Allow usage of `Reflect.get()` by returning `unknown` instead of `any`

Search Terms

Reflect get unknown

Suggestion

Change the type definition of Reflect.get() to return unknown instead of any.

Use Cases

Allow type safe dynamic access of fields on an object or { [k: string}: unknown }

Using Reflect.get(o, 'some key') and have it return unknown.

This allows usage of Reflect.get() in code bases where we do not want implicit any and where we have @typescript-eslint rules to ban unsafe usage of any.

Examples

/**
 * @param {CustomError} cause
 * @returns {{ [k: string]: unknown }}
 */
function getInfoForPlainError (cause) {
  /** @type {{ [k: string]: unknown }} */
  const info = {}
  for (const field of PLAIN_ERROR_FIELDS) {
    const v = reflectGet(cause, field)
    if (typeof v !== 'undefined') {
      info[field] = v
    }
  }
  return info
}

Checklist

My suggestion meets these guidelines:

• This wouldn't be a breaking change in existing TypeScript/JavaScript code
• This wouldn't change the runtime behavior of existing JavaScript code
• This could be implemented without emitting different JS based on the types of the expressions
• This isn't a runtime feature (e.g. library functionality, non-ECMAScript syntax with JavaScript output, etc.)
• This feature would agree with the rest of TypeScript's Design Goals.

Unfortunately changing a signature from any to unknown is a breaking change.

Commencez par localiser la déclaration de lib.d.ts pour Reflect.get et les tests qui couvrent son type de retour inféré. Vérifiez comment le remplacement de any par unknown affecte les attentes existantes en matière de vérification des types ; c'est terminé lorsque la déclaration et les tests concernés prennent systématiquement en charge le type de retour demandé.