how to handle `Type | boolean` return values in typescript and error checking / tests

I have a function that can return a found object, or fail. What's the best value to return in the failure case? {}|null|undefined|false

The problem is my test rely on this object, but I get typescript warnings as false could also be returned

    const actualResult: ActionResult | boolean = await findAndRunAction(evt)
    if (actualResult) {
      expect(actualResult.klass).toBe('room')

where

function findAndRunAction(): ActionResult | false { 
// if found
return obj: ActionResult
// else
return false
 }

typescript is smart enough to know the value must be truthy but that should be when I am returning an instance of the full object, not just true.

I could throw an error, or the other way would be to always return the same object type but just add a ok: true|false field into the object. That seems a bit excessive, but I guess it does mean I always only have one return type...

Suggestions for good patterns to use with this in TS please!

The compiler fails, but the actual test is passing.

Update: I did something like this:

// define all the other fields as optional

interface ActionResult {
  ok: boolean
  doc?: ActionData
  events?: string[]
  klass?: string
}

// so I can just return an empty obj in fail case

    return {
      ok: false
    }

I don't like this so much as it gives less rigidity on the actual type with all these options.