RequestMock.onRequestTo().respond Method

Specifies the mock response.

requestMock.onRequestTo().respond([body] [, statusCode] [, headers]) → this

Parameter	Type	Description	Default
`body` (optional)	Object \| String \| Function \| Buffer	A mocked response body. Pass an object for a JSON response, a string for an HTML response or a function to build a custom response.	An empty HTML page is returned with the response.
`statusCode` (optional)	Number	The response status code.	`200`
`headers` (optional)	Object	Custom headers added to the response in the property-value form.	The `content-type` header. If the header is not provided, it is set depending on the `body` parameter’s type. If `body` is an object, the `content-type` header is set to application/json. If `body` has another type, the `content-type` header is set to text/html; charset=utf-8.

const mock = RequestMock()
    .onRequestTo('https://devexpress.github.io/testcafe/example/json')
    .respond({ data: 123 }) // a JSON response
    .onRequestTo('https://devexpress.github.io/testcafe/example/html')
    .respond('<html></html>') // an HTML response
    .onRequestTo('https://devexpress.github.io/testcafe/example/empty')
    .respond(null, 204) // an empty response with a status code
    .onRequestTo('https://devexpress.github.io/testcafe/example/headers')
    .respond('<html_markup>', 200, { // a response with custom headers
        'server': 'nginx/1.10.3',
    })
    .onRequestTo('https://devexpress.github.io/testcafe/example/binary')
    .respond(Buffer.from([0x62, 0x75, 0x66, 0x66, 0x65, 0x72])) // a response with binary data
    .onRequestTo(/\/custom\?.*/)
    .respond((req, res) => { // a custom response
        res.headers['x-calculated-header'] = 'calculated-value';
        res.statusCode                     = '200';

        const parsedUrl = url.parse(req.url, true);

        res.setBody('calculated body ' + parsedUrl.query['param']);
    });

A Custom Response Function

const templateMock = RequestMock()
    .onRequestTo(/\*...\*/)
    .respond((req, res) => {
        // ...
    });

A custom response function takes two parameters.

Parameter	Type	Description
`req`	RequestOptions	A request to be mocked.
`res`	Object	A mocked response.

Use information provided by the req parameter about the request to configure the response using the res parameter.

The res exposes the following members:

Property	Type	Description
`headers`	Object	The response headers.
`statusCode`	Number	The response status code.

Method	Description
`setBody(value)`	Sets the response body. Accepts a string as a parameter.

The response function can be synchronous or asynchronous:

const mock = RequestMock()
    .onRequestTo('https://devexpress.github.io/testcafe/example/page')
    .respond((req, res) => {
        res.setBody('<html><body><h1>This is a page</h1></body></html>');
    })
    .onRequestTo('https://devexpress.github.io/testcafe/example/todo')
    .respond(async (req, res) => {
        const data = await promisifiedHttpsGet('https://jsonplaceholder.typicode.com/todos/1');

        res.headers['access-control-allow-origin'] = '*';
        res.setBody(data.body);
    });

RequestOptions

The RequestOptions object contains the request parameters.

Property	Type	Description
`headers`	Object	The request headers in the property-value form.
`body`	Buffer	The request body.
`url`	String	The URL to which the request is sent.
`protocol`	String	The protocol to use. Default: http:.
`hostname`	String	The alias for the host.
`host`	String	The domain name or IP address of the server to issue the request to. Default: localhost.
`port`	Number	The port of the remote server. Default: 80.
`path`	String	The request path. Should include query string if any. E.G. ‘/index.html?page=12’. An exception is thrown when the request path contains illegal characters. Currently, only spaces are rejected but that may change in the future. Default: ‘/‘.
`method`	String	The string specifying the HTTP request method. Default: ‘GET’.
`credentials`	Object	Credentials to use for Windows (NTLM) or Basic authentication. HTTP Basic authentication requires a `username` and a `password`. NTLM authentication services may need to know your `workstation` and `domain`. See HTTP Authentication.
`proxy`	Object	If a proxy is used, the property contains information about its `host`, `hostname`, `port`, `proxyAuth`, `authHeader` and `bypassRules`.