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Frameworks

The WDIO runner currently supports Mocha, Jasmine, and Cucumber.

To integrate each framework with WebdriverIO, there are adapter packages on NPM which must be installed. You cannot install the adapters just anywhere; these packages must be installed in the same location WebdriverIO is installed. So, if you installed WebdriverIO globally, be sure to install the adapter package globally, too.

Within your spec files (or step definitions), you can access the WebDriver instance using the global variable browser. (You don't need to initiate or end the Selenium session. This is taken care of by the wdio testrunner.)

Using Mocha​

First, install the adapter package from NPM:

npm install @wdio/mocha-framework --save-dev

By default WebdriverIO provides an assertion library that is built-in which you can start right away:

describe('my awesome website', () => {
    it('should do some assertions', async () => {
        await browser.url('https://webdriver.io')
        await expect(browser).toHaveTitle('WebdriverIO · Next-gen browser and mobile automation test framework for Node.js | WebdriverIO')
    })
})

WebdriverIO supports Mocha's BDD (default), TDD, and QUnit interfaces.

If you like to write your specs in TDD style, set the ui property in your mochaOpts config to tdd. Now your test files should be written like this:

suite('my awesome website', () => {
    test('should do some assertions', async () => {
        await browser.url('https://webdriver.io')
        await expect(browser).toHaveTitle('WebdriverIO · Next-gen browser and mobile automation test framework for Node.js | WebdriverIO')
    })
})

If you want to define other Mocha-specific settings, you can do it with the mochaOpts key in your configuration file. A list of all options can be found on the Mocha project website.

Note: Since all commands are running synchronously, there is no need to have async mode in Mocha enabled. Therefore, you can't use the done callback:

it('should test something', () => {
    done() // throws "done is not a function"
})

If you want to run something asynchronously, you can either use the browser.call command or custom commands.

Mocha Options​

The following options can be applied in your wdio.conf.js to configure your Mocha environment. Note: not all options are supported, e.g. applying the parallel option will cause an error as the WDIO testrunner has its own way to run tests in parallel. The following options however are supported:

require​

The require option is useful when you want to add or extend some basic functionality (WebdriverIO framework option).

Type: string|string[]
Default: []

compilers​

Use the given module(s) to compile files. Compilers will be included before requires (WebdriverIO framework option).

Type: string[]
Default: []

allowUncaught​

Propagate uncaught errors.

Type: boolean
Default: false

bail​

Bail after first test failure.

Type: boolean
Default: false

checkLeaks​

Check for global variable leaks.

Type: boolean
Default: false

delay​

Delay root suite execution.

Type: boolean
Default: false

fgrep​

Test filter given string.

Type: string
Default: null

forbidOnly​

Tests marked only fail the suite.

Type: boolean
Default: false

forbidPending​

Pending tests fail the suite.

Type: boolean
Default: false

fullTrace​

Full stacktrace upon failure.

Type: boolean
Default: false

global​

Variables expected in global scope.

Type: string[]
Default: []

grep​

Test filter given regular expression.

Type: RegExp|string
Default: null

invert​

Invert test filter matches.

Type: boolean
Default: false

retries​

Number of times to retry failed tests.

Type: number
Default: 0

timeout​

Timeout threshold value (in ms).

Type: number
Default: 30000

Using Jasmine​

First, install the adapter package from NPM:

npm install @wdio/jasmine-framework --save-dev

You can then configure your Jasmine environment by setting a jasmineOpts property in your config. A list of all options can be found on the Jasmine project website.

Intercept Assertion​

The Jasmine framework allows it to intercept each assertion in order to log the state of the application or website, depending on the result.

For example, it is pretty handy to take a screenshot every time an assertion fails. In your jasmineOpts you can add a property called expectationResultHandler that takes a function to execute. The function’s parameters provide information about the result of the assertion.

The following example demonstrates how to take a screenshot if an assertion fails:

jasmineOpts: {
    defaultTimeoutInterval: 10000,
    expectationResultHandler: function(passed, assertion) {
        /**
         * only take screenshot if assertion failed
         */
        if(passed) {
            return
        }

        browser.saveScreenshot(`assertionError_${assertion.error.message}.png`)
    }
},

Note: You cannot stop test execution to do something async. It might happen that the command takes too much time and the website state has changed. (Though usually, after another 2 commands the screenshot is taken anyway, which still gives some valuable information about the error.)

Jasmine Options​

The following options can be applied in your wdio.conf.js to configure your Jasmine environment using the jasmineOpts property:

defaultTimeoutInterval​

Default Timeout Interval for Jasmine operations.

Type: number
Default: 60000

helpers​

Array of filepaths (and globs) relative to spec_dir to include before jasmine specs.

Type: string[]
Default: []

requires​

The requires option is useful when you want to add or extend some basic functionality.

Type: string[]
Default: []

random​

Whether to randomize spec execution order.

