Spy.callData -- What's Spy.callData used for?, how to use it?

[dancer1325]

In https://jasmine.github.io/api/edge/Spy.html, you can find

(static) callData
Properties:
...

• Questions

  • What can it be used for?

  • How to use it?

  • Since it's static, as soon as you create the Spy via any method, it will be ever and ever undefined, invoking or not the spy

    ...
    const spy = jasmine.createSpy('getSomething');
            // 1.1 BEFORE being invoked the spy     
            console.log("BEFORE invoking the spy -- spy.callData ", spy.callData);     // undefined
            
            // 1.2 AFTER invoking the spy    
            spy('arg1', 42);
            spy('arg2');
            console.log("AFTER invoking the spy -- spy.callData ", spy.callData);     //    STILL undefined
    ...
    

  • Only to get detailed information through Spy.calls?

      const spy = jasmine.createSpy('spy');
  
      console.log("BEFORE INVOKING - spy.calls.mostRecent() ", spy.calls.mostRecent());     // undefined
      spy(1, 2, 3);
      spy('a', 'b', 'c');
      console.log("AFTER INVOKING - spy.calls.mostRecent() ", spy.calls.mostRecent());  // current callData
  

Note

• NOT sure if "issue" is the best way to raise up a question, but I did NOT find another channel or indications

[sgravrock]

An instance of callData represents a single call to a spy. You can access them through a specific spy's .calls property, as you noticed. callData is used by the spy-related matchers like toHaveBeenCalledWith, and you can also write your own matching logic that uses it.

There isn't actually a static Spy.callData property. I don't know for sure, but my guess is that it was marked up that way in order to get the docs for it to show up in the same place as the Spy docs.