SolidJS•2y ago

How to check if a variable is a solid-Mutable or -Store?

Is there a way how you can detect if a variable is a createMutable/Store-proxy? It is for the purpose of working with another library's proxies.

6 Replies

fabiospampinato•2y ago

I think the only way is to add some property to it and see if it throws

bigmistqkeOP•2y ago

import { DEV } from 'solid-js/store';
DEV?.isWrappable(x) === true

import { DEV } from 'solid-js/store';
DEV?.isWrappable(x) === true

would this be okay? it warns me that DEV can also be undefined

thetarnav•2y ago

you can use the $PROXY symbol to check if it's a proxy at all DEV is not available in prod

bigmistqkeOP•2y ago

you just call it like an object? state[$PROXY]? ok nice that seems to do the trick!

fabiospampinato•2y ago

const isMutable = store => {
  if ( !store[$PROXY] ) return false; // Not a store at all
  const symbol = Symbol ();
  try {
    store[symbol] = true;
    delete store[symbol];
    return true; // A mutable store
  } catch {
    return false; // A regular store
  }
};

const isMutable = store => {
  if ( !store[$PROXY] ) return false; // Not a store at all
  const symbol = Symbol ();
  try {
    store[symbol] = true;
    delete store[symbol];
    return true; // A mutable store
  } catch {
    return false; // A regular store
  }
};

bigmistqkeOP•2y ago

oo nice, it's for interop with another library, so for my usecase rn it doesn't matter too much if it's a store or a mutable, but good to know

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How to check if a variable is a solid-Mutable or -Store?