docs(@ngrx/signals): add a mention of restructuring withComputed or withMethods for re-use in those features

[michael-small]

Information

The first major stumbling point I had with using features like withComputed or withMethods was the need to reference other computeds or methods in those features. For example, if I wanted a withComputed to expose be able to return a fullName that was a store's firstName and store's lastName, and then also expose a allCapsFullName that was the full name computed inside another computed. But do to what I thought was a limitation of how to return an object like withComputed(({ firstName, lastName }) => ({...}), I had to make a second withComputed

  withComputed(({ firstName, lastName }) => ({
    fullName: computed(() => {
      return `${firstName()} ${lastName()}`;
    }),
  })),
  withComputed(({ fullName }) => ({
    allCapsFullName: computed(() => {
      return fullName().toUpperCase();
    }),
  })),

However, someone pointed out that the first withComputed could be restructured to have a return block, with helper consts or functions.

  withComputed(({ firstName, lastName }) => {
    const fullName = computed(() => {
      return `${firstName()} ${lastName()}`;
    })
    return {
      fullName: fullName,
      allCapsFullName: computed(() => {
        return fullName().toUpperCase();
      }),
    }
  }),

In retrospect this is fairly obvious, but I see the former approach all the time and was stuck in that mindset myself. I think partially because most examples of things like withComputed have those returns without a return block, and because there is a lot of little syntax nuances with functions and objects in the signal store to become comfortable with that add up.

I think something like an FAQ page point on this is warranted with how often this little nuance turns into what is perceived as a bigger problem than it is with an easy solution. Or some examples of the second syntax baked into other pages. Willing to formalize/condense this language to make a PR.

Documentation page

https://ngrx.io/guide/signals/faq

I would be willing to submit a PR to fix this issue

• Yes
• No