Jest-Sinon

Jest-Sinon is a collection of assertions for using the mocking library Sinon.js with Jest.

Example

const bar = () => {};
const foo = sinon.spy();

foo(bar);

// instead of:
expect(foo.calledWith(bar)).toBeTruthy;

// we can write:
expect(foo).toHaveBeenCalledWith(bar);

The assertions: toHaveBeenCalledTimes, toThrow, toReturnWith, toHaveBeenCalled and toHaveBeenCalledWith clash with the in-built Jest mocking framework. Jest-Sinon will try and detect which type of spy is being used and use the correct assertion. You should be able to use both mocking libraries in parallel.

const foo = sinon.spy();
const bar = jest.fn();

foo();
bar();

expect(foo).toHaveBeenCalled(); // true
expect(bar).toHaveBeenCalled(); // true

Why?

There are a number of reasons why you might want to use Sinon.js instead of (or as well as) the in-built mocking assertions. Some of the use cases include:

• Developer preference/familiarity to Sinon.js
• Migrating a code base from Mocha/Chai/Sinon to Jest
• To be difficult

Ultimately, it usually comes down to your own preferences and needs.

Installation

With npm:

npm install --save-dev jest-sinon

With yarn:

yarn add -D jest-sinon

Setup

Jest 24+

Add Jest-Sinon to your Jest setupFilesAfterEnv configuration.

"jest": {
  "setupFilesAfterEnv": ["jest-sinon"]
}

Jest 23 or below

"jest": {
  "setupTestFrameworkScriptFile": "./testSetup.js"
}

// testSetup.js

require('jest-sinon');

Usage

Jest-Sinon adds a number of assertions to help test Sinon.js Spies, Mocks and Stubs. Below is a list of currently implemented assertions.

.toHaveBeenAlwaysCalledOn(obj)

Also under the alias: .toBeAlwaysCalledOn()

.toHaveBeenAlwaysCalledWith(args1, arg2, ...)

Also under the alias: .toBeAlwaysCalledWith()

.toHaveBeenAlwaysCalledWithExactly(args1, arg2, ...)

Also under the alias: .toBeAlwaysCalledWithExactly()

.toHaveBeenAlwaysCalledWithMatch(arg1, arg2, ...)

Also under the alias: .toBeAlwaysCalledWithMatch()

.toHaveBeenAlwaysCalledWithNew()

Also under the alias: .toBeAlwaysCalledWithNew()

.toHaveBeenCalled()

Also under the alias: .toBeCalled()

.toHaveBeenCalledAfter(anotherSpy)

Also under the alias: .toBeCalledAfter()

.toHaveBeenCalledBefore(anotherSpy)

Also under the alias: .toBeCalledBefore()

.toHaveBeenCalledImmediatelyAfter(anotherSpy)

Also under the alias: .toBeCalledImmediatelyAfter()

.toHaveBeenCalledImmediatelyBefore(anotherSpy)

Also under the alias: .toBeCalledImmediatelyBefore()

.toHaveBeenCalledOn(obj)

Also under the alias: .toBeCalledOn()

.toHaveBeenCalledOnce()

Also under the alias: .toBeCalledOnce()

.toHaveBeenCalledOnceWith(arg1, arg2, ...)

Also under the alias: .toBeCalledOnceWith()

.toHaveBeenCalledOnceWithExactly(arg1, arg2, ...)

Also under the alias: .toBeCalledOnceWithExactly()

.toHaveBeenCalledThrice()

Also under the alias: .toBeCalledThrice()

.toHaveBeenCalledTwice()

Also under the alias: .toBeCalledTwice()

.toHaveBeenCalledWith(arg1, arg2, ...)

Also under the alias: .toBeCalledWith()

.toHaveBeenCalledWithExactly(arg1, arg2, ...)

Also under the alias: .toBeCalledWithExactly()

.toHaveBeenCalledWithMatch(arg1, arg2, ...)

Also under the alias: .toBeCalledWithMatch()

.toHaveBeenCalledWithNew()

Also under the alias: .toBeCalledWithNew()

.toHaveCallCount(number)

Also under the alias: .toHaveBeenCalledTimes() and .toBeCalledTimes()

.toHaveReturnedWith(obj)

Also under the alias: .toReturnWith(), .toHaveReturned() and .toReturn()

.toHaveAlwaysReturnedWith(obj)

Also under the alias: .toAlwaysReturnWith()

.toHaveThrown(error?)

Also under the alias: .toHaveThrownError(), .toThrow(), and .toThrowError()

.toHaveAlwaysThrown(error?)

Also under the alias: .toHaveAlwaysThrownError(), .toAlwaysThrow() and .toAlwaysThrowError()

For more information about what these do, you can visit Sinon.js.

Contributing

Pull requests for new features, bug fixes, and suggestions are welcome!