microsoft / microsoft/TypeScript

In JS, `object` is treated as 'any'

Open
#25,624 11 comments 4 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

Awaiting More Feedback checkJs Domain: JavaScript Domain: JSDoc Suggestion
Dominant language
Go
Stars
111k
Forks
14.3k
Avg merge
2d 4h
Merged PRs (30d)
132

Description

TypeScript Version: 3.0.0-dev.20180711

Code

/** @typedef {object} T */
/** @type {T} */
const x = 0;

Expected behavior:

Error at x: 0 is not an object.

Actual behavior:

No error.

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start by reproducing the TypeScript Version 3.0.0-dev.20180711 example with the JSDoc @typedef and @type annotations shown in the issue. Trace the JavaScript checking path for object types and compare the reported result with the expected error at x. Done means the example reports that 0 is not an object, with tests covering this behavior.

Written by the indexing model from the issue text.

Assessment

Tech stack
javascript, typescript
Domain
compilers
Issue type
Bug
Difficulty
3/5
Estimated time
1-2 days
Activity status
Quiet
Clarity
Clearly specified
Newbie friendliness
52/100

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.