assoc returns a narrower type than what is passed

[ericyd]

Summary

assoc sometimes returns a more narrow type than what is passed to it. Since assoc never removes props, this feels wrong from a type perspective. I would expect assoc to only add or modify props, never remove.

In the example below, a complex type with 2 props is typed as Record<'flag', bool> after passing through assoc

Dependencies

• ramda@0.29.0
• @types/ramda@0.29.1
• typescript@5.0.2

Example

• Link to codesandbox

import { assoc } from "ramda";

type OriginalType = {
  name: string;
  flag: boolean;
};

function takesAnOriginalType(original: OriginalType) {
  console.log(original);
}

const array: OriginalType[] = [{ name: "test", flag: true }];

const mapped = array.map(assoc("flag", false));

takesAnOriginalType(mapped);
                    ^^^^^^

Error

const mapped: Record<"flag", boolean>[]
Argument of type 'Record<"flag", boolean>[]' is not assignable to parameter of type 'OriginalType'.
  Type 'Record<"flag", boolean>[]' is missing the following properties from type 'OriginalType': name, flagts(2345)

[Harris-Miller]

I've actually been working on this but had yet to push the branch up. I made a draft MR for you: #37

I still have a bunch of testing to do for the different overloads, but it does solve your issue

Using your example: https://tsplay.dev/mqxg2N

[ericyd]

Wow, impressive - fixed the issue before it was even opened!! 👏🏻 👏🏻 👏🏻

Thank you for the diligent and speedy work!

[Harris-Miller]

@ericyd The original MR that I referenced to fix your issue had Breaking changes and I was forced to leave hanging since we're still debating on if we want to merge it or not

Prompted by another issue, I just put up a new MR that is non-breaking but also fixes your issue: #100

Sorry for letting this issue hang for so long

[ericyd]

Wow I just re-read my original bug report and the code snippet I provided is not even an accurate representation of the issue 🤣

Anyway, no worries on the delay. As things go, I was laid off from the job where I used ramda a bunch and now my new company uses lodash 🙄

Thanks for your dedication to this project 🙇🏻 Ramda is great and these types make it even better!