run them in CI
5a16fd	53
D	54	## Tools and Frameworks
01245c	55
5a16fd	56	> Name of tool - short description and link to docs or website
D	57
142de4	58	1. [Jest](https://facebook.github.io/jest/) - Zero configuration testing platform
D	59	Jest is used by Facebook to test all JavaScript code including React applications. One of Jest's philosophies is to provide an integrated "zero-configuration" experience. We observed that when engineers are provided with ready-to-use tools, they end up writing more tests, which in turn results in more stable and healthy code bases.
	60	1. [Vue Test Utils](https://vue-test-utils.vuejs.org/en/) - Vue Test Utils is the official unit testing utility library for Vue.js.
	61	1. [Nightwatch.js](http://nightwatchjs.org/) - Nightwatch.js is an easy to use Node.js based End-to-End (E2E) testing solution for browser based apps and websites. It uses the powerful W3C WebDriver API to perform commands and assertions on DOM elements.
	62	1. [Mocha](https://mochajs.org/) - Mocha is a feature-rich JavaScript test framework running on Node.js and in the browser, making asynchronous testing simple and fun. Mocha tests run serially, allowing for flexible and accurate reporting, while mapping uncaught exceptions to the correct test cases. Hosted on GitHub.
5e7a31	63	1. [Sinon](http://sinonjs.org/) - Standalone test spies, stubs and mocks for JavaScript.
142de4	64	Works with any unit testing framework.
5a16fd	65
D	66	## Big Picture
01245c	67
5a16fd	68	This exercise begins cluster containing blah blah
D	69
01245c	70	---
5a16fd	71
D	72	## 10,000 Ft View
	73
a9efee	74	> The goal of this exercise is to add a new component to the application using TDD to create and validate its behaviour. The User story we have been given is as follows:
5a16fd	75
5e7a31	76	As a doer I want to mark todos as important so that I can keep track of and complete high priority todos first
01245c	77
142de4	78	_Acceptance Criteria_
D	79	- [ ] should be doable with a single click
	80	- [ ] should add a red flag against the todo when marked important
	81	- [ ] should remove the red colour flag on the flag when important removed
	82	- [ ] should not affect existing todos
	83
	84	_On page load:_
	85	- [ ] should display existing todos that are not marked important
	86	- [ ] should display existing todos that are marked important with an red flag
5a16fd	87
D	88	## Step by Step Instructions
3050f4	89	> This is a fairly structured guide with references to exact filenames and sections of text to be added.
5a16fd	90
01245c	91	### Part 1 - Tests in our Pipeline
936424	92	> _In this part we will get familiar with the layout of our tests. We will also improve the pipeline created already by adding some unit tests for the front end & backend along with some end to end tests (e2e) to validate the full solution_
5a16fd	93
752f2a	94	#### 1a - FE Unit tests
936424	95	> In this exercise we will execute our test for the front end locally. Once verified we will add them to Jenkins.
d1565e	96
655873	97	2. Before linking our automated testing to the pipeline we'll first ensure the tests run locally. Change to the `todolist-fe` directory and run `test`.
3050f4	98	```bash
58480f	99	cd todolist-fe
D	100	```
	101	```bash
	102	npm run test
3050f4	103	```
5e7a31	104	<p class="tip" >
8fc8df	105	`test` is an alias used that runs `vue-cli-service test` from the scripts object in `package.json`
3050f4	106	</p>
aea5c5	107	![screenshot-scripts](../images/exercise3/screenshot-scripts.png)
D	108
936424	109	2. This command will run all `spec.js` files. Our test files are stored in the following places. There are 12 front end test files stored in these directories: `todolist-fe/tests/unit/vue-components/` & `todolist-fe/tests/unit/javascript/*`
d1565e	110
3050f4	111	2. You should see an output similar to the following. The above command has run a test suite for every `*.spec.js` file. The table generated in the terminal shows the code coverage. We're going to be focusing on the unit tests for now.
aea5c5	112	![test-run-locally](../images/exercise3/test-run-locally.png)
3050f4	113
5e7a31	114	2. Repeat the same process for `todolist-api` and verify that all the tests run. If you have an ExpressJS server already running from previous exercise; you should kill it before running the tests. The `mocha` test suite will launch a dev server for running the tests. There are 2 API test files: `todolist-api/server/api/todo/todo.spec.js` & `todolist-api/server/mocks/mock-routes.spec.js` for our API and the Mocks server.
