Assert, getter function always fail with expecting a property

For the reproduction shake only assert.decreasesBy. See reproduction, line 16 pass; 18, 19 both fail.

AssertionError: 1: expected [Function: fn] to have property ‘x’

But i suspecting:

• assert.decreasesButNotBy
• assert.increasesBy
• assert.increasesButNotBy

When use getter function, let me know if i am wrong. Discovered when made #1085 to aim #1084.

[sukrosono]

Assign me Cap, working on it.

I have a question, the 3rd param was written optional but when we use the getterFn i feel like need to have the 3rd param. Then here still need 4th param delta. I found it awkward when we use assert(fn, getterFn, null, 1) for example. The 3rd param property as optional also found on several function, any advice?

[lucasfcosta]

Since me and @keithamus are cleaning up issues I’ll close this because it will go into the roadmap.

As I demonstrated before, asserting on properties of functions is a valid use case.

I also mentioned that we can actually see if users did pass a property name or not by checking the number of arguments. If users pass 3 arguments then it means the third one is a value, not a property name (after all decreasesBy implies you will have to pass an argument which tells the delta). So this is what we’re going to do.