In-process mock API: resources + HTTP routes, middleware, health, SSE/WS.

Mock HTTP server for testing HTTP clients and stubbing webservices

Seamless REST/GraphQL API mocking library for browser and Node.js.

Easily mock NodeJS process properties in Jest

Mock infrastructure for AI application testing — point your SDK at one local port and every provider, protocol, and service answers deterministically.

Easy and powerful mocking of AWS SDK v3 Clients

Mock a canvas in your jest tests.

Axios adapter that allows to easily mock requests

An in-process mock of Steam's Inventory Service (ISteamInventory): exchange formulas, bundle and generator expansion, per-item tags, tag tools, dynamic properties, playtime drops and promo grants — driven by a virtual clock and a seedable RNG.

fetch mock for jest

A Mock API for AWS Kinesis

OAuth2 and OpenID Connect mock server for automated testing and development. Issues cryptographically signed JWTs via JWK key pairs. OIDC-conformant, exposes discovery, JWKS, authorization, token, userinfo, introspection, revocation, and end-session endpo

**Note:** More details on user side API can be found in [Jest documentation](https://jestjs.io/docs/mock-function-api).

Lightweight Jest compatible spy implementation

This library emulates ioredis by performing all operations in-memory.

Mock http requests made using fetch

Custom Jest matchers for AWS SDK v3 Client mock

A configurable mock file system. You know, for testing.

Mock `window.Date` when run unit test cases with jest. Make tests of `Date` easier.

A lightweight Jest mock for unit testing Express