| import type { DeepReadonly } from './deep-readonly' | |
| /** | |
| * Recursively freezes an object and all of its properties. This prevents the | |
| * object from being modified at runtime. When the JS runtime is running in | |
| * strict mode, any attempts to modify a frozen object will throw an error. | |
| * | |
| * @see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/freeze | |
| * @param obj The object to freeze. | |
| */ | |
| export function deepFreeze<T extends object>(obj: T): DeepReadonly<T> { | |
| // If the object is already frozen, there's no need to freeze it again. | |
| if (Object.isFrozen(obj)) return obj as DeepReadonly<T> | |
| // An array is an object, but we also want to freeze each element in the array | |
| // as well. | |
| if (Array.isArray(obj)) { | |
| for (const item of obj) { | |
| if (!item || typeof item !== 'object') continue | |
| deepFreeze(item) | |
| } | |
| return Object.freeze(obj) as DeepReadonly<T> | |
| } | |
| for (const value of Object.values(obj)) { | |
| if (!value || typeof value !== 'object') continue | |
| deepFreeze(value) | |
| } | |
| return Object.freeze(obj) as DeepReadonly<T> | |
| } | |