Function makeReadOnly

compiler/packages/make-read-only-util/src/makeReadOnly.ts:91–148

(o: T, source: string)

  // Changes an object to be read-only, returns its input
  function makeReadOnly<T>(o: T, source: string): T {
    if (typeof o !== 'object' || o == null) {
      return o;
    } else if (
      o.constructor?.name != null &&
      skippedClasses.includes(o.constructor.name)
    ) {
      return o;
    }

    const {existed, entry: cache} = getOrInsertDefault(savedROObjects, o);

    for (const [k, entry] of cache.entries()) {
      const currentProp = Object.getOwnPropertyDescriptor(o, k);
      if (currentProp && !isWriteable(currentProp)) {
        continue;
      }
      const currentPropGetter = currentProp?.get;
      const cachedGetter = entry.getter;

      if (currentPropGetter !== cachedGetter) {
        // cache is currently holding an old property
        //  - it may have been deleted
        //  - it may have been deleted + re-set
        //    (meaning that new value is not proxied,
        //     and the current proxied value is stale)
        cache.delete(k);
        if (!currentProp) {
          logger('FORGET_DELETE_PROP_IMMUT', source, k);
        } else if (currentProp) {
          logger('FORGET_CHANGE_PROP_IMMUT', source, k);
          addProperty(o, source, k, currentProp, cache);
        }
      }
    }
    for (const [k, prop] of Object.entries(
      Object.getOwnPropertyDescriptors(o),
    )) {
      if (!cache.has(k) && isWriteable(prop)) {
        if (
          prop.hasOwnProperty('set') ||
          prop.hasOwnProperty('get') ||
          k === 'current'
        ) {
          // - we currently don't handle accessor properties
          // - we currently have no other way of checking whether an object
          // is a `ref` (i.e. returned by useRef).
          continue;
        }

        if (existed) {
          logger('FORGET_ADD_PROP_IMMUT', source, k);
        }
        addProperty(o, source, k, prop, cache);
      }
    }
    return o;
  }