fromPartial implementation, attempt #1

fromPartial.ts

import {PartialDeep} from "type-fest";

function fromPartial<T extends {}>(mock: PartialDeep<T>) {
    const proxy = new Proxy(mock, {
        get(target, p, receiver) {
            // If the receiver (the original type) doesn't have it then we ignore it
            if (!(p in receiver)) return undefined
            if (!(p in target)) {
                throw new Error(`${String(p)} not found in mocked object`);
            }
            return Reflect.get(target, p, receiver);
        },
    })
    return proxy as T;
}