JSDoc comments emitted a second time even after commenrs on type are emitted

🔎 Search Terms

JSDoc, emit, comments

🕗 Version & Regression Information

v5.9.2

• I was unable to test this on prior versions because I was not using TS.

⏯ Playground Link

No response

💻 Code

/**
 * The template passed to generate messages
 *
 * @callback Template
 * @param {...*} args - Arguments to the template
 * @returns {any} The generated message
 */

/**
 * The arguments sent with notify become the input parameters for the template.
 *
 * @typedef {Parameters<Template>} TemplateParams
 */

/**
 * The return value from the template is yielded as the message generated from
 * the subscription. The following types help define this relationship.
 *
 * @typedef {ReturnType<Template>} Message
 */

🙁 Actual behavior

Typescript, when emitting from JSDoc, seems to want to emit the same comments for a type declaration twice:

• once for the export (good) and
• once just copying over the JSDoc comment (bad).

/**
 * The template passed to generate messages
 */
export type Template = (...args: any[]) => any;
/**
 * The arguments sent with notify become the input parameters for the template.
 */
export type TemplateParams = Parameters<Template>;
/**
 * The return value from the template is yielded as the message generated from
 * the subscription. The following types help define this relationship.
 */
export type Message = ReturnType<Template>;
/**
 * The template passed to generate messages
 *
 * @callback Template
 * @param {...*} args Arguments to the template
 * @returns {any} The generated message
 */
/**
 * The arguments sent with notify become the input parameters for the template.
 *
 * @typedef {Parameters<Template>} TemplateParams
 */
/**
 * The return value from the template is yielded as the message generated from
 * the subscription. The following types help define this relationship.
 *
 * @typedef {ReturnType<Template>} Message
 */

🙂 Expected behavior

It should emit the comment just once:

/**
 * The template passed to generate messages
 */
export type Template = (...args: any[]) => any;
/**
 * The arguments sent with notify become the input parameters for the template.
 */
export type TemplateParams = Parameters<Template>;
/**
 * The return value from the template is yielded as the message generated from
 * the subscription. The following types help define this relationship.
 */
export type Message = ReturnType<Template>;

or even better (See #61664)

/**
 * The template passed to generate messages
 *
 * @param Arguments to the template
 * @returns The generated message
 */
export type Template = (...args: any[]) => any;
/**
 * The arguments sent with notify become the input parameters for the template.
 */
export type TemplateParams = Parameters<Template>;
/**
 * The return value from the template is yielded as the message generated from
 * the subscription. The following types help define this relationship.
 */
export type Message = ReturnType<Template>;

Additional information about the issue

No response

TypeScript v5.9.2 を使い、提供された JavaScript/JSDoc スニペットで報告を再現してから、重複したコメントの原因となっている宣言出力パスを追跡します。生成された宣言に対するリグレッションテストを追加し、関連する #61664 の挙動を確認しながら、各コメントが1回だけ現れることを検証します。