Add support for the ownKeys trap

[luisherranz]

What

Add support for the ownKeys trap, which is used with for..in, getOwnPropertyNames or Object.keys/values/entries.

• I also exported the RevertDeepSignal type which is useful when using Object.values().
• I also added some missing tests for similar array subscriptions, although those where working fine because they access array.length and we were already updating that signal when items are added or removed from the array.

Why

To be able to subscribe when properties are added or removed from objects.

const store = deepSignal({ a: 1 });

effect(() => {
  for (const key in store) {
    console.log(`${key}: ${store[key]}`);
  }
});

store.b = 2; // console.logs `a: 1` and `b: 2`

How

I added a new map that stores a fake signal for each object. When ownKeys is accessed, the computations are subscribed to that signal. When a property is added or removed from the object, we update the signal to retrigger the subscribed computations.

[github-actions]

Size Change: +343 B (+6%) 🔍

Total Size: 6.1 kB

Filename	Size	Change
packages/deepsignal/core/dist/deepsignal-core.js	994 B	+55 B (+6%)	🔍
packages/deepsignal/core/dist/deepsignal-core.mjs	985 B	+62 B (+7%)	🔍
packages/deepsignal/dist/deepsignal.js	1.03 kB	+56 B (+6%)	🔍
packages/deepsignal/dist/deepsignal.mjs	1.03 kB	+56 B (+6%)	🔍
packages/deepsignal/react/dist/deepsignal-react.js	1.03 kB	+58 B (+6%)	🔍
packages/deepsignal/react/dist/deepsignal-react.mjs	1.03 kB	+56 B (+6%)	🔍

_{compressed-size-action}

[luisherranz]

@DAreRodz, sorry to bother you again, but if you could take a look here, it would be fantastic. Many thanks 🙂

[rozek]

Congratulations!

Looks much more elegant than my quick hack from yesterday!

However: would you ming adding support for Object.defineProperty(...) as well? To my current understanding, simply trapping set does not cover all possibilities to add a new property to an object...

[luisherranz]

However: would you ming adding support for Object.defineProperty(...) as well? To my current understanding, simply trapping set does not cover all possibilities to add a new property to an object...

Can you open another issue for that and explain the use cases, etc? Thanks!

[DAreRodz]

LGTM! 👍 It's no bother at all, @luisherranz. 😄