feat(typescript-types): Add Get<O, P>

packages/typescript-types/src/get.ts

@@ -0,0 +1,25 @@
+import type { If } from './if.js'
+import type { KeyPath } from './key-path.js'
+import type { KeyPaths } from './key-paths.js'
+
+type FilterUndefined<T> = T extends undefined ? never : T
+type FilterNull<T> = T extends null ? never : T
+type FilterUndefinedAndNull<T> = FilterUndefined<FilterNull<T>>
+
+type ExtractFromForKey<Obj, Key, Rest> = Key extends keyof Obj
+	? Obj[Key] extends Record<PropertyKey, unknown>
+		? GetByKeyPath<Obj[Key], Rest>
+		: Obj[Key]
+	: Key extends keyof FilterUndefinedAndNull<Obj>
+		? FilterUndefinedAndNull<Obj>[Key] | undefined
+		: undefined
+
+type HasNoMoreKeys<K> = K extends [] ? true : false
+
+type GetByKeyPath<Obj, Keys> = If<
+	HasNoMoreKeys<Keys>,
+	Obj,
+	Keys extends [infer Key, ...infer Rest] ? ExtractFromForKey<Obj, Key, Rest> : never
+>
+
+export type Get<O extends object, P extends KeyPaths<O>> = GetByKeyPath<O, KeyPath<P>>