mock

Mock the response of a request. You can define a mock based on a matching glob and corresponding header and status code. Calling the mock method returns a stub object that you can use to modify the response of the web resource.

With the stub object you can then either return a custom response or have the request fail.

There are 3 ways to modify the response:

return a custom JSON object (for stubbing API request)
replace web resource with a local file (service a modified JavaScript file) or
redirect resource to a different url

info

Note that using the mock command requires support for Chrome DevTools protocol and e.g. can not be used when running automated tests in the cloud. Find out more in the Automation Protocols section.

Usage#

browser.mock(url, { method, headers, responseHeaders, postData, statusCode })

Parameters#

Name	Type	Details
`url`	`String`	url to mock
`filterOptions` optional	`MockFilterOptions`	filter mock resource by additional options
`filterOptions.method` optional	`String`, `Function`	filter resource by HTTP method
`filterOptions.headers` optional	`Object`, `Function`	filter resource by specific request headers
`filterOptions.responseHeaders` optional	`Object`, `Function`	filter resource by specific response headers
`filterOptions.postData` optional	`String`, `Function`	filter resource by request postData
`filterOptions.statusCode` optional	`Number`, `Function`	filter resource by response statusCode

Example#

mock.js

it('should mock network resources', () => {
    // via static string
    const userListMock = browser.mock('**' + '/users/list')
    // you can also specifying the mock even more by filtering resources
    // by request or response headers, status code, postData, e.g. mock only responses with specific
    // header set and statusCode
    const strictMock = browser.mock('**', {
        // mock all json responses
        statusCode: 200,
        headers: { 'Content-Type': 'application/json' },
        responseHeaders: { 'Cache-Control': 'no-cache' },
        postData: 'foobar'
    })

    // comparator function
    const apiV1Mock = browser.mock('**' + '/api/v1', {
        statusCode: (statusCode) => statusCode >= 200 && statusCode <= 203,
        headers: (headers) => headers['Authorization'] && headers['Authorization'].startsWith('Bearer '),
        responseHeaders: (headers) => headers['Impersonation'],
        postData: (data) => typeof data === 'string' && data.includes('foo')
    })
})

it('should modify API responses', () => {
    // filter by method
    const todoMock = browser.mock('**' + '/todos', {
        method: 'get'
    })

    // mock an endpoint with a fixed fixture
    mock.respond([{
        title: 'Injected Todo',
        order: null,
        completed: false,
        url: "http://todo-backend-express-knex.herokuapp.com/916"
    }])

    // respond with different status code or header
    mock.respond([{
        title: 'Injected Todo',
        order: null,
        completed: false,
        url: "http://todo-backend-express-knex.herokuapp.com/916"
    }], {
        statusCode: 404,
        headers: {
            'x-custom-header': 'foobar'
        }
    })
})

it('should modify text assets', () => {
    const scriptMock = browser.mock('**' + '/script.min.js')
    scriptMock.respond('./tests/fixtures/script.js')
})

it('should redirect web resources', () => {
    const headerMock = browser.mock('**' + '/header.png')
    headerMock.respond('https://media.giphy.com/media/F9hQLAVhWnL56/giphy.gif')

    const pageMock = browser.mock('https://google.com/')
    pageMock.respond('https://webdriver.io')
    browser.url('https://google.com')
    console.log(browser.getTitle()) // returns "WebdriverIO · Next-gen browser and mobile automation test framework for Node.js"
})