microsoft / microsoft/TypeScript

Custom JSDoc type cannot be extended

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#62,021 7 comments 0 reactions 1 assignee View on GitHub

@sandersn is already working on this.

Since Jul 9, 2025.

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Description

Does this issue occur when all extensions are disabled?: Yes/No

  • VS Code Version: 1.99.3
  • OS Version: Linux x64 6.11.0-24-generic

Steps to Reproduce:

  1. Define a base JSDoc type:
/**
 * @typedef {object} baseType
 * @property {string} baseProperty
 */
  1. Define a child type and add a property:
/**
 * @typedef {baseType} childType
 * @property {string} childProperty
 */

Expected behavior: childType has baseProperty from baseType and childProperty from the own definition.

Actual behavior: childType has only baseProperty from baseType.

However, it works in WebStorm:

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