docs(e2e-webdriverio): add WebdriverIO docs

docs/.vuepress/config.js

@@ -184,7 +184,8 @@ module.exports = {
               '/core-plugins/unit-jest.md',
               '/core-plugins/unit-mocha.md',
               '/core-plugins/e2e-cypress.md',
-              '/core-plugins/e2e-nightwatch.md'
+              '/core-plugins/e2e-nightwatch.md',
+              '/core-plugins/e2e-webdriverio.md'
             ]
           }],
 

docs/config/README.md

@@ -446,3 +446,7 @@ See [@vue/cli-plugin-e2e-cypress](https://github.com/vuejs/vue-cli/tree/dev/pack
 ### Nightwatch
 
 See [@vue/cli-plugin-e2e-nightwatch](https://github.com/vuejs/vue-cli/tree/dev/packages/%40vue/cli-plugin-e2e-nightwatch) for more details.
+
+### WebdriverIO
+
+See [@vue/cli-plugin-e2e-webdriverio](https://github.com/vuejs/vue-cli/tree/dev/packages/%40vue/cli-plugin-e2e-webdriverio) for more details.

docs/core-plugins/README.md

@@ -12,3 +12,4 @@ This section contains documentation for core Vue CLI plugins:
 - [Mocha](unit-mocha.md)
 - [Cypress](e2e-cypress.md)
 - [Nightwatch](e2e-nightwatch.md)
+- [WebdriverIO](e2e-webdriverio.md)

docs/core-plugins/e2e-webdriverio.md

@@ -0,0 +1,64 @@
+# @vue/cli-plugin-e2e-nightwatch
+
+> e2e-webdriverio plugin for vue-cli
+
+## Injected Commands
+
+- **`vue-cli-service test:e2e`**
+
+  Run end-to-end tests with [WebdriverIO](https://webdriver.io/).
+
+  Options:
+
+  ```
+  --url                 run the tests against given url instead of auto-starting dev server
+  --headless            use chrome or firefox in headless mode
+  --remote              run e2e tests on a cloud provider
+  ```
+
+  Additionally, all [WebdriverIO CLI options](https://webdriver.io/docs/clioptions.html) are also supported.
+  E.g.: `--spec`, `--watch` etc.
+
+
+## Project Structure
+
+The following structure will be generated when installing this plugin. It includes a spec file a page object definition for the Vue.js app as example.
+
+```
+tests/e2e/
+  ├── pageobjects/
+  |   └── app.page.js
+  ├── specs/
+  |   ├── app.spec.js
+  └── .eslintrc.js
+```
+
+#### `pageobjects`
+Working with page objects is a popular methodology in end-to-end UI testing. See [working with page objects](https://webdriver.io/docs/pageobjects.html) section for details.
+
+#### `specs`
+The main location where tests are located. You can specify specific tests or define suites to run various subsets of these tests. [More info](https://webdriver.io/docs/organizingsuites.html).
+
+## Installing in an Already Created Project
+
+``` sh
+vue add e2e-webdriverio
+```
+
+## Running Tests
+
+By default, all tests inside the `specs` folder will be run using Chrome. If you'd like to run end-to-end tests against Chrome (or Firefox) in headless mode, simply pass the `--headless` argument.
+
+```sh
+$ vue-cli-service test:e2e
+```
+
+This will run the tests automatically in parallel on Firefox and Chrome.
+
+**Running a single test**
+
+To run a single test supply the filename path. E.g.:
+
+```sh
+$ vue-cli-service test:e2e --spec tests/e2e/specs/test.js
+```