bun-fetch-mock

library1.0.2jsnpmunverified

A fetch mocking library designed specifically for Bun's runtime (≥1.0.0). Version 1.0.2 provides a simple API for mocking HTTP requests in Bun tests with TypeScript support. Key differentiators: zero external dependencies, first-class Bun integration (no polyfills needed), assertion helpers to verify all mocks were used, and support for dynamic responses. Released as MIT, actively maintained on GitHub.

testing

npm install bun-fetch-mock

github ↗package ↗homepage ↗

INSTALL

IMPORT

SIG · BUN-FETCH-MOCK

bun-fetch-mock

testingjavascriptv1.0.2

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.

useFetchMock

✓ import { useFetchMock } from 'bun-fetch-mock'

✗ const { useFetchMock } = require('bun-fetch-mock')

Package is ESM-only and uses named exports. Use ES import syntax.

FetchMock

✓ import type { FetchMock } from 'bun-fetch-mock'

Type import for TypeScript users if they need the return type explicitly.

useFetchMock in CommonJS

✓ const { useFetchMock } = await import('bun-fetch-mock')

✗ const { useFetchMock } = require('bun-fetch-mock')

CommonJS require is not supported; use dynamic import with await.

Demonstrates basic usage: initialize mock inside describe, define routes, and verify all mocks are used.

import { describe, test, expect } from 'bun:test'; import { useFetchMock } from 'bun-fetch-mock'; describe('api', () => { const fetchMock = useFetchMock({ baseUrl: 'https://api.example.com' }); test('mocks fetch', async () => { fetchMock .get('/users/1', { data: { id: 1, name: 'Ada' }, once: true }) .get('/users/1', { status: 404, data: { error: 'Not found' } }); const okRes = await fetch('https://api.example.com/users/1'); expect(await okRes.json()).toEqual({ id: 1, name: 'Ada' }); const notFoundRes = await fetch('https://api.example.com/users/1'); expect(notFoundRes.status).toBe(404); fetchMock.assertAllMocksUsed(); }); });

Debug

Known issues

gotchaInitialize useFetchMock() inside describe block, not inside test blocks

fix

Move useFetchMock() call to describe scope.

affects: >=1.0.0

gotchamock.get('path') without trailing slash does not match requests with trailing slash

fix

Ensure path consistency between mocked routes and actual fetch calls.

affects: >=1.0.0

gotchaassertAllMocksUsed() must be called at the end of each test to verify all mocks were consumed

fix

Call fetchMock.assertAllMocksUsed() before the test ends.

affects: >=1.0.0

Errors

Common errors & fixes

TypeError: fetch is not defined

The package expects Bun's global fetch to be available. In Node.js or other runtimes, fetch might not be globally defined.

fix

Ensure you are running tests with Bun (bun test) or polyfill fetch globally.

Cannot find module 'bun-fetch-mock'

Package not installed or installed incorrectly (e.g., in wrong directory).

fix

Run 'bun add -d bun-fetch-mock' from the correct project root.

Upgrade

Version history

1.0.2latest on npm

Audit

Dependencies

No dependency data recorded yet.

Agent activity

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Resources

githubhttps://github.com/lilienblum/bun-fetch-mock ↗

packagebun-fetch-mock ↗

homepagehttps://github.com/lilienblum/bun-fetch-mock#readme ↗