Unit testing a select element

I am having difficulty unit testing a select element bound to an asynchronous method.
No matter what i do, i get Timeout - Async callback was not invoked… by jasmine

The code:

public units = [];
setTimeout(() => {
   this.units = ["per Hour", "per Annum", "per Day"]
}, 100);

The test:

it("please work", (done) => {
    component.create(bootstrap).then(() => {
	    component.waitForElement(`select[name="units"]`, {}).then((element: HTMLSelectElement) => {
 	        expect(element.options.length).toBe(4);
            done();
        });
   });
});

I can convert this to a static method and the test works. I’ve tried set timeouts, in the waitForElement options, at various entries before the expectation.

I have found the answer to my own problem. It is increasing the default timeout interval.