asynchronous test failing with bluebird

failingAsyncTest.js

describe('bluebird', () => { 
  const getPromise = () =>
    Promise.resolve(true);
  	
  it('should allow synchronous behaviour', () => {
    let set = false;
    
    getPromise()
    .then(value => {
    	set = value;
    });
    
    expect(set).toBe(true);
  });
});