In Sinon I can do the following:
var myObj = { prop: \'foo\' }; sinon.stub(myObj, \'prop\').get(function getterFn() { return \'bar\'; }); myObj.prop; /
You could use Object.defineProperty
Object.defineProperty(myObj, 'prop', { get: jest.fn(() => 'bar'), set: jest.fn() });