3050f4	115	```bash
58480f	116	cd todolist-api
D	117	```
	118	```bash
	119	npm run test
3050f4	120	```
b81187	121
5e7a31	122	2. Navigate to your instance of Jenkins at `https://jenkins-<YOUR_NAME>-ci-cd.apps.lader.rht-labs.com/`.
3050f4	123	Click on `dev-todolist-fe-build` and then click the `configure` button on the left-hand side.
aea5c5	124	![jenkins-configure-job](../images/exercise3/jenkins-configure-job.png)
3050f4	125
140a4a	126	2. Scroll to the `Build` part of the configuration page and add `npm run test` below `npm install`.
aea5c5	127	![jenkins-build-step](../images/exercise3/jenkins-build-step.png)
3050f4	128
e1ba4f	129	2. Scroll to the `Post-build Actions` section and click `Add post-build action`. Select `Publish xUnit test result report` (Jenkins might place this at the top of the `Post-build Actions` list).
aea5c5	130	![xunit-action](../images/exercise3/xunit-action.png)
b81187	131
A	132	2. Click the `Add` button under `Publish xUnit test result report` and select `JUnit`. In the pattern field enter `test-report.xml`. In the `Failed Tests Thresholds` input box enter 0 under `Red Ball Total`. It should look a little something like this:
aea5c5	133	![post-build-actions](../images/exercise3/post-build-actions.png)
b81187	134
0976ea	135	2. Click `save` or `apply` at the bottom to save the changes. Run the `dev-todolist-fe-build` job and verify that this passes and the `build` and `bake` jobs are both triggered.
b81187	136
a9627c	137	#### (Optional) Failing the tests
65ddc2	138	> _If you're not very confident in your technical ability and want don't want to do the TDD lab; feel free to just do this next section. If you are confident jump on to the e2e testing section below_
a9627c	139
d82125	140	2. We're now going to deliberately fail a test to ensure that `bake` and `deploy` jobs aren't triggered if any tests fail. Open the `todolist-fe` source code in your favourite editor. Open `ListOfTodos.spec.js` in `/tests/unit/vue-components` and head to `line 39`. Add `not.` before `toHaveBeenCalled()` to fail the test.
aea5c5	141	![change-test-to-fail](../images/exercise3/change-test-to-fail.png)
b81187	142
0976ea	143	2. Push this to Gitlab and run the build job.
b81187	144	```bash
58480f	145	git add .
D	146	```
	147	```bash
	148	git commit -m "TEST - failing build with tests"
	149	```
	150	```bash
	151	git push
b81187	152	```
A	153
5e7a31	154	2. Rerun the `dev-todolist-fe-build` job. It should have failed and not run any other jobs.
aea5c5	155	![jenkins-with-failing-build](../images/exercise3/jenkins-with-failing-build.png)
b81187	156
5da0fd	157	2. You can examine the test results on the jobs home page. Drill down into the tests to see which failed and other useful stats
D	158	![fe-test-fails](../images/exercise3/fe-test-fails.png)
	159
ff561b	160	2. Undo the changes you made to the `ListOfTodos.spec.js` file, commit your code and rerun the build. This should trigger a full `build --> bake --> deploy` of `todolist-fe`.
e1ba4f	161
a9627c	162	#### 1b - End to End tests (e2e)
cad21a	163	> _Unit tests are a great way to get immediate feedback as part of testing an application. End to end tests that drive user behaviour are another amazing way to ensure an application is behaving as expected._
d1565e	164
f9d113	165	In this exercise we will add a new stage to our pipeline called `dev-todolist-fe-e2e` that will run after the deploy has been completed. End to end tests will use Nightwatchjs to orchestrate a selenium webdriver instance that controls the web browser; in this case Chrome!
D	166
	167	2. Let's start by checking our tests execute locally. On the terminal move to the `todolist-fe` folder. Our end to end tests are stored in `tests/e2e/specs/`. The vuejs cli uses nightwatch and comes pre-configured to run tests against Chrome. We have created some additional configuration in the root of the project `nightwatch.config.js` to run headless in CI mode on Jenkins.
	168	```bash
58480f	169	cd todolist-fe
f9d113	170	```
D	171
	172	2. Run the tests locally by executing the following. This should start the dev server and run the test. You may see the browser pop up and close while tests execute.
