nock

import nock from 'nock'; import { strict as assert } from 'node:assert'; // Define the base URL for the API to mock const API_BASE_URL = 'http://api.example.com'; const FAKE_API_PATH = '/users/123'; async function getUserData(userId: string) { const response = await fetch(`${API_BASE_URL}/users/${userId}`, { headers: { 'Accept': 'application/json' } }); if (!response.ok) { throw new Error(`HTTP error! Status: ${response.status}`); } return response.json(); } async function runTest() { // 1. Set up the Nock interceptor for a GET request const scope = nock(API_BASE_URL) .matchHeader('Accept', 'application/json') .get(FAKE_API_PATH) .reply(200, { id: '123', name: 'Nock User', email: 'user@example.com' }, { 'Content-Type': 'application/json', 'X-Nock-Mocked': 'true', 'Cache-Control': 'no-cache' }); try { // 2. Make the HTTP request that Nock will intercept console.log('Fetching user data...'); const userData = await getUserData('123'); // 3. Assert the response data matches the mock assert.deepStrictEqual(userData, { id: '123', name: 'Nock User', email: 'user@example.com' }, 'User data should match mock payload.'); console.log('Successfully received mocked user data.'); // 4. Assert that all Nock expectations were met for this scope assert(scope.isDone(), 'Nock scope should be done, all expectations met.'); console.log('Nock expectations met for the defined scope.'); } catch (error) { console.error('Test failed:', error); process.exit(1); } finally { // 5. Clean up Nock mocks to prevent interference with other tests nock.cleanAll(); console.log('Nock mocks cleaned up.'); } } // Ensure Nock is active; often implicit after import, but good for clarity nock.activate(); runTest();