[thih9]

About pain points / feature requests:

Is there an idiomatic way to duplicate a hash while replacing one of its values, preferably something that supports nesting?

Whenever I work with react and immutable structures, this comes up and I hack something simple.

I don’t do FE on a regular basis though so my perspective may be skewed.

[sethaurus]

These days that's pretty well-supported in the base language:

    const updated = { ...existing, someKey: someNewValue };

You mention nesting. That starts to look messier:

    const updated = { ...existing, someKey: { ...existing.someKey, ...someNewValue } };

There's a whole cottage industry of little libraries to make this ergonomic/fast in the general case (copying immutable objects with nested changes). `immer` is a popular choice. But the reality is that it gets complicated to do this generically; in my view it's usually better to just use the base language where possible, even if it means sprouting some util functions for the various kinds of updates you end up doing.

[antifa]

There might be a function called produce in one of your immutable/react lib.