Repeated Specs / Series of Specs

[Dirk Toewe]

Hi everyone,

is there any way to execute a spec for each element in an iterable, without either

1.   blowing up the number of specs or
2.   writing an async spec that uses
   await new Promise( f => sefTimeout(f) )
    to keep the browser responsive?

What I have in mind is something like:

describe('is_even', () => {
  function* even_positive_integers(){
    for( let i=0; i < Number.MAX_SAFE_INTEGER; i+=2 )
      yield i
  }
  for_each_item_in( even_positive_integers() ).it('should return true', item => expect(is_even(item)).toBe(true) )
})

Something like this would be really useful for:

• Exhaustive testing of every combination of inputs/states
• Randomized testing that unveils bugs You haven't even dreamt about.

I already checked the Jasmine docs and the usual suspects and couldn't find anything like that. One simple implementation of the above I can think of is:

const for_each_item_in = items => ({
  it: (specText, specFn) => it(specText, async () => {
    for( const item of items )
    {
      await new Promise( done => setTimeout(done) )
      specFn(item)
    }
  })
})

But the problem with this implementation is that it is impossible to tell for which item in the iterable the failure occoured.

Maybe somebody here knows a better way?

Help would be appreciated

Dirk