Is it possible to use a Jasmine spy on a fresh instance?

In need of assistance with testing a TypeScript method (eventually testing the actual JavaScript) that I'm having trouble with. The method is quite straightforward:

private static myMethod(foo: IFoo): void {
    let anInterestingThing = new InterestingThing();
    foo.bar = anInterestingThing.getSomethingCool();
}

I am looking to verify that getSomethingCool has been called during testing, but I am unsure on how to spy on the new anInterestingThing object. Does anyone know the most effective approach for achieving this?

javascripttypescriptjasmine

Answer №1

Assuming fetchData is a method within the FetchAPI class, you can use the following code snippet:

jest.spyOn(FetchAPI.prototype, "fetchData");

Nevertheless, this approach may be vulnerable to changes in the FetchAPI class structure. The method fetchData could become an instance method or may be accessed differently during the static initialization process.

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