	173	```bash
58480f	174	npm run e2e
f9d113	175	```
4ce512	176	![local-e2e](../images/exercise3/local-e2e.png)
f9d113	177
4ce512	178	2. With tests executing locally; let's add them to our Jenkins pipeline. To do this; we'll create a new job and connect it up to our `todolist-fe` jobs. Open Jenkins and create a `New Item` called `dev-todolist-fe-e2e`. Make this Job `Freestyle`.
f9d113	179
e1ba4f	180	2. On the configuration page (under the general tab); Set the Label for the job to run on as `jenkins-slave-npm`. Check the box marking the build parameterised and add a String parameter of `BUILD_TAG` as done before
4ce512	181	![e2e-general](../images/exercise3/e2e-general.png)
d1565e	182
4ce512	183	2. On the Source Code Management tab; set the source code to git and add the url to your `todolist-fe` app. Set the branch to `refs/tags/${BUILD_TAG}`
D	184	![e2e-git](../images/exercise3/e2e-git.png)
	185
e1ba4f	186	2. Set `Color ANSI Console Output` on the `Build Environment` section
4ce512	187
45eb81	188	2. On the Build section; add a build step to execute shell and fill in the following substituting `<YOUR_NAME>` accordingly:
4ce512	189	```bash
45eb81	190	export E2E_TEST_ROUTE=todolist-fe-<YOUR_NAME>-dev.apps.lader.rht-labs.com
7a3088	191	npm install
D	192	npm run e2e:ci
4ce512	193	```
D	194	![e2e-steps](../images/exercise3/e2e-steps.png)
	195
e1ba4f	196	2. Add a Post Build action to `Publish Junit test result report`. Add `reports/e2e/specs/*.xml` to the report location and save the configuration to be brought back to the Job's homepage.
4ce512	197	![e2e-post-build](../images/exercise3/e2e-post-build.png)
D	198
e1ba4f	199	2. We want to connect the e2e job we just created to our dev pipleline by editing the post build actions on `dev-todolist-fe-deploy` job. Open the `dev-todolist-fe-deploy` job and hit `configure`. In the `Post-build actions` section of this job add a `Trigger parameterised build` on other jobs. Set the `Projects to build` to be `dev-todolist-fe-e2e`. Add a Parameter and set the it to the `Current build parameters`. Save the settings.
a47ec2	200	![e2e-trigger](../images/exercise3/e2e-trigger.png)
D	201
b62fab	202	2. Run the pipeline from the beginning to see the tests executed (two executions will show tests scores on the graph!).
d1565e	203
142de4	204	### Part 2 - TodoList new feature
d1565e	205	> _In this exercise we will introduce a new feature to create an important flag on the todos. In order to be able to build and test our feature we will use TDD_
D	206
142de4	207	As a doer I want to mark todos as important so that I can keep track of and complete high prirority todos first
d1565e	208
142de4	209	_Acceptance Criteria_
D	210	- [ ] should be doable with a single click
	211	- [ ] should add a red flag against the todo when marked important
	212	- [ ] should remove the red colour flag on the flag when important removed
	213	- [ ] should not affect existing todos
d1565e	214
142de4	215	_On page load:_
D	216	- [ ] should display existing todos that are not marked important
	217	- [ ] should display existing todos that are marked important with an red flag
d1565e	218
752f2a	219	#### 2a - Create todolist-api tests
142de4	220	> Using [Mocha](https://mochajs.org/) as our test runner; we will now write some tests for backend functionality to persist our important-flag. The changes required to the backend are minimal but we will use TDD to create our test first, then implement the functionality.
01245c	221
D	222	3. Create a new branch in your `todolist-api` app for our feature and push it to the remote
d1565e	223	```bash
58480f	224	git checkout -b feature/important-flag
D	225	```
	226	```bash
	227	git push -u origin feature/important-flag
5a16fd	228	```
D	229
01245c	230	3. Navigate to the `server/api/todo/todo.spec.js` file. This contains all of the existing todo list api tests. These are broken down into simple `describe("api definition", function(){})` blocks which is BDD speak for how the component being tested should behave. Inside of each `it("should do something ", function(){})` statements we use some snappy language to illustrate the expected behaviour of the test. For example a `GET` request of the api is described and tested for the return to be of type Array as follows.
D	231	```javascript
	232	describe("GET /api/todos", function() {
	233	it("should respond with JSON array", function(done) {
	234	request(app)
	235	.get("/api/todos")
	236	.expect(200)
	237	.expect("Content-Type", /json/)
	238	.end(function(err, res) {
	239	if (err) return done(err);
	240	// Test goes here
	241	res.body.should.be.instanceof(Array);
	242	done();
	243	});
142de4	244	});
01245c	245	});
D	246	```
	247	where:
775c6b	248	- `describe` is used to group tests together into a collection asserting some feature; for example the get all todos api.
D	249	- `it` is an individual test statement and should contain an `expect` or a `should` statement asserting behaviour of the API under test.
	250	- `request` is a library for making http calls to the api.
