Microsoft/TypeScript

Class member incorrectly stripped from .d.ts output if @internal is mentioned in unrelated comment

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#57,352 opened on Feb 9, 2024

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 (6 comments) (2 reactions) (0 assignees)TypeScript (6,726 forks)batch import
Domain: Declaration EmitHelp WantedPossible Improvement

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Description

🔎 Search Terms

internal, .d.ts, stripInternal

🕗 Version & Regression Information

This issue appears to be present in all version of TypeScript (tested down to 3.3.3).

⏯ Playground Link

https://www.typescriptlang.org/play?stripInternal=true&ts=5.3.3#code/KYDwDg9gTgLgBAYwDYEMDOa4DEITgbwCg44B6AKnOJPLgGUALCAVyQBM4AjYONGKAJZgwwNtTi0AAgIB2MYFBkok48qWpomrNgCFgdfkJEcAvHACMAbkLVSpOABUA8gBEnALjgBbFAE9u3igA1jwwDAKY0nIKSkgA-LaUqvRa7BIyEDC0AXyCwqKq6iSaLOwAcpl6BnnGcGYATNYAvkA

💻 Code

export class Foo {
  /**
   * Should be stripped
   * @internal
   */
  shouldBeStripped = 1;

  // TODO: maybe make this @internal?
  /**
   * Should *not* be stripped
   */
  shouldNotBeStripped = 2;
}

🙁 Actual behavior

The compiler should preserve the Foo.shouldNotBeStripped property while removing Foo.shouldBeStripped.

🙂 Expected behavior

Both Foo.shouldNotBeStripped and Foo.shouldBeStripped are removed.

Additional information about the issue

If a class member has an unrelated comment mentioning @internal preceding it, TypeScript will drop that member from the .d.ts output, even though that's not the intent since there's another comment after it. Only the first comment should be checked for @internal.

Contributor guide

Research direction
Examine the comment scanning logic in the TypeScript compiler to understand how @internal is detected. Look for where comments are associated with class members and ensure only the last comment preceding a member is considered for @internal.
Tech stack
typescript
Domain
compilers
Issue type
Bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
Half day
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
GitTypeScript
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
60