A function that determines whether a new incoming value should reject or resolve the promise.
A new incoming subscription value.
A truthy value if the promise should be rejected/resolved on this value. Return value is used as the reason in a rejected promise.
A function that determines whether a new incoming value should reject or resolve the promise.
Param
A new incoming subscription value.
Returns
A truthy value if the promise should be rejected/resolved on this value. Return value is used as the reason in a rejected promise.