	251	- `.expect(200)` asserts the HTTP Return Code
	252	- `res.body.should.be.instanceof(Array);` is the actual test call
	253	- `done();` tells the test runner that `mocha` has finished execution. This is needed as the http calls are asynchronous.
5a16fd	254
5e7a31	255	3. With this knowledge; let's implement our test for the `important` flag. We expect the front end to introduce a new property on each `todo` that gets passed to the backend called `important`. The API will need to handle this new property and pass it into the mongodb. Let's begin implementing this functionality by writing our test case. Navigate to the `PUT /api/todos` section of the `server/api/todo/todo.spec.js` test file (which should be at the bottom)
775c6b	256	![todo-api-tests](../images/exercise3/todo-api-tests.png)
01245c	257
775c6b	258	3. Before writing our test; let's first make sure all the existing tests are passing.
142de4	259	```bash
58480f	260	npm run test
01245c	261	```
D	262
775c6b	263	3. With all the tests passing; let's add our new one. For ease of completing this exercise a template of a new test has been written at the very end of the file (just below the ` // Exercise 3 test case!` comment). A PUT request responds in our API with the data that it has just updated. So provided that MongoDB accepted the change, the API will respond with an object that has the `important` property on it. To write our test; edit the template test by completing the following:
9f3a7a	264	* Edit the `it("should ...")` to describe the important flag we're testing
01245c	265	* Edit the `.send()` to include `important: true` property
775c6b	266	* Edit the `.expect()` to be `.expect(200)`
01245c	267	* Add a new test assertion to check that `res.body.important` is `true` below the `// YOUR TEST GO HERE` line.
D	268	```javascript
775c6b	269	// Exercise 3 test case!
142de4	270	it("should mark todo as important and persist it", function(done) {
01245c	271	request(app)
D	272	.put("/api/todos/" + todoId)
142de4	273	.send({
D	274	title: "LOVE endpoint/server side testing!",
	275	completed: true,
	276	important: true
	277	})
01245c	278	.expect(200)
D	279	.expect("Content-Type", /json/)
	280	.end(function(err, res) {
142de4	281	if (err) return done(err);
D	282	res.body.should.have.property("_id");
	283	res.body.title.should.equal("LOVE endpoint/server side testing!");
	284	// YOUR TEST GO HERE
	285	res.body.important.should.equal(true);
	286	done();
01245c	287	});
142de4	288	});
01245c	289	```
D	290
142de4	291	3. Run your test. It should fail.
D	292	```bash
58480f	293	npm run test
01245c	294	```
D	295	![fail-mocha](../images/exercise3/fail-mocha.png)
	296
9f3a7a	297	3. With our test now failing; let's implement the feature. This is quite a simple change - we first need to update the `server/api/todo/todo.model.js`. Add an additional property on the schema called `important` and make its type Boolean.
01245c	298	```javascript
D	299	const TodoSchema = new Schema({
142de4	300	title: String,
D	301	completed: Boolean,
	302	important: Boolean
01245c	303	});
D	304	```
9f3a7a	305
5e7a31	306	3. Next we need to update the `server/config/seed.js` file so that the pre-generated todos have an important property. Add `important: true` below `completed: ` for each object. Don't forget to add a comma at the end of the `completed: ` line.
9f3a7a	307	![api-add-seed-important](../images/exercise3/api-add-seed-important.png)
01245c	308
142de4	309	3. With your changes to the Database schema updated; re-run your tests.
D	310	```bash
58480f	311	npm run test
01245c	312	```
D	313
142de4	314	3. Commit your code to the `feature/important-flag` branch and then merge onto the `develop` branch as follows
01245c	315	<p class="tip">
D	316	NOTE - At this point in a residency we would peer review the code before pushing it to develop or master branch!
	317	</p>
142de4	318	```bash
58480f	319	git add .
D	320	```
	321	```bash
	322	git commit -m "ADD backend schema updates"
	323	```
	324	```bash
	325	git push
	326	```
	327	```bash
	328	git checkout develop
	329	```
	330	```bash
	331	git merge feature/important-flag
	332	```
	333	```bash
	334	git push
01245c	335	```
D	336
1329f3	337	3. After pushing your changes; start back up the `todolist-api` app on a new terminal session
D	338	```bash
58480f	339	npm run start
1329f3	340	```
D	341
936424	342	#### 2b - Create todolist-fe tests
5e7a31	343	> Using [Jest](https://facebook.github.io/jest/) as our test runner and the `vue-test-utils` library for managing our vue components; we will now write some tests for front end functionality to persist our important-flag. The changes required to the front end are quite large but we will use TDD to create our test first, then implement the functionality.
