RequestHook Constructor

Initializes the request hook.

class TemplateRequestHook extends RequestHook {
    constructor (requestFilterRules, responseEventOptions) {
        /* ... */
    }
}

Parameter	Type	Description
requestFilterRules	String | RegExp | Object | Predicate | Array	Specifies which requests the hook should handle. See Select Requests to be Handled by the Hook.
responseEventOptions	Object	The responseEventOptions.includeHeaders and responseEventOptions.includeBody properties indicate if the response’s headers and body should be passed to the onResponse method.

Pass the requestFilterRules and responseEventOptions parameters to the base class constructor. This enables TestCafe to handle and apply these settings:

class MyRequestHook extends RequestHook {
    constructor (requestFilterRules, responseEventOptions) {
        super(requestFilterRules, responseEventOptions);
    }
}

Select Requests to be Handled by the Hook

Filter by URL

Specify the Exact URL

Pass a string with a URL to intercept all requests sent to this exact URL.

const logger = RequestLogger(['https://devexpress.github.io/testcafe/example/', 'http://localhost:8080']);

const mock = RequestMock()
    .onRequestTo('http://external-service.com/api/')
    .respond('Mocked respond');

Use a Regular Expression to Specify the URL

You can also specify a regular expression that matches the desired URLs.

const logger = RequestLogger(/example/);

const mock = RequestMock()
    .onRequestTo(/\/api\/users\//)
    .respond('Mocked respond');

Filter by Parameters

You can filter requests by combining the URL and the request method.

In this instance, you need to use an object that contains the following fields:

Property	Type	Description
url	String	A URL to which a request is sent.
method	String	The request method.
isAjax	Boolean	Specifies whether this is an AJAX request.

const logger = RequestLogger({ url: 'https://devexpress.github.io/testcafe/example/', method: 'GET', isAjax: false });

const mock = RequestMock()
    .onRequestTo({ url: 'http://external-service.com/api/users/', method: 'POST', isAjax: true })
    .respond((req, res) => {
        res.headers['access-control-allow-origin'] = '*';
        res.setBody(JSON.stringify('users'));
    });

Filter with a Predicate

You can get more request parameters and determine whether to handle the request with the predicate functions.

const logger = RequestLogger(async request => {
    return request.method === 'post' &&
           request.headers['content-type'] === 'text/plain;charset=UTF-8';
});

const mock = RequestMock()
    .onRequestTo(async request => {
        return request.url === 'http://external-service.com/api/users/' &&
               request.method === 'post' &&
               request.isAjax &&
               request.body.toString() === 'foo=bar';
    })
    .respond((req, res) => {
        res.headers['access-control-allow-origin'] = '*';
        res.setBody(JSON.stringify('users'));
    });

This predicate takes the request parameter that provides the following properties:

Property	Type	Description
userAgent	String	Identifies the user agent that originated the request. Contains the formatted name and version of the browser and operating system (Firefox 69.0 / Windows 10.0.0, Chrome 77.0.3865.120 / macOS 10.15.1).
url	String	The URL to which the request is sent.
method	String	The request method.
isAjax	Boolean	Specifies whether this is an AJAX request.
headers	Object	The request headers in the property-value form.
body	String	A stringified request body.