sinon-cheatsheet.js

class Hello {
  constructor(foo, bar) {
    this.foo = foo;
    this.bar = bar;
  }

  otherfun() {
    return 1;
  }

  somefun() {
    if (this.otherfun() === 1) {
      return this.foo;
    }

    if (Hello.magic() === 2) {
      return this.bar;
    }

    return null;
  }

  static magic() {
    return 2;
  }
}

describe('$SUITE$ Hello', () => {
  let hello;
  let sandbox;

  beforeEach(() => {
    hello = new Hello('foo', 'bar');
    sandbox = sinon.sandbox.create({
      useFakeServer: true,
    });
  });

  afterEach(() => {
    sandbox.verifyAndRestore();
  });

  it('other funshould return 1', function() {
    assert(hello.otherfun() === 1);
  });

  it('somefun should return foo', function() {
    assert(hello.somefun() === 'foo');
  });

  it('somefun should return bar', function() {
    sandbox.stub(hello, 'otherfun').returns(2);

    assert(hello.somefun() === 'bar');
  });

  it('somefun should return null', () => {
    const other = sandbox.stub(hello, 'otherfun').returns(2);
    const magic = sandbox.stub(Hello, 'magic').returns(3);

    assert(hello.somefun() === null);
    sinon.assert.callOrder(other, magic);
  });
});