01245c	344
853f0c	345	Our TodoList App uses `vuex` to manage the state of the app's todos and `axios` HTTP library to connect to the backend. `Vuex` is an opinionated framework for managing application state and has some key design features you will need to know to continue with the exercise.
01245c	346
a9efee	347	In `vuex` the application state is managed by a `store`. The `store` houses all the todos we have retrieved from the backend as well as the `getter` methods for our array of `todos`. In order to make changes to the store, we could call the store directly and update each todo item but as earlier said; vuex is an opinionated module with its own way of updating the store. It is bad practice to call the store directly.
142de4	348
853f0c	349	There are two parts of the lifecycle to updating the store, the `actions` & `mutations`. When the user clicks a todo to mark it as complete; the `actions` are called. An action could involve a call to the backend or some pre-processing of the data. Once this is done, the change is committed to the store by calling the `mutation` function. A store should only ever be manipulated through a mutation function. Calling the mutation will then update the todo object in the app's local store for rendering in the view.
142de4	350
D	351	For example; when marking a todo as done in the UI, the following flow occurs
1329f3	352	* The `TodoItem.vue` calls the `markTodoDone()` function which dispatches an event to the store.
D	353	* This calls the `updateTodo()` function in the `actions.js` file
	354	* The action will update the backend db (calling our `todolist-api`) with our updated todo object.
	355	* The action will commit the change to the store by calling the mutation method `MARK_TODO_COMPLETED`
	356	* The `MARK_TODO_COMPLETED` will directly access the store object and update it with the new state value
	357	* The `ListOfTodos.vue` component is watching the store for changes and when something gets updated it re-renders the `TodoItem.vue`.
	358
	359	The implementation of our `important` flag will follow this same flow.
142de4	360
D	361	3. Let's implement our feature by first creating a branch. Our new feature, important flag will behave in the same way as the `MARK_TODO_COMPLETED`. Create a new branch in your `todolist-fe` app for our feature and push it to the remote
01245c	362	```bash
58480f	363	git checkout -b feature/important-flag
D	364	```
	365	```bash
	366	git push -u origin feature/important-flag
01245c	367	```
d1565e	368
5e7a31	369	3. Let's get our tests running by executing a `--watch` on our tests. This will keep re-running our tests everytime there is a file change. It is handy to have this running in a new terminal session.
142de4	370	```bash
58480f	371	npm run test -- --watch
142de4	372	```
D	373
1329f3	374	3. All the tests should be passing when we begin. If `No tests found related to files changed since last commit` is on show; hit `a` on the terminal to re-run `all` tests.
D	375	![rerun-all](../images/exercise3/rerun-all.png)
	376
867471	377	3. There are three places we will add new tests to validate our function behaves as expected against the acceptance criteria from the Feature Story supplied to us. We will need to write tests for our `TodoItem.vue` to handle having a red flag and that it is clickable. Our app is going to need to persist the changes in the backend so we'll want to make changes to our `actions.js` and `mutations.js` to keep the api and local copy of the store in sync. Let's start with our `TodoItem.vue` component. Open the `tests/unit/vue-components/TodoItem.spec.js` file. This has been templated with some example test to correspond with our A/Cs for speed of doing the exercise. Find the describe block for our important flag tests. It is setup already with a `beforeEach()` hook for test setup.
142de4	378	![important-flag-before](../images/exercise3/important-flag-before.png)
D	379
a9efee	380	3. Each of our test cases has its skeleton in place already for example the `TodoItem.vue` component takes a property of `todos` when rendering. This setup is already done for each of our tests so all we have to do is fill in our assertions.
142de4	381	![todoitem-skeleton-tests](../images/exercise3/todoitem-skeleton-tests.png)
D	382
1329f3	383	3. Let's implement the first test `it("should render a button with important flag"`. This test will assert if the button is present on the page and it contains the `.important-flag` CSS class. To implement this; add the `expect` statement as follows below the `// TODO - test goes here!` comment.
142de4	384	```javascript
D	385	it("should render a button with important flag", () => {
	386	const wrapper = mount(TodoItem, {
	387	propsData: { todoItem: importantTodo }
	388	});
	389	// TODO - test goes here!
	390	expect(wrapper.find(".important-flag").exists()).toBe(true);
	391	});
	392	```
	393
	394	3. Save the file and we should see in our test watch the test case has started failing because we have not yet implemented the feature!
