Infer object values while strictly specifying keys in TypeScript

ensure-keys.ts

/**
 * TypeScript currently lacks a way of typing a record of keys only but not values.
 * we need this because we want an object of typed keys but we want to leave the values inferred.
 * thankfully, we can do this with generics. This function allows the second generic's values to be inferred
 * so that our object is fully type safe for hugely complex types, but we can guarantee that all the keys we need exist.
 * It's not perfect, but it gets the job done for the time being
 */
export function ensureKeys<T>() {
	/**
	 * Function that returns the value that gets put in, values are type-safely inferred
	 */
	return function <X extends Record<keyof T, unknown>>(data: X) {
		return data;
	};
}