RedHatTraining/rht-labs-docs.git

acammies

2018-04-17 536726e9ee43178fc0728674389511ea87dfd491

commit \| author \| age
43f2f2	1	# Exercise Title
D	2
5285f8	3	> The purpose of this lab is to develop and validate a new feature using TDD; and to promote the assured feature through the pipeline.
f6d2bd	4
62a054	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
f6d2bd	9	---
43f2f2	10
D	11	## Learning Outcomes
f6d2bd	12
43f2f2	13	As a learner you will be able to
f6d2bd	14
5285f8	15	* Understand the why behind TDD
D	16	* Implement a feature using TDD for frontend and backend
	17	* Write end to end tests for the feature and run them in CI
43f2f2	18
D	19	## Tools and Frameworks
f6d2bd	20
43f2f2	21	> Name of tool - short description and link to docs or website
D	22
5285f8	23	1. [Jest](https://facebook.github.io/jest/) - Zero configuration testing platform
D	24	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.
	25	1. [Vue Test Utils](https://vue-test-utils.vuejs.org/en/) - Vue Test Utils is the official unit testing utility library for Vue.js.
	26	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.
	27	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.
	28	1. [Sinon](http://sinonjs.org/) - Standalone test spies, stubs and mocks for JavaScript.
	29	Works with any unit testing framework.
43f2f2	30
D	31	## Big Picture
f6d2bd	32
43f2f2	33	This exercise begins cluster containing blah blah
D	34
f6d2bd	35	---
43f2f2	36
D	37	## 10,000 Ft View
	38
5285f8	39	> The goal of this exercise is to add a new component to the application using TDD to create and validate it's behaviour. The User story we have been given is as follows:
43f2f2	40
5285f8	41	As a doer I want to mark todos as important so that I can keep track of and complete high prirority todos first
f6d2bd	42
5285f8	43	_Acceptance Criteria_
D	44	- [ ] should be doable with a single click
	45	- [ ] should add a red flag against the todo when marked important
	46	- [ ] should remove the red colour flag on the flag when important removed
	47	- [ ] should not affect existing todos
	48
	49	_On page load:_
	50	- [ ] should display existing todos that are not marked important
	51	- [ ] should display existing todos that are marked important with an red flag
43f2f2	52
D	53	## Step by Step Instructions
91cc51	54	> This is a fairly structured guide with references to exact filenames and sections of text to be added.
43f2f2	55
03b14c	56	### Part 0 - Introduction to TDD.
A	57	> _We'll show you what TDD is, and introduce our existing tests within our code._
	58
	59	#### Part 0a - What is TDD?
	60	> _Here is a brief introduction of TDD and why we use it._
	61
7e6765	62	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.
03b14c	63
7e6765	64	The TDD can be illustrated with the following diagram;
RH	65	![TDD-diagram](../images/exercise3/TDD-lifecycle.jpg)
03b14c	66
A	67	#### Part 0b - Introduction to our tests.
	68	> _In this part we will get familiar with the layout of our tests_
	69
f56999	70	2. We'll go into detail on how to write tests further on. To run your test suites run the following in the root of your `todolist-fe` or `todolist-api` repositories.
A	71	```bash
	72	$ npm run test
	73	```
	74
	75	2. This command will run all `*spec.js` files. Our test files are stored in the following places:
03b14c	76
b6ebf8	77	- There are 2 Api test files: `todolist-api/server/api/todo/todo.spec.js` & `todolist-api/server/mocks/mock-routes.spec.js`
A	78
	79	- There are 12 Frontend test files stored in these directories: `todolist-fe/tests/unit/vue-components/` & `todolist-fe/tests/unit/javascript/`
f56999	80
536726	81	2. Explanation of Mocha and js test syntax through Bananalogy:
f56999	82	![todoitem-fail-test](../images/exercise3/bdd-bananas.png)
A	83
536726	84	* `describe` is used to group tests together into a collection about a particular
A	85
	86	2. Visit [mochajs.org](https://mochajs.org/) for more in-depth documentation.
	87
	88
	89
	90	* `describe` is used to group tests together into a collection asserting some feature; for example the get all todos api.
	91	* `it` is an individual test statement and should contain an `expect` or a `should` statement asserting behaviour of the API under test.
	92
	93
43f2f2	94
034b0f	95
f6d2bd	96	### Part 1 - Tests in our Pipeline
D	97
bc2216	98	> _In this exercise we will improve the pipeline created already by adding some unit tests for the frontend & backend along with some end to end tests (e2e) to validate the full solution_
43f2f2	99
bc2216	100	#### Part 1a - Unit tests
bc975e	101	> In this exercise we will execute our test for the frontend and backend locally. Once verified we will add them to Jenkins.
bc2216	102
bc975e	103	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`.
