Deep Set

Requirements

• Export deepSet as named and default. Accept a mutable ordinary object, a dot-delimited string path or an array of string/nonnegative integer segments, and any value. Mutate and return the same root object.
• A string path such as users.0.name is split on dots. Array segments are literal keys, so ["a.b", "value"] does not split a.b. Bracket notation and escaping are outside scope.
• Create an array when the next segment is a canonical nonnegative integer (0 or digits without a leading zero); otherwise create an object. Replace primitive or null intermediate values. Keep existing object/array containers and siblings.
• Traverse own properties only. Never mutate an inherited container. Assign the final value by reference, including undefined.
• Reject empty paths, empty segments, and __proto__, constructor, or prototype anywhere in the path with TypeError before making any change. Numeric segments must be nonnegative integers. Input containers are writable ordinary data objects/arrays; accessors, proxies, functions as containers, and array length paths are outside scope.

Examples

Input: const object = {};
deepSet(object, "users.0.name", "Ada");
object
Output: { users: [{ name: "Ada" }] }

Input: const object = { a: null };
deepSet(object, ["a", "b"], 3);
object
Output: { a: { b: 3 } }