	395	![todoitem-fail-test](../images/exercise3/todoitem-fail-test.png)
	396
9f3a7a	397	3. With a basic assertion in place, let's continue on to the next few tests. We want the important flag to be red when an item in the todolist is marked accordingly. Conversely we want it to be not red when false. Let's create a check for `.red-flag` CSS property to be present when important is true and not when false. Complete the `expect` statements in your test file as shown below for both tests.
142de4	398	```javascript
D	399	it("should set the colour to red when true", () => {
	400	const wrapper = mount(TodoItem, {
	401	propsData: { todoItem: importantTodo }
	402	});
	403	// TODO - test goes here!
	404	expect(wrapper.find(".red-flag").exists()).toBe(true);
	405	});
	406	it("should set the colour to not red when false", () => {
	407	importantTodo.important = false;
	408	const wrapper = mount(TodoItem, {
	409	propsData: { todoItem: importantTodo }
	410	});
	411	// TODO - test goes here!
	412	expect(wrapper.find(".red-flag").exists()).toBe(false);
	413	});
	414	```
	415
4c8a9b	416	3. Finally, we want to make the flag clickable and for it to call a function to update the state. The final test in the `TodoItem.spec.js` we want to create should simulate this behaviour. Implement the `it("call markImportant when clicked", () ` test by first simulating the click of our important-flag and asserting the function `markImportant()` to write is executed.
142de4	417	```javascript
4c8a9b	418	it("call markImportant when clicked", () => {
142de4	419	const wrapper = mount(TodoItem, {
D	420	methods,
	421	propsData: { todoItem: importantTodo }
	422	});
	423	// TODO - test goes here!
	424	const input = wrapper.find(".important-flag");
	425	input.trigger("click");
	426	expect(methods.markImportant).toHaveBeenCalled();
	427	});
	428	```
	429
1329f3	430	3. With our tests written for the feature's UI component, let's implement our code to pass the tests. Explore the `src/components/TodoItem.vue`. Each vue file is broken down into 3 sections
142de4	431	* The `<template></template>` contains the HTML of our component. This could include references to other Components also
D	432	* The `<script></script>` contains the JavaScript of our component and is essentially the logic for our component. It defines things like `properties`, `methods` and other `components`
	433	* The `<style></style>` contains the encapsulated CSS of our component
1329f3	434
853f0c	435	3. Underneath the `</md-list-item>` tag, let's add a new md-button. Add an `.important-flag` class on the `md-button` and put the svg of the flag provided inside it.
142de4	436	```html
D	437	</md-list-item>
867471	438	<!-- TODO - SVG for use in Exercise3 -->
142de4	439	<md-button class="important-flag">
D	440	<svg height="24" viewBox="0 0 24 24" width="24" xmlns="http://www.w3.org/2000/svg" ><path d="M0 0h24v24H0z" fill="none"/><path d="M14.4 6L14 4H5v17h2v-7h5.6l.4 2h7V6z"/></svg>
	441	</md-button>
	442	```
	443
	444	3. We should now see the first of our failing tests has started to pass. Running the app locally (using `npm run serve`) should show the flag appear in the UI. It is clickable but won't fire any events and the colour is not red as per our requirement. Let's continue to implement the colour change for the flag. On our `<svg/>` tag, add some logic to bind the css to the property of a `todo.important` by adding ` :class="{'red-flag': todoItem.important}" `. This logic will apply the CSS class when `todo.important` is true.
	445	```html
	446	<md-button class="important-flag">
	447	<svg :class="{'red-flag': todoItem.important}" height="24" viewBox="0 0 24 24" width="24" xmlns="http://www.w3.org/2000/svg" ><path d="M0 0h24v24H0z" fill="none"/><path d="M14.4 6L14 4H5v17h2v-7h5.6l.4 2h7V6z"/></svg>
	448	</md-button>
	449	```
	450
853f0c	451	3. More tests should now be passing. Let's wire the click of the flag to an event in Javascript. In the methods section of the `<script></script>` tags in the Vue file, implement the `markImportant()`. We want to wire this to the action to updateTodo, just like we have in the `markCompleted()` call above it. We also need to pass an additional property to this method called `important`
142de4	452	```javascript
D	453	markImportant() {
867471	454	// TODO - FILL THIS OUT IN THE EXERCISE
142de4	455	this.$store.dispatch("updateTodo", {id: this.todoItem._id, important: true});
D	456	console.info("INFO - Mark todo as important ", this.todoItem.important);
	457	},
	458	```
	459
853f0c	460	3. Let's connect the click button in the DOM to the Javascript function we've just created. In the template, add a click handler to the md-button to call the function `markImportant()` by adding ` @click="markImportant()"` to the `<md-button>` tag
142de4	461	```html
867471	462	<!-- TODO - SVG for use in Exercise3 -->
142de4	463	<md-button class="important-flag" @click="markImportant()">
D	464	<svg :class="{'red-flag': todoItem.important}" height="24" viewBox="0 0 24 24" width="24" xmlns="http://www.w3.org/2000/svg" ><path d="M0 0h24v24H0z" fill="none"/><path d="M14.4 6L14 4H5v17h2v-7h5.6l.4 2h7V6z"/></svg>
	465	</md-button>
	466	```
9f3a7a	467
A	468	3. Finally - we need to make it so that when a new todo item is created it will have an important property. Head to `store/actions.js` and add `important: false` below `completed: false` in the `addTodo(){}` action.