91cc51	104	```bash
A	105	$ cd todolist-fe
	106	$ npm run test
	107	```
	108	<p class="tip" >
60bca4	109	`test` is an alias used that runs `vue-cli-service test` from the scripts object in `package.json`
91cc51	110	</p>
A	111	![new-gitlab-proj](../images/exercise3/screenshot-scripts.png)
bc2216	112
91cc51	113	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.
A	114	![new-gitlab-proj](../images/exercise3/test-run-locally.png)
	115
	116	2. Repeat the same process for `todolist-api` and verify that all the tests run.
	117	```bash
	118	$ cd todolist-api
	119	$ npm run test
	120	```
6e5072	121
91cc51	122	2. Navigate to your instance of jenkins at `https://jenkins-<YOUR_NAME>-ci-cd.apps.s8.core.rht-labs.com/`.
A	123	Click on `dev-todolist-fe-build` and then click the `configure` button on the left-hand side.
	124	![new-gitlab-proj](../images/exercise3/jenkins-configure-job.png)
	125
	126	2. Scroll to the `Build` part of the configuration page and add `scl enable rh-nodejs8 'npm run test'` below `scl enable rh-nodejs8 'npm install'`. Click `save` or `apply` at the bottom to save the changes.
	127	![new-gitlab-proj](../images/exercise3/jenkins-build-step.png)
	128
60bca4	129	2. Scroll to the `Post-build Actions` section and click `Add post-build action`. Select `Publish xUnit test result report`.
A	130	![new-gitlab-proj](../images/exercise3/xunit-action.png)
6e5072	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:
	133	![new-gitlab-proj](../images/exercise3/post-build-actions.png)
	134
f56999	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.
6e5072	136
A	137	2. We're now going to deliberately fail a test to ensure that `bake` and `deploy` jobs aren't triggered if any tests fail. Go to `ListOfTodos.spec.js` in `/tests/unit/vue-components` and head to `line 38`. Add `not.` before `toHaveBeenCalled()`.
	138	![new-gitlab-proj](../images/exercise3/change-test-to-fail.png)
	139
f56999	140	2. Push this to Gitlab and run the build job.
6e5072	141	```bash
A	142	$ git add .
	143	$ git commit -m "Deliberately failed test to test the pipeline stops me deploying broken code"
	144	$ git push
	145	```
	146
	147	2. Rerun the `dev-todolist-fe-build` job. It should have failed and not run any other builds.
	148	![new-gitlab-proj](../images/exercise3/jenkins-with-failing-build.png)
	149
2717b2	150	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`.
A	151
	152	2. We're now going to do the same for the api. Head to the `configure` panel of the `dev-todolist-api-build` job.
	153
	154	2. Add `scl enable rh-nodejs8 'npm run test:ci'` above `npm run build:ci`.
	155	![new-gitlab-proj](../images/exercise3/api-build-step.png)
	156
4f979b	157	2. Scroll to the `Post-build Actions` section and click `Add post-build action`. Select `Publish xUnit test result report`.
2717b2	158
A	159	2. Click the `Add` button under `Publish xUnit test result report` and select `JUnit`. In the pattern field enter `reports/server/mocha/test-results.xml`. In the `Failed Tests Thresholds` input box enter 0 under `Red Ball Total`. It should look a little something like this:
	160	![new-gitlab-proj](../images/exercise3/api-post-build.png)
	161
	162	2. We're now going to deliberately fail a test again to ensure that `bake` and `deploy` jobs aren't triggered if any tests fail. Go to `todo.spec.js` in `/server/api/todo` and head to `line 35`. Replace `false` with `true`.
	163	![new-gitlab-proj](../images/exercise3/api-fail-build.png)
	164
f56999	165	2. Push this to Gitlab and run the build job.
2717b2	166	```bash
A	167	$ git add .
	168	$ git commit -m "Deliberately failed test to test the pipeline stops me deploying broken code"
	169	$ git push
	170	```
	171
f56999	172	2. If successful this will fail the build and not run the `bake` or `deploy` jobs.
