Microsoft/TypeScript

Double slash comment `//` will be wrongly removed in the trailing position of the object attribute

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#56,055 opened on Oct 10, 2023

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

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Description

🔎 Search Terms

  • comment removal
  • removeComments

🕗 Version & Regression Information

  • This is the behavior in every version I tried.

⏯ Playground Link

https://www.typescriptlang.org/play?ts=5.2.2#code/KYDwDg9gTgLgBAYwgOwM7wGYQnAvHAbwCg5S4sIAuOAcgpoBo4B6ZuGACwEtVEIBbfsGTwA7lwA2EuACNgcKMH4QAbsAAmAOhJkZAQyjUa+qDRZtOPPoOFjJ0uXADWwMDCYyArmI4BPbQC+QA

💻 Code

export const foo = {
    foo: 'foo', // this comment will be removed, however this should be kept
    bar: 'bar' // this comment will be kept, works well
}

🙁 Actual behavior

export const foo = {
    foo: 'foo',
    bar: 'bar' // this comment will be kept, works well
}

🙂 Expected behavior

export const foo = {
    foo: 'foo', // this comment will be removed, however this should be kept
    bar: 'bar' // this comment will be kept, works well
}

Additional information about the issue

No response

Contributor guide

Research direction
Investigate the comment removal logic in the TypeScript compiler, focusing on object literal property declarations. The bug removes a trailing comment after a comma when it should be preserved. Look at the scanner or transformer responsible for removing comments.
Tech stack
typescript
Domain
tooling
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.
1-3 hours
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.
70