	469	![fe-add-actions-important](../images/exercise3/fe-add-actions-important.png)
	470
142de4	471
5e7a31	472	3. The previously failing tests should have started to pass now. With this work done, let's commit our code. On the terminal, run
142de4	473	```bash
58480f	474	git add .
D	475	```
	476	```bash
	477	git commit -m "Implementing the todoitem flag"
	478	```
	479	```bash
	480	git push
142de4	481	```
D	482
3ee499	483	3. Open our local todolist app (http://localhost:8080/#/todo). If we try to use our important flag, we should see it's still not behaving as expected; this is because we're not updating the state of the app in response to the click event.
D	484
	485	3. We need to implement the `actions` and `mutations` for our feature. Let's start with the tests. Open the `tests/unit/javascript/actions.spec.js` and navigate to the bottom of the file. Our action should should commit the `MARK_TODO_IMPORTANT` to the mutations. Scroll to the end of the test file and implement the skeleton test by adding `expect(commit.firstCall.args[0]).toBe("MARK_TODO_IMPORTANT");` as the assertion.
142de4	486	```javascript
D	487	it("should call MARK_TODO_IMPORTANT", done => {
	488	const commit = sinon.spy();
	489	state.todos = todos;
	490	actions.updateTodo({ commit, state }, { id: 1, important: true }).then(() => {
	491	// TODO - test goes here!
	492	expect(commit.firstCall.args[0]).toBe("MARK_TODO_IMPORTANT");
	493	done();
	494	});
	495	});
	496	```
	497
7d4ccd	498	3. We should now have more failing tests, let's fix this by adding the call from our action to the mutation method. Open the `src/store/actions.js` file and scroll to the bottom to the `updateTodo()` method. Complete the if block by adding `commit("MARK_TODO_IMPORTANT", i);` as shown below.
142de4	499	```javascript
D	500	updateTodo({ commit, state }, { id, important }) {
	501	let i = state.todos.findIndex(todo => todo._id === id);
	502	if (important) {
9f3a7a	503	// TODO - add commit important here!
142de4	504	commit("MARK_TODO_IMPORTANT", i);
D	505	} else {
	506	commit("MARK_TODO_COMPLETED", i);
	507	}
	508	```
	509
853f0c	510	3. Finally, let's implement the `mutation` for our feature. Again, starting with the tests... Open the `tests/unit/javascript/mutations.spec.js` to find our skeleton tests at the bottom of the file. Our mutation method is responsible for toggling the todo's `important` property between `true` and `false`. Let's implement the tests for this functionality by setting important to be true and calling the method expecting the inverse. Then let's set it to false and call the method expecting the inverse. Add the expectations below the `// TODO - test goes here!` comment as done previously.
142de4	511	```javascript
D	512	it("it should MARK_TODO_IMPORTANT as false", () => {
	513	state.todos = importantTodos;
	514	// TODO - test goes here!
	515	mutations.MARK_TODO_IMPORTANT(state, 0);
	516	expect(state.todos[0].important).toBe(false);
	517	});
	518
	519	it("it should MARK_TODO_IMPORTANT as true", () => {
	520	state.todos = importantTodos;
	521	// TODO - test goes here!
	522	state.todos[0].important = false;
	523	mutations.MARK_TODO_IMPORTANT(state, 0);
	524	expect(state.todos[0].important).toBe(true);
	525	});
	526	```
	527
e1ba4f	528	3. With our tests running and failing, let's implement the feature to their spec. Open the `src/store/mutations.js` and add another function called `MARK_TODO_IMPORTANT` below the `MARK_TODO_COMPLETED` to toggle `todo.important` between true and false. NOTE - add a `,` at the end of the `MARK_TODO_COMPLETED(){}` function call.