A	173
	174	<p class="tip">
	175	NOTE - Don't forget to undo the changes that you made to your tests!
	176	</p>
2717b2	177
bc2216	178	#### Part 1b - End to End tests (e2e)
4f979b	179	> TODO - this section is not complete
bc2216	180
f6d2bd	181	2. Add new part to the dev pipeline (`dev-todolist-fe-e2e`)
bc2216	182
4f979b	183	2. Add e2e tests and reporting to Jenkins
bc2216	184
5285f8	185	### Part 2 - TodoList new feature
bc2216	186	> _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	187
5285f8	188	As a doer I want to mark todos as important so that I can keep track of and complete high prirority todos first
bc2216	189
5285f8	190	_Acceptance Criteria_
D	191	- [ ] should be doable with a single click
	192	- [ ] should add a red flag against the todo when marked important
	193	- [ ] should remove the red colour flag on the flag when important removed
	194	- [ ] should not affect existing todos
bc2216	195
5285f8	196	_On page load:_
D	197	- [ ] should display existing todos that are not marked important
	198	- [ ] should display existing todos that are marked important with an red flag
bc2216	199
f6d2bd	200	#### Part 1a - Create todolist-api tests
5285f8	201	> 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.
f6d2bd	202
D	203	3. Create a new branch in your `todolist-api` app for our feature and push it to the remote
bc2216	204	```bash
D	205	$ git checkout -b feature/important-flag
	206	$ git push -u origin feature/important-flag
43f2f2	207	```
D	208
f6d2bd	209	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	210	```javascript
	211	describe("GET /api/todos", function() {
	212	it("should respond with JSON array", function(done) {
	213	request(app)
	214	.get("/api/todos")
	215	.expect(200)
	216	.expect("Content-Type", /json/)
	217	.end(function(err, res) {
	218	if (err) return done(err);
	219	// Test goes here
	220	res.body.should.be.instanceof(Array);
	221	done();
	222	});
5285f8	223	});
f6d2bd	224	});
D	225	```
	226	where:
5285f8	227	_ `describe` is used to group tests together into a collection asserting some feature; for example the get all todos api.
D	228	_ `it` is an individual test statement and should contain an `expect` or a `should` statement asserting behaviour of the API under test.
	229	_ `request` is a library for making http calls to the api.
	230	_ `.expect(200)` asserts the HTTP Return Code
	231	_ `res.body.should.be.instanceof(Array);` is the actual test call
	232	_ `done();` tells the test runner that `mocha` has finished execution. This is needed as the http calls are asynchronous.
43f2f2	233
5285f8	234	3. With this knowledge; let's implement our test for the `important` flag. We expect the fronted 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 test which should be at the bottom ![todo-api-tests](../images/exercise3/todo-api-tests.png).
f6d2bd	235
5285f8	236	3. Before writing our test; let's first make sure all the existing tests are passing.
D	237	```bash
f6d2bd	238	$ npm run test
D	239	```
	240
5285f8	241	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. A PUT request responds in our API with the data that it just updated, so provided that MongoDB accepted the change, it will respond with an object that has the `important` property on it. To write our test; edit the `it("should ....", function(done) {` by completing the following:
f6d2bd	242	* Edit the `it("should ...")` to describe the imporant flag we're testing
D	243	* Edit the `.send()` to include `important: true` property
	244	* Add a new test assertion to check that `res.body.important` is `true` below the `// YOUR TEST GO HERE` line.
	245	```javascript
5285f8	246	it("should mark todo as important and persist it", function(done) {
f6d2bd	247	request(app)
D	248	.put("/api/todos/" + todoId)
5285f8	249	.send({
D	250	title: "LOVE endpoint/server side testing!",
	251	completed: true,
	252	important: true
	253	})
f6d2bd	254	.expect(200)
D	255	.expect("Content-Type", /json/)
	256	.end(function(err, res) {
5285f8	257	if (err) return done(err);
D	258	res.body.should.have.property("_id");
	259	res.body.title.should.equal("LOVE endpoint/server side testing!");
	260	// YOUR TEST GO HERE
	261	res.body.important.should.equal(true);
	262	done();
f6d2bd	263	});
5285f8	264	});
f6d2bd	265	```
D	266
5285f8	267	3. Run your test. It should fail.
D	268	```bash
f6d2bd	269	$ npm run test
D	270	```
	271	![fail-mocha](../images/exercise3/fail-mocha.png)
	272
5285f8	273	3. With our test now failing; let's implement the feature. This is quite a simple change; all we need to do it update the `server/api/todo/todo.model.js` to allow an additional property on the schema called `important` of type Boolean.
f6d2bd	274	```javascript
D	275	const TodoSchema = new Schema({
5285f8	276	title: String,
D	277	completed: Boolean,
	278	important: Boolean
f6d2bd	279	});
D	280	```
	281
5285f8	282	3. With your changes to the Database schema updated; re-run your tests.
