Function memoize

packages/angular/cli/src/utilities/memoize.ts:16–45

(
  target: (this: This, ...args: Args) => Return,
  context: ClassMemberDecoratorContext,
)

 * @see https://en.wikipedia.org/wiki/Memoization
 */
export function memoize<This, Args extends unknown[], Return>(
  target: (this: This, ...args: Args) => Return,
  context: ClassMemberDecoratorContext,
) {
  if (context.kind !== 'method' && context.kind !== 'getter') {
    throw new Error('Memoize decorator can only be used on methods or get accessors.');
  }

  const cache = new Map<string, Return>();

  return function (this: This, ...args: Args): Return {
    for (const arg of args) {
      if (!isJSONSerializable(arg)) {
        throw new Error(
          `Argument ${isNonPrimitive(arg) ? arg.toString() : arg} is JSON serializable.`,
        );
      }
    }

    const key = JSON.stringify(args);
    if (cache.has(key)) {
      return cache.get(key) as Return;
    }

    const result = target.apply(this, args);
    cache.set(key, result);

    return result;
  };
}

/** Method to check if value is a non primitive. */
function isNonPrimitive(value: unknown): value is object | Function | symbol {