Install Docker Desktop if you don't have it installed:
- [Docker Desktop for Mac](https://docs.docker.com/docker-for-mac/install/)
- [Docker Desktop for Windows](https://docs.docker.com/docker-for-windows/install/)
Once installed, you should see `Docker Desktop is running` message with the green light next to it indicating that everything is working as expected.
Note, that if you install docker through other methods such as homebrew, for example, your steps to set it up will be different. The commands listed in steps below may also vary.
This section explains how e2e tests are working behind the scenes. These are not instructions on how to build environment for running e2e tests and run them. If you are looking for instructions on how to run e2e tests, jump to [Running tests](#running-tests).
We recommend using Docker for running tests locally in order for the test environment to match the setup on Travis CI (where Docker is also used for running tests). [An official WordPress Docker image](https://github.com/docker-library/docs/blob/master/wordpress/README.md) is used to build the site. Once the site using the WP Docker image is built, the current WooCommerce dev branch is being copied to the `plugins` folder of that newly built test site. No WooCommerce Docker image is being built or needed.
If you need to modify the port for your local test environment (eg. port is already in use), copy `tests/e2e/env/config/default.json` to `tests/e2e/config/default.json` and edit that copy. Only edit this file while your test container is `down`.
[Jest](https://jestjs.io/) is being used to run e2e tests. By default, jest runs tests ordered by the time it takes to run the test (the test that takes longer to run will be run first, the test that takes less time to run will run last). Jest sequencer introduces tools that can be used to specify the order in which the tests are being run. In our case, they are being run in alphabetical order of the directories where tests are located. This way, tests in the new directory `activate-and-setup` will run first.
Setup Wizard e2e test (located in `activate-and-setup` directory) will run before all other tests. This will allow making sure that WooCommerce is activated on the site and for the setup wizard to be completed on a brand new install of WooCommerce.
By default, `Puppeteer` downloads the `Chromium` package every time you run `npm install` or `npm update`. To disable that download add the following to your `.bash_profile` or `.zshrc` (whichever you use):
```shell script
export PUPPETEER_SKIP_CHROMIUM_DOWNLOAD=true
```
Puppeteer will still automatically download Chromium when needed.
- Run `npm run docker:up` - it will build the test site using Docker.
- Run `docker ps` - to confirm that the Docker containers were built and running. You should see the log that looks similar to below indicating that everything had been built as expected:
Note that by default, Docker will download the latest images available for WordPress, PHP and MariaDB. In the example above, you can see that WordPress 5.5.1 and MariaDB 10.5.5 were used.
See [How to run tests using custom WordPress, PHP and MariaDB versions](#how-to-run-tests-using-custom-wordpress,-php-and-mariadb-versions) if you'd like to use different versions.
If everything went well, you should be able to access the site. If you changed the port to something other than `8084` as per [Test Variables](#test-variables) section, use the appropriate port to access your site.
Tests are run headless by default. However, sometimes it's useful to observe the browser while running tests. To do so, you can run tests in a non-headless (dev) mode:
The dev mode also enables SlowMo mode. SlowMo slows down Puppeteer’s operations so we can better see what is happening in the browser.
By default, SlowMo mode is set to slow down running of tests by 50 milliseconds. If you'd like to override it and have the tests run faster or slower in the `-dev` mode, pass `PUPPETEER_SLOWMO` variable when running tests as shown below:
```
PUPPETEER_SLOWMO=10 npm run test:e2e-dev
```
The faster you want the tests to run, the lower the value should be of `PUPPETEER_SLOWMO` should be.
Tests are run headless by default. While writing tests it may be useful to have the debugger loaded while running a test in non-headless mode. To run tests in debug mode:
```bash
npm run test:e2e-debug
```
When all tests have been completed the debugger is left active. Control doesn't return to the command line until the debugger is closed. Otherwise, debug mode functions the same as non-headless mode.
To skip the tests, use `.only` in the relevant test entry to specify the tests that you do want to run.
For example, in order to skip Setup Wizard tests, add `.only` to the login and activation tests as follows in the `setup-wizard.test.js`:
```
it.only( 'Can login', async () => {}
```
```
it.only( 'Can make sure WooCommerce is activated. If not, activate it', async () => {}
```
As a result, when you run `setup-wizard.test.js`, only the login and activate tests will run. The rest will be skipped. You should see the following in the terminal:
- [Puppeteer](https://github.com/GoogleChrome/puppeteer) – a Node library which provides a high-level API to control Chrome or Chromium over the DevTools Protocol
- [jest-puppeteer](https://github.com/smooth-code/jest-puppeteer) – provides all required configuration to run tests using Puppeteer
- [expect-puppeteer](https://github.com/smooth-code/jest-puppeteer/tree/master/packages/expect-puppeteer) – assertion library for Puppeteer
-`@wordpress/e2e-test-utils` - End-To-End (E2E) test utils for WordPress. You can find the full list of utils [here](https://github.com/WordPress/gutenberg/tree/master/packages/e2e-test-utils);
-`@automattic/puppeteer-utils` - Utilities and configuration for running puppeteer against WordPress. See details in the [package's repository](https://github.com/Automattic/puppeteer-utils).
It is a good practice to start working on the test by identifying what needs to be tested on the higher and lower levels. For example, if you are writing a test to verify that merchant can create virtual product, the overview of the test will be as follows:
- Merchant can create virtual product
- Merchant can log in
- Merchant can create virtual product
- Merchant can verify that virtual product was created
Once you identify the structure of the test, you can move on to writing it.
### Writing the test
The structure of the test serves as a skeleton for the test itself. You can turn it into a test by using `describe()` and `it()` methods of Jest:
- [`describe()`](https://jestjs.io/docs/en/api#describename-fn) - creates a block that groups together several related tests;
- [`it()`](https://jestjs.io/docs/en/api#testname-fn-timeout) - actual method that runs the test.
Based on our example, the test skeleton would look as follows:
```
describe( 'Merchant can create virtual product', () => {
it( 'merchant can log in', async () => {
} );
it( 'merchant can create virtual product', async () => {
} );
it( 'merchant can verify that virtual product was created', async () => {
} );
} );
```
Next, you can start filling up each section with relevant functions (test building blocks). Note, that we have the `@woocommerce/e2e-utils` package where many reusable helper functions can be found for writing tests. For example, `flows.js` of `@woocommerce/e2e-utils` package contains `StoreOwnerFlow` object that has `login` method. As a result, in the test it can be used as `await StoreOwnerFlow.login();` so the first `it()` section of the test will become:
```
it( 'merchant can log in', async () => {
await StoreOwnerFlow.login();
} );
```
Moving to the next section where we need to actually create a product. You will find that we have a reusable function such as `createSimpleProduct()` in the `components.js` of `@woocommerce/e2e-utils` package. Note that this function should not be used for this test because the way simple product is being created in this function is by using WooCommerce REST API. Because this is not how the merchant would typically create a virtual product, we would need to test it by writing actual steps for creating a product in the test.
`createSimpleProduct()` should be used in tests where you need to test something else than creating a simple product. In other words, this function exists in order to quickly fill the site with test data required for running tests. For example, if you want to write a test that will verify that shopper can place a product to the cart on the site, you can use `createSimpleProduct()` to create a product to test the cart.
### Best practices
- It is best to keep the tests inside `describe()` block granular as it helps to debug the test if it fails. When the test is done running, you will see the result along with the breakdown of how each of the test sections performed. If one of the tests within `describe()` block fails, it will be shown as follows:
In the example above, you can see that `allows customer to see downloads` part of the test failed and can start looking at it right away. Without steps the test goes through being detailed, it is more difficult to debug it.
