Microsoft/TypeScript

API: incorrect declarations in types.ts

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#24,706 opened on Jun 5, 2018

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 (5 comments) (12 reactions) (0 assignees)TypeScript (48,455 stars) (6,726 forks)batch import
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Description

The --strictNullChecks PR changed some declarations in types.ts to avoid frequent assertions in the compiler's code. Unfortunately these changes make it really unsafe for API users because they no longer contain the actually nullable types: https://github.com/Microsoft/TypeScript/pull/22088#discussion_r184149465 https://github.com/Microsoft/TypeScript/pull/22088#discussion_r184155027

  • ts.Node#parent is no longer optional (which is definitely wrong for SourceFile)
  • ts.Symbol#declarations and ts.Symbol.valueDeclaration are no longer optional, but can still be undefined
  • ts.Type#symbol is no longer optional, but I guess this comment is still up to date: // Symbol associated with type (if any)

These changes should either be reverted or replaced in the published declaration files. /cc @andy-ms @weswigham

Contributor guide

Tech stack
typescript
Domain
api
Issue type
bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
4
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-2 days
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
TypeScript strictNullChecksTypeScript compiler internalsType declaration files (.d.ts)Git and GitHub workflow
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
25
Research direction
Review the PR #22088 and the specific discussions referenced (discussion r184149465, discussion r184155027). Examine the current types.ts in the TypeScript compiler to identify the declarations for Node.parent, Symbol.declarations, Symbol.valueDeclaration, and Type.symbol. Determine whether to revert the changes or add proper optionality. Check for any follow up comments or maintainer guidance. Propose a fix that ensures type safety while maintaining API compatibility.
API: incorrect declarations in types.ts · Microsoft/TypeScript#24706 | Good First Issue