Implementation:DevExpress Testcafe RequestHook TypeDefs

Knowledge Sources	DevExpress_Testcafe TestCafe Request Hooks
Domains	Type_Definitions, Testing, Request_Interception
Last Updated	2026-02-12 12:00 GMT

Overview

Concrete TypeScript type declarations for TestCafe's request interception APIs: RequestHook, RequestLogger, and RequestMock.

Description

This file defines the type declarations for TestCafe's request hooks. RequestHook is the abstract base class for custom hooks with onRequest and onResponse methods. RequestLogger records HTTP traffic with filter rules and provides query methods (contains, count, requests). RequestMock enables response mocking with a fluent builder API (onRequestTo().respond()). These hooks are attached to tests or fixtures and can be dynamically managed via t.addRequestHooks().

Usage

Use these types when implementing custom request hooks, logging HTTP traffic in tests, or mocking API responses.

Code Reference

Source Location

• Repository: DevExpress_Testcafe
• File: ts-defs-src/test-api/request-hook.d.ts
• Lines: 1-215

Signature

declare class RequestHook {
    constructor(requestFilterRules?: Array<any>, responseEventConfigureOpts?: object);
    onRequest(event: object): Promise<void>;
    onResponse(event: object): Promise<void>;
}

declare class RequestLogger extends RequestHook {
    constructor(filter?: string | RegExp | object | ((req: any) => boolean),
                options?: { logRequestHeaders?: boolean; logRequestBody?: boolean;
                           logResponseHeaders?: boolean; logResponseBody?: boolean;
                           stringifyResponseBody?: boolean; stringifyRequestBody?: boolean; });
    contains(predicate: (request: LoggedRequest) => boolean): Promise<boolean>;
    count(predicate: (request: LoggedRequest) => boolean): Promise<number>;
    requests: LoggedRequest[];
    clear(): void;
}

declare class RequestMock {
    onRequestTo(filter: string | RegExp | object | ((req: any) => boolean)): RequestMock;
    respond(body?: object | string | Function, statusCode?: number, headers?: object): RequestMock;
}

Import

import { RequestHook, RequestLogger, RequestMock } from 'testcafe';

I/O Contract

Inputs

Name	Type	Required	Description
filter	string, RegExp, object, function	No	URL or predicate to match requests
options	object	No	Logger options (log headers, body, etc.)
body	object, string, Function	No	Mock response body
statusCode	number	No	Mock response status code

Outputs

Name	Type	Description
RequestLogger.requests	LoggedRequest[]	Array of recorded request/response pairs
RequestLogger.contains()	Promise<boolean>	Whether any logged request matches predicate
RequestMock	RequestMock	Chainable mock builder

Usage Examples

import { RequestLogger, RequestMock, RequestHook } from 'testcafe';

// 1. Request Logger - record API calls
const logger = RequestLogger(/api\/users/, {
    logRequestBody: true,
    logResponseBody: true,
    stringifyResponseBody: true,
});

fixture('Request Hooks').page('https://example.com');

test.requestHooks(logger)('Log API calls', async (t: TestController) => {
    await t.click('#load-users');
    await t.expect(logger.count(r => r.response.statusCode === 200)).eql(1);
    console.log(logger.requests[0].response.body);
});

// 2. Request Mock - mock API responses
const mock = RequestMock()
    .onRequestTo('https://api.example.com/users')
    .respond({ users: [{ id: 1, name: 'Test' }] }, 200, {
        'content-type': 'application/json',
    });

test.requestHooks(mock)('Mocked API', async (t: TestController) => {
    await t.click('#load-users');
    await t.expect(Selector('.user').count).eql(1);
});

Related Pages

• Environment:DevExpress_Testcafe_Node_Runtime