curry modifies functions returned from constant

Describe the bug When a constant function is used to return another function, the returned function is automatically curried. This results in the return value no longer matching what was given to constant.

Based on my rough digging, it appears related to the logic of how the curry function works, specifically lines 25-27 in src/core/curry.js. This checks if the value returned by applying the arguments is a function, if it is, it curries the function.

This causes

To Reproduce

import { constant } from 'crocks';

// This is not curried, and should be returned unmodified.
const identity = x => x;

const constantOfIdentity = constant(identity);

// Instead, we see that the returned version is now the definition of the curry function.
console.log(constantOfIdentity().toString());

// This returns false, these are no longer reference equivalent.
console.log(constantOfIdentity() === identity);

Expected behavior The original value given to constant should be returned unmodified.

Additional context This affects any autocurried crocks function that can wind up returning a function itself. I’ve seen the same behavior with ifElse and when.

[evilsoft]

@goulderb yeah, I was afraid you were going to say tcomb or something to do with specs/tests. It was because of tcomb, that we started adding things like isSameType and a lot of the type predicates. I would recommend doing what you have been for now. We have been thinking of ways we can answer this issue of equality vs equivalence and do not have an answer yet.

But as soon as we do, we will be sure to broadcast it to the world.

[dalefrancis88]

Closing this for now as it seems resolved. Feel free to re-open if there is more to discuss