chai-fetch-mock

library3.0.0jsnpmunverified

Chai plugin for fetch-mock library version 3.0.0. Provides Chai assertions for fetch-mock, a mocking library for fetch() and isomorphic-fetch. Active maintenance, weekly release cadence. Differentiator: adds fluent BDD-style assertions like `.called`, `.with.args()`, `.with.url()`, `.with.options()` for fetch-mock routes, requiring careful ordering with other Chai plugins. Supports Node.js 7+ and Chai 3.x/4.x, fetch-mock 5.1.x/6.x. Note: fetch-mock 6.0 requires Node >=7.

testing

npm install chai-fetch-mock

github ↗package ↗homepage ↗

INSTALL

IMPORT

SIG · CHAI-FETCH-MOCK

chai-fetch-mock

testingjavascriptv3.0.0

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.

default (chaiFetchMock)

✓ import chaiFetchMock from 'chai-fetch-mock'

✗ const chaiFetchMock = require('chai-fetch-mock')

ESM-only export; use import statement or dynamic import()

chai.use

✓ chai.use(chaiFetchMock)

✗ chai.use('chai-fetch-mock')

Pass the plugin function, not a string

expect(fetchMock).route(...)

✓ expect(fetchMock).route('/cats').to.have.been.called

✗ expect(fetchMock).to.have.been.called.route('/cats')

route() must be called before other assertions, not after

Sets up a fetch mock, applies the chai-fetch-mock plugin, and uses various route assertions.

import chai from 'chai'; import chaiFetchMock from 'chai-fetch-mock'; import fetchMock from 'fetch-mock'; chai.use(chaiFetchMock); const { expect } = chai; before(() => fetchMock.get('/cats', { cats: 5 })); expect(fetchMock).route('/cats').to.have.been.called; expect(fetchMock).route('/cats').to.have.been.called.with.args(['/cats', { cats: 5 }]); expect(fetchMock).route('/cats').to.have.been.called.with.url('/cats'); expect(fetchMock).route('/cats').to.have.been.called.with.options({ method: 'GET' }); after(() => fetchMock.restore());

Debug

Known issues

gotchaRoute must be defined via route() before using .called, .with.args, .with.url, or .with.options

fix

Always start the assertion chain with .route(urlOrName), e.g., expect(fetchMock).route('/path').to.have.been.called

affects: >=1.0.0

gotchaApply chai-fetch-mock after other plugins like sinon-chai to avoid conflicts with similar vocabulary (e.g., called)

fix

Order plugin registration: sin·on-chai first, then chai-fetch-mock

affects: >=1.0.0

deprecatedfetch-mock 6.x is required for Node >=7; support for fetch-mock 5.x may be dropped

fix

Update to fetch-mock >=6.0.0 and Node >=7

affects: >=3.0.0

gotcha`.with.args()` asserts deep equality of the entire arguments array, not just the URL

fix

Pass array of arguments: [url, options]

affects: >=1.0.0

gotchaAssertions are asynchronous; ensure the fetch call has completed before making assertions (e.g., inside .then() or async/await)

fix

Place assertions inside the .then() callback after the fetch promise resolves

affects: >=1.0.0

Errors

Common errors & fixes

TypeError: chai.use is not a function

chai.use is invoked on a string instead of the chai object

fix

const chai = require('chai') or import chai from 'chai'

AssertionError: expected [Function] to have been called

Forgetting to call .route() before .called

fix

Add .route('/path') before .to.have.been.called

TypeError: Cannot read property 'route' of undefined

fetchMock is not passed to expect() or is undefined

fix

Make sure fetchMock is imported and passed: expect(fetchMock).route(...)

Upgrade

Version history

3.0.0latest on npm

Audit

Dependencies

chairequiredPeer dependency; plugin extends chai assertions

fetch-mockrequiredPeer dependency; provides the mock fetch object

Agent activity

16 hits · last 30 days

node

OpenAI (training)

Resources

githubhttps://github.com/gakimball/chai-fetch-mock ↗

packagechai-fetch-mock ↗

homepagehttps://github.com/gakimball/chai-fetch-mock#readme ↗