D	283	```bash
f6d2bd	284	$ npm run test
D	285	```
	286
5285f8	287	3. Commit your code to the `feature/important-flag` branch and then merge onto the `develop` branch as follows
f6d2bd	288	<p class="tip">
D	289	NOTE - At this point in a residency we would peer review the code before pushing it to develop or master branch!
	290	</p>
5285f8	291	```bash
f6d2bd	292	$ git add .
D	293	$ git commit -m "ADD backend schema updates"
	294	$ git checkout develop
	295	$ git merge feature/important-flag
	296	$ git push --all
	297	```
	298
	299	#### Part 1b - Create todolist-fe tests
5285f8	300	> 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 fronted 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.
f6d2bd	301
5285f8	302	Our TodoList App uses `vuex` to manage the state of the apps' 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.
f6d2bd	303
5285f8	304	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 it's own way of updating the store. It is bad practice to call the store directly.
D	305
	306	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 apps local store for rendering in the view.
	307
	308	For example; when marking a todo as done in the UI, the following flow occurs
	309	* The `TodoItem.vue` calls the `markTodoDone()` function which dispatches an event to the store.
	310	* This calls the `updateTodo()` function in the `actions.js` file
	311	* The action will update the backend db (calling our `todolist-api`) with our updated todo object.
	312	* The action will commit the change to the store by calling the mutation method `MARK_TODO_COMPLETED`
	313	* The `MARK_TODO_COMPLETED` will directly access the store object and update it with the new state value
	314	* The `ListOfTodos.vue` component is watching the store for changes and when something gets updated it re-renders the `TodoItem.vue`.
	315
	316	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
f6d2bd	317	```bash
D	318	$ git checkout -b feature/important-flag
	319	$ git push -u origin feature/important-flag
	320	```
bc2216	321
5285f8	322	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. All the tests should be passing when we begin
D	323	```bash
	324	$ npm run test -- --watch
	325	```
	326
bc581a	327	3. There are three places we will add new tests to validate our function behaves as expected against the acceptance criteria from 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 lab. Find the describe block for our important flag tests. It is setup already with a `beforeEach()` hook for test setup.
5285f8	328	![important-flag-before](../images/exercise3/important-flag-before.png)
D	329
	330	3. Each of our test cases has it's 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.
	331	![todoitem-skeleton-tests](../images/exercise3/todoitem-skeleton-tests.png)
	332
	333	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.
	334	```javascript
	335	it("should render a button with important flag", () => {
	336	const wrapper = mount(TodoItem, {
	337	propsData: { todoItem: importantTodo }
	338	});
	339	// TODO - test goes here!
	340	expect(wrapper.find(".important-flag").exists()).toBe(true);
	341	});
	342	```
	343
	344	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!
	345	![todoitem-fail-test](../images/exercise3/todoitem-fail-test.png)
	346
	347	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 imporant is true and not when false.
	348	```javascript
	349	it("should set the colour to red when true", () => {
	350	const wrapper = mount(TodoItem, {
	351	propsData: { todoItem: importantTodo }
	352	});
	353	// TODO - test goes here!
	354	expect(wrapper.find(".red-flag").exists()).toBe(true);
	355	});
	356	it("should set the colour to not red when false", () => {
	357	importantTodo.important = false;
	358	const wrapper = mount(TodoItem, {
	359	propsData: { todoItem: importantTodo }
	360	});
	361	// TODO - test goes here!
	362	expect(wrapper.find(".red-flag").exists()).toBe(false);
	363	});
	364	```
	365
bc581a	366	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 makImportant when clicked", () ` test by first simulating the click of our important-flag and asserting the function `markImportant()` to write is executed.
5285f8	367	```javascript
D	368	it("call makImportant when clicked", () => {
	369	const wrapper = mount(TodoItem, {
	370	methods,
	371	propsData: { todoItem: importantTodo }
	372	});
	373	// TODO - test goes here!
	374	const input = wrapper.find(".important-flag");
	375	input.trigger("click");
	376	expect(methods.markImportant).toHaveBeenCalled();
	377	});
	378	```
	379
	380	3. With our tests written for the feature's UI component, let's implement our code to pass the tests. Open up the `src/components/TodoItem.vue`. Each vue file is broken down into 3 sections
	381	* The `<template></template>` contains the HTML of our component. This could include references to other Components also
	382	* 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`
	383	* The `<style></style>` contains the encapsulated CSS of our component
	384	Underneath the `</md-list-item>` tag, let's add a new md-button. Add a `.important-flag` class on the `md-button` and put the svg of the flag provided inside it.
	385	```html
	386	</md-list-item>
	387	<!-- TODO - SVG for use in Lab3 -->
	388	<md-button class="important-flag">
	389	<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>
	390	</md-button>
	391	```
	392
	393	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.
