README.md

sinon-mocha-test

Automatic Sinon sandbox for Mocha/Jest/Vitest tests in Javascript and Typescript.

A utility function which wraps a test and automatically removes mocks.

Installation

npm install sinon-mocha-test

Usage

import { promises as fs } from 'fs';
import assert from 'assert';
import sinonTest from 'sinon-mocha-test';

/** Example function to test */
async function readJsonFile(path) {
  return JSON.parse((await fs.readFile(path)).toString());
}

describe('readJsonFile', () => {
  it('Resolves with the data from a JSON file', sinonTest(async (sinon) => {
    const readFile = sinon.stub(fs, 'readFile').resolves('{"version":"123"}\n');
    assert.deepStrictEqual(await readJsonFile('file.json'), { version: '123' });
    assert.strictEqual(readFile.callCount, 1);
  }));
});

Or with Vitest:

import { test, describe } from 'vitest'
import { promises as fs } from 'fs';
import assert from 'assert';
import sinonTest from 'sinon-mocha-test';

/** Example function to test */
async function readJsonFile(path) {
  return JSON.parse((await fs.readFile(path)).toString());
}

describe('readJsonFile', () => {
  test('Resolves with the data from a JSON file', () => {
    assert.strictEqual(1, 1);
  });

  test('Resolves with the data from a JSON file', sinonTest(async (sinon) => {
    const readFile = sinon.stub(fs, 'readFile').resolves('{"version":"123"}\n');
    assert.deepStrictEqual(await readJsonFile('file.json'), { version: '123' });
    assert.strictEqual(readFile.callCount, 1);
  }));
});

Custom sandbox options

Use sinonTest.create to specify custom Sinon sandbox options:

import sinonTest from 'sinon-mocha-test';

/** Example function to test */
async function delay(time) {
  return new Promise((resolve) => {
    setTimeout(resolve, time);
  });
}

describe('delay', () => {
  it('Resolves after a delay', sinonTest.create({ useFakeTimers: false }, async (sinon) => {
    await delay(10);
  }));
});

With CommonJS / require()

const assert = require('assert');
const sinonTest = require('sinon-mocha-test');

/** Example function to test */
function logger(message) {
  console.log(message);
}

describe('logger', () => {
  it('Resolves after a delay', sinonTest(function(sinon) {
    const log = sinon.stub(console, 'log');
    logger('Hello world');
    assert.strictEqual(log.callCount, 1);
    assert(log.calledWith('Hello world'));
  }));
});