duplicate comments on decorated fields

🔎 Search Terms

typescript duplicate comments

🕗 Version & Regression Information

• This changed between versions ______ and _______
• This changed in commit or PR _______
• This is the behavior in every version I tried, and I reviewed the FAQ for entries about _________
• I was unable to test this on prior versions because _______

⏯ Playground Link

https://www.typescriptlang.org/play/?target=9&ts=5.5.0-beta#code/MYGwhgzhAEDKAWYBOBTAJgQQAoEloG8BfAKGJQA8AHAeyQBdpRIZZgUA7FaCujtFxKky4CxAJAB6AFRTx0KdAAClJNUop6ATwIAjatRAow7QtADuKHQHMQ0ALRypE8Yr0Gj7DHTpIAljoBXXnNLG2gAXmgAMzAQCBRiaGhpWTF5JRU1DTptfDdDY1Mo-XtHZzFXfQLPbz9A4OLqCOjY+OISIA

💻 Code

class SharedAPI {}

export class Scene extends SharedAPI {
	/**
	 * @property {boolean} webgl -
	 */
	@booleanAttribute webgl = false
  /**
	 * @property {boolean} foo -
	 */
	@booleanAttribute foo = false
}

🙁 Actual behavior

duplicate comments for the foo property appear in output

🙂 Expected behavior

No duplicate comments

Additional information about the issue

The output shows this:

        constructor() {
            super(...arguments);
            /**
             * @property {boolean} webgl -
             */
            this.webgl = __runInitializers(this, _webgl_initializers, false
            /**
               * @property {boolean} foo -
               */
            );
            /**
               * @property {boolean} foo -
               */
            this.foo = (__runInitializers(this, _webgl_extraInitializers), __runInitializers(this, _foo_initializers, false));
            __runInitializers(this, _foo_extraInitializers);
        }

There's an extra @property {boolean} foo - comment in the output.

Similar issue:

• https://github.com/microsoft/TypeScript/issues/45696

Start with the linked TypeScript Playground repro using target ES2022 and TypeScript 5.5.0-beta, then compare the emitted JavaScript for the decorated webgl and foo fields. The change is done when the foo property's JSDoc comment appears only once while the expected decorator initialization output remains intact.