typescript utility types

type RequiredKeys<T> = Exclude<
	{
		[K in keyof T]: Extract<T[K], undefined> extends never ? K : never;
	}[keyof T],
	undefined
>;

type OptionalKeys<T> = Exclude<
	{
		[K in keyof T]: Extract<T[K], undefined> extends never ? never : K;
	}[keyof T],
	undefined
>;

type PickRequired<T> = Pick<T, RequiredKeys<T>>;

type PickOptional<T> = Pick<T, OptionalKeys<T>>;

type Nullable<T> = { [P in keyof T]: T[P] | null };

type NullableOptional<T> = PickRequired<T> & Nullable<PickOptional<T>>;

type DeepNullable<T> = { [K in keyof T]: DeepNullable<T[K]> | null };

type RequireAtLeastOne<T, Keys extends keyof T = keyof T> = Pick<T, Exclude<keyof T, Keys>> &
	{
		[K in Keys]-?: Required<Pick<T, K>> & Partial<Pick<T, Exclude<Keys, K>>>;
	}[Keys];

type CamelCase<S> = S extends `ID` ? `id` : S extends string ? Uncapitalize<S> : S;

type CamelCased<T> = T extends any[]
	? { [K in keyof T]: CamelCased<T[K]> }
	: T extends Record<string, any>
		? { [K in keyof T as CamelCase<K>]: CamelCased<T[K]> }
		: T;