	394	```html
	395	<md-button class="important-flag">
	396	<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>
	397	</md-button>
	398	```
	399
	400	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 and additional property to this method call `imporant`
	401	```javascript
	402	markImportant() {
	403	// TODO - FILL THIS OUT IN THE LAB EXERCISE
	404	this.$store.dispatch("updateTodo", {id: this.todoItem._id, important: true});
	405	console.info("INFO - Mark todo as important ", this.todoItem.important);
	406	},
	407	```
	408
	409	3. Finally - 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
	410	```html
	411	<!-- TODO - SVG for use in Lab3 -->
	412	<md-button class="important-flag" @click="markImportant()">
	413	<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>
	414	</md-button>
	415	```
	416
	417	3. The previously failing tests should have started to pass now. With this work done, let's commit our code. On the terminal, run
	418	```bash
	419	$ git add .
	420	$ git commit -m "Implementing the todoitem flag"
	421	$ git push
	422	```
	423
bc581a	424	3. 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. 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.
5285f8	425	```javascript
D	426	it("should call MARK_TODO_IMPORTANT", done => {
	427	const commit = sinon.spy();
	428	state.todos = todos;
	429	actions.updateTodo({ commit, state }, { id: 1, important: true }).then(() => {
	430	// TODO - test goes here!
	431	expect(commit.firstCall.args[0]).toBe("MARK_TODO_IMPORTANT");
	432	done();
	433	});
	434	});
	435	```
	436
bc581a	437	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.
5285f8	438	```javascript
D	439	updateTodo({ commit, state }, { id, important }) {
	440	let i = state.todos.findIndex(todo => todo._id === id);
	441	if (important) {
	442	// TODO - add commit imporant here!
	443	commit("MARK_TODO_IMPORTANT", i);
	444	} else {
	445	commit("MARK_TODO_COMPLETED", i);
	446	}
	447	```
	448
	449	3. Finally, let's implement the `mutation` for our feature. Again, starting with the tests..... Open the `tests/unit/javascript/mutations.spec.js`. Our mutation method is responsible to toggling the todo's `important` property between true and
	450	false. Let's implement the tests for this functionality by setting imporant to be true and calling the method expecting the inverse and setting it to false and calling the method expecting the inverse.
	451	```javascript
	452	it("it should MARK_TODO_IMPORTANT as false", () => {
	453	state.todos = importantTodos;
	454	// TODO - test goes here!
	455	mutations.MARK_TODO_IMPORTANT(state, 0);
	456	expect(state.todos[0].important).toBe(false);
	457	});
	458
	459	it("it should MARK_TODO_IMPORTANT as true", () => {
	460	state.todos = importantTodos;
	461	// TODO - test goes here!
	462	state.todos[0].important = false;
	463	mutations.MARK_TODO_IMPORTANT(state, 0);
	464	expect(state.todos[0].important).toBe(true);
	465	});
	466	```
	467
	468	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.
	469	```javascript
	470	MARK_TODO_IMPORTANT(state, index) {
	471	console.log("INFO - MARK_TODO_IMPORTANT");
	472	state.todos[index].important = !state.todos[index].important;
	473	}
	474	```
	475
	476	3. All our tests should now be passing. On the watch tab where they are running, hit `u` to re-run all tests and update any snapshots.
	477
	478	3. With all our tests now passing, let's commit our code. On the terminal, run
	479	```bash
	480	$ git add .
	481	$ git commit -m "Implementing the store and actions"
	482	$ git push
	483	```
	484
	485	3. Before running a build in Jenkins, let's add our tests and code to the develop branch
	486	<p class="tip">
	487	NOTE - At this point in a residency we would peer review the code before pushing it to develop or master branch!
	488	</p>
	489	```bash
	490	$ git checkout develop
	491	$ git merge feature/important-flag
	492	$ git push --all
	493	```
	494
	495	3. Run a build in Jenkins. We should see the test trend increase as we've added more tests. Validate the flag is working as expected.
bc2216	496
D	497	#### Part 1c - Create todolist e2e tests
	498
5285f8	499	3. TODO !!
43f2f2	500
f6d2bd	501	---
43f2f2	502
D	503	## Extension Tasks
f6d2bd	504
43f2f2	505	> _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	506
f6d2bd	507	* Add Auth to your application
D	508	* Do some other stuff
43f2f2	509
D	510	## Additional Reading
f6d2bd	511
43f2f2	512	> List of links or other reading that might be of use / reference for the exercise
D	513
	514	## Slide links
f6d2bd	515
D	516	> link back to the deck for the supporting material