microsoft / microsoft/TypeScript

Should not allow `import.defer?.('x')`

Open
#63,679 4 comments 0 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

Bug Domain: Parser Help Wanted
Dominant language
Go
Stars
111k
Forks
14.3k
Avg merge
2d 4h
Merged PRs (30d)
132

Description

🔎 Search Terms

"import defer"

🕗 Version & Regression Information
  • This changed between versions ______ and _______
  • This changed in commit or PR _______
  • This is the behavior in every version I tried, and I reviewed the FAQ for entries about 6.0.3_____
  • I was unable to test this on prior versions because _______
⏯ Playground Link

https://www.typescriptlang.org/play/?moduleResolution=99&target=99&ssl=3&ssc=40&pln=2&pc=1#code/JYWwDg9gTgLgBPAZlCI4HIYE8wFMDOAxlMGDOgNwBQVhEAdvvGHALxyiSwB0AJrolxQA-NwAUmHAWKlyASgpA

💻 Code
import.defer?.('x');
🙁 Actual behavior

No errors.

🙂 Expected behavior

Should not allow it as an optional call.

Additional information about the issue

Parsers like Oxc, Yuku, SWC, Babel all reject it. I didn't read the spec, but unless they are wrong.

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 with the provided TypeScript Playground link and the import.defer?.('x') example to reproduce the parser behavior. Trace the parser entry point for import-defer syntax and compare the handling with the rejecting behavior reported for Oxc, Yuku, SWC, and Babel. Done means this code is rejected rather than accepted as an optional call, with a regression test covering it.

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
Active
Clarity
Clearly specified
Newbie friendliness
70/100

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.