Type: boolean
Default: true

seed​

Seed to use as the basis of randomization. Null causes the seed to be determined randomly at the start of execution.

Type: Function
Default: null

failSpecWithNoExpectations​

Whether to fail the spec if it ran no expectations. By default a spec that ran no expectations is reported as passed. Setting this to true will report such spec as a failure.

Type: boolean
Default: false

oneFailurePerSpec​

Whether to cause specs to only have one expectation failure.

Type: boolean
Default: false

specFilter​

Function to use to filter specs.

Type: Function
Default: () => true

grep​

Only run tests matching this string or regexp. (Only applicable if no custom specFilter function is set)

Type: string|Regexp
Default: null

invertGrep​

If true it inverts the matching tests and only runs tests that don't match with the expression used in grep. (Only applicable if no custom specFilter function is set)

Type: boolean
Default: false

Using Cucumber​

First, install the adapter package from NPM:

npm install @wdio/cucumber-framework --save-dev

If you want to use Cucumber, set the framework property to cucumber by adding framework: 'cucumber' to the config file.

Options for Cucumber can be given in the config file with cucumberOpts. Check out the whole list of options here.

To get up and running quickly with Cucumber, have a look on our cucumber-boilerplate project that comes with all the step definitions you need to get stared, and you'll be writing feature files right away.

Cucumber Options​

The following options can be applied in your wdio.conf.js to configure your Cucumber environment using the cucumberOpts property:

backtrace​

Show full backtrace for errors.

Type: Boolean
Default: true

requireModule​

Require modules prior to requiring any support files.

Type: string[]
Default: []
Example:

cucumberOpts: {
    requireModule: ['@babel/register']
    // or
    requireModule: [
        [
            '@babel/register',
            {
                rootMode: 'upward',
                ignore: ['node_modules']
            }
        ]
    ]
 }

failAmbiguousDefinitions​

Treat ambiguous definitions as errors. Please note that this is a @wdio/cucumber-framework specific option and not recognized by cucumber-js itself.

Type: boolean
Default: false

failFast​

Abort the run on first failure.

Type: boolean
Default: false

ignoreUndefinedDefinitions​

Treat undefined definitions as warnings. Please note that this is a @wdio/cucumber-framework specific option and not recognized by cucumber-js itself.

Type: boolean
Default: false

name​

Only execute the scenarios with name matching the expression (repeatable).

Type: RegExp[]
Default: []

profile​

Specify the profile to use.

Type: string[]
Default: []

require​

Require files containing your step definitions before executing features. You can also specify a glob to your step definitions.

Type: string[]
Default: [] Example:

cucumberOpts: {
    require: [path.join(__dirname, 'step-definitions', 'my-steps.js')]
}

snippetSyntax​

Specify a custom snippet syntax.

Type: string
Default: null

snippets​

Hide step definition snippets for pending steps.

Type: boolean
Default: true

source​

Hide source uris.

Type: boolean
Default: true

strict​

Fail if there are any undefined or pending steps.

Type: boolean
Default: false

tagExpression​

Only execute the features or scenarios with tags matching the expression. Please see the Cucumber documentation for more details.

Type: string
Default: null

tagsInTitle​

Add cucumber tags to feature or scenario name.

Type: boolean
Default: false

timeout​

Timeout in milliseconds for step definitions.

Type: number
Default: 30000

Skipping tests in cucumber​

Note that if you want to skip a test using regular cucumber test filtering capabilities available in cucumberOpts, you will do it for all the browsers and devices configured in the capabilities. In order to be able to skip scenarios only for specific capabilities combinations without having a session started if not necessary, webdriverio provides the following specific tag syntax for cucumber:

@skip([condition])

were condition is an optional combination of capabilities properties with their values that when all matched with cause the tagged scenario or feature to be skipped. Of course you can add several tags to scenarios and features to skip a tests under several different conditions.

Here you have some examples of this syntax:

  • @skip(): will always skip the tagged item
  • @skip(browserName="chrome"): the test will not be executed against chrome browsers.
  • @skip(browserName="firefox";platformName="linux"): will skip the test in firefox over linux executions.
  • @skip(browserName=["chrome","firefox"]): tagged items will be skipped for both chrome and firefox browsers.
  • @skip(browserName=/i.*explorer/: capabilities with browsers matching the regexp will be skipped (like iexplorer, internet explorer, internet-explorer, ...).

Import Step Definition Helper​

In order to use step definition helper like Given, When or Then or hooks, you are suppose to import then from @cucumber/cucumber, e.g. like this:

import { Given, When, Then } from '@cucumber/cucumber'

Now, if you use Cucumber already for other types of tests unrelated to WebdriverIO for which you use a specific version you need to import these helpers in your e2e tests from the WebdriverIO Cucumber package, e.g.:

import { Given, When, Then } from '@wdio/cucumber-framework'

This ensures that you use the right helpers within the WebdriverIO framework and allows you to use an independant Cucumber version for other types of testing.