142de4	529	```javascript
D	530	MARK_TODO_IMPORTANT(state, index) {
	531	console.log("INFO - MARK_TODO_IMPORTANT");
	532	state.todos[index].important = !state.todos[index].important;
	533	}
	534	```
3ee499	535	![mark-todo-important](../images/exercise3/mark-todo-important.png)
142de4	536
e1ba4f	537	3. All our tests should now be passing. On the watch tab where they are running, hit `a` to re-run all tests and update any snapshots with `u` if needed.
142de4	538
D	539	3. With all our tests now passing, let's commit our code. On the terminal, run
	540	```bash
58480f	541	git add .
D	542	```
	543	```bash
	544	git commit -m "Implementing the store and actions"
	545	```
	546	```bash
	547	git push
142de4	548	```
D	549
5965fd	550	3. Before running a build in Jenkins, let's add our tests and code to the develop branch. Ask your neighbour to review your code changes and if they approve; merge them to Develop! (If you're feeling adventurous - raise a PR through GitLab and have someone on your desk peer review it!)
142de4	551	<p class="tip">
D	552	NOTE - At this point in a residency we would peer review the code before pushing it to develop or master branch!
	553	</p>
	554	```bash
58480f	555	git checkout develop
D	556	```
	557	```bash
	558	git merge feature/important-flag
	559	```
	560	```bash
	561	git push --all
142de4	562	```
D	563
3ee499	564	3. Run a build in Jenkins. If all things were successful; our application should be deployed as expected! Validate the flag is working as expected.
D	565	![todolist-important](../images/exercise3/todolist-important.png)
d1565e	566
752f2a	567	#### 2c - Create todolist e2e tests
d1565e	568
cf760d	569	> Using [Nightwatch.js](http://nightwatchjs.org/) We will write a reasonably simple e2e test to test the functionality of the feature we just implemented.
d6eb80	570
T	571	3. Firstly we need to create an e2e spec test file in the correct place.
	572
	573	```bash
	574	touch tests/e2e/specs/importantFlag.js
	575	```
	576
	577	3. Open this new file in your code editor and set out the initial blank template for an e2e test as below:
	578	![if-e2e-step1](../images/exercise3/if-e2e-step1.png)
	579
	580	3. Now get the test to access the todos page and wait for it to load. The url can be taken from `process.env.VUE_DEV_SERVER_URL`
	581	![if-e2e-step2](../images/exercise3/if-e2e-step2.png)
	582
	583	3. Now click the clear all button and then enter a value in the textbox to create a new item. We clear all first to ensure we start with a fresh list. We now do our first assertion: that a 'important flag' exists (the button to set important), and also that a red flag does not exist. You will quickly find there is no way to reference the clear all button. We will therefore have to go to `src/components/XofYItems.vue` and add `id="clear-all"` to the clear all button.
	584	![if-e2e-step3](../images/exercise3/if-e2e-step3.png)
	585	![if-e2e-step3a](../images/exercise3/if-e2e-step3a.png)
	586
	587	3. We should now get nightwatch to click the flag and check whether the flag has turned red.
	588	![if-e2e-step4](../images/exercise3/if-e2e-step4.png)
	589
	590	3. At this point we should have a working e2e test. We can run this by using `npm run e2e`. When satisfied we can push up these changes.
	591
	592	```bash
	593	git add .
	594	```
	595
	596	```bash
	597	git commit -m "Implementing e2e tests"
	598	```
	599
	600	```bash
	601	git push
	602	```
5a16fd	603
01245c	604	---
5a16fd	605
D	606	## Extension Tasks
01245c	607
5a16fd	608	> _Ideas for go-getters. Advanced topic for doers to get on with if they finish early. These will usually not have a solution and are provided for additional scope._
D	609
cad21a	610	* Add Config maps to inject DB creds to the app
D	611	* Create a blue/green deploy based on the success of running e2e tests against either blue or green and flopping load over to new endpoint when successful.
	612	Advanced
	613	* Add Auth0 support to your FE app.
5a16fd	614
D	615	## Additional Reading
01245c	616
5a16fd	617	> List of links or other reading that might be of use / reference for the exercise
D	618
	619	## Slide links
01245c	620
4f0295	621	- [Intro](https://docs.google.com/presentation/d/18W0GoBTwRGpgbOyHf2ZnL_OIWU_DvsoR14H0_t5jisA)
RH	622	- [Wrap-up](https://docs.google.com/presentation/d/1uIYHC57POSaVD6XNZGhdetABiSnlP1TztYTgglMP-DA)
5e7a31	623	- [All Material](https://drive.google.com/drive/folders/1xVaQukmwwmyJSDN0zOkghZX7yb-0freT)