Warn when JSDoc type cast misses parentheses

Search Terms

jsdoc. type cast

Suggestion

JSDoc type cast currently requires parentheses for technical reasons (#18212), but it does not warn when they don't exist.

Use Cases

// This doesn't work, the JSDoc comment is silently ignored
// A warning message will help.
const img = /** @type {HTMLImageElement} */ document.getElementById('#cat')
img.src = 'cat.gif'

Examples

const img = /** @type {HTMLImageElement} */ document.getElementById('#cat')
            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
            ^ Warning: The JSDoc type cast misses parentheses and is being ignored
img.src = 'cat.gif'

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.

Commencez par le traitement des conversions de type JSDoc décrit dans l’issue et dans l’issue référencée #18212, puis localisez le diagnostic et les tests de régression associés. La modification est terminée lorsqu’une conversion de type sans parenthèses produit l’avertissement indiqué sans modifier la sortie JavaScript, tandis que les conversions de type entre parenthèses conservent leur comportement actuel.