История изменений

const proxyquire = require('proxyquire');
const { assert } = require('chai');
const Sinon = require('sinon');

describe('sum', () => {
  it('sums two numbers', () => {
    const fakeLogger = {
      log: Sinon.stub(),
    };

    const sum = proxyquire('../src/sum', {
      './mylogger': {
        log: fakeLogger.log,
      }
    }).sum;

    assert.equal(sum(1, 2), 3);
    assert(fakeLogger.log.calledOnce);
  });
});