microsoft / microsoft/TypeScript
Mixing Iterable destruction with plain args when calling function
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Nobody has claimed this yet.
Bug
Domain: check: Type Inference
- Dominant language
- Go
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- Forks
- 14.3k
- Avg merge
- 2d 4h
- Merged PRs (30d)
- 132
Description
Bug Report
🔎 Search Terms
🕗 Version & Regression Information
- This changed between versions 3.3.3333 and 3.5.1
⏯ Playground Link
Playground link with relevant code
💻 Code
// no errors, wrong
new Set(...new Set<string>([]), '34')
new Set(...new Set<string>(['12']), '34')
// error, ok
new Set('12', '34')
🙁 Actual behavior
Code accepted as valid
🙂 Expected behavior
Error thrown
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Start with the linked TypeScript Playground and reproduce the two accepted new Set(...new Set<string>(...), '34') calls alongside the rejected plain-argument case. Trace the checker entry point for constructor calls with iterable spreads, then add a regression test covering the reported forms and verify that invalid calls are rejected.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- typescript
- Domain
- compilers
- Issue type
- Bug
- Difficulty
- 3/5
- Estimated time
- 1-2 days
- Activity status
- Stale
- Clarity
- Clearly specified
- Newbie friendliness
- 38/100