fakerest

library4.2.1jsnpmunverified

A browser library that intercepts AJAX calls to mock a REST server based on JSON data. Version 4.2.1 includes TypeScript types and supports MSW, fetch-mock, and Sinon for interception. It enables client-side testing of SPA REST clients without a live server by patching XMLHttpRequest or fetch. Differentiators include out-of-box support for multiple mocking libraries, automatic CRUD routes from a simple data object (resources with records), and compatibility with react-admin. Release cadence is stable with periodic updates.

testing

npm install fakerest

github ↗package ↗homepage ↗

INSTALL

IMPORT

SIG · FAKEREST

fakerest

testingjavascriptv4.2.1

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

getMswHandler

✓ import { getMswHandler } from 'fakerest'

✗ const getMswHandler = require('fakerest').getMswHandler

ESM-only since v4; CJS require() fails in Node (browser lib).

getFetchMockHandler

✓ import { getFetchMockHandler } from 'fakerest'

Named export, no default export. TypeScript types included.

getSinonHandler

✓ import { getSinonHandler } from 'fakerest'

✗ import FakeRest from 'fakerest'

No default export; import specific handler functions only.

Creates an MSW handler that intercepts all fetch requests to localhost:3000 and returns REST-like responses based on provided JSON data.

import { http } from 'msw'; import { setupWorker } from 'msw/browser'; import { getMswHandler } from 'fakerest'; const handler = getMswHandler({ baseUrl: 'http://localhost:3000', data: { authors: [ { id: 0, first_name: 'Leo', last_name: 'Tolstoi' }, { id: 1, first_name: 'Jane', last_name: 'Austen' } ], books: [ { id: 0, title: 'War and Peace' }, { id: 1, title: 'Pride and Prejudice' } ] } }); export const worker = setupWorker( http.all(/http:\/\/localhost:3000/, handler) ); worker.start({ quiet: true, onUnhandledRequest: 'bypass' });

Debug

Known issues

gotchaThe data object must have string keys for resource names; nested objects within a resource are treated as strings, not automatically expanded.

fix

Ensure each resource is an array of objects (for list) or a single object (for singleton).

affects: *

gotchaOnly supports RESTful requests for resources; non-REST endpoints (e.g., /auth) will return 404 unless manually handled.

fix

Add custom handlers via MSW/fetch-mock/Sinon for non-REST routes.

affects: *

gotchaUsing with MSW requires a RegExp or string matcher, not a function matcher, for the handler to work correctly.

fix

Use http.all(/\/api\//, handler) instead of http.all('*/api/*', handler).

affects: >=4.0

Errors

Common errors & fixes

TypeError: Cannot read properties of undefined (reading 'id')

Data object missing an 'id' field in one of the resource arrays.

fix

Ensure all resource items have an 'id' property (or configure idAttribute in options).

Error: [MSW] Failed to register a service worker

MSW service worker not initialized or wrong public directory.

fix

Run `npx msw init public` (or your public dir) to generate the mockServiceWorker.js file.

FakeRest: unknown resource 'settings'

Data object contains a non-array top-level key; FakeRest expects arrays for resources (except singleton).

fix

Wrap singleton data in an array or use a singleton resource pattern (see docs).

Upgrade

Version history

4.2.1latest on npm

Audit

Dependencies

No dependency data recorded yet.

Agent activity

4 hits · last 30 days

node

Resources

githubhttps://github.com/marmelab/FakeRest ↗

packagefakerest ↗

homepagehttps://github.com/marmelab/FakeRest#readme ↗