Superfluous type operation parentheses are not stripped
Open
Nobody has claimed this yet.
area:union types
lang:typescript
status:needs discussion
- Dominant language
- JavaScript
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Description
I expected type operation parens stripping would work like the one for regular JS operations, i.e. superfluous parens would be removed. That seems to not be the case. Now I am wondering: is that by design?
Prettier 2.7.1
Playground link
--parser babel
Input:
type T = (1 | 1) | 2;
Output:
type T = (1 | 1) | 2;
Expected behavior:
type T = 1 | 1 | 2;
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
Reproduce the issue in the Prettier Playground with the babel parser using the provided JSX input. Trace how type-operation parentheses are printed, then add or update a regression test so the output removes only the superfluous outer parentheses and matches the expected formatting.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- javascript
- Domain
- tooling
- Issue type
- Bug
- Difficulty
- 3/5
- Estimated time
- 1-2 days
- Activity status
- Stale
- Clarity
- Clearly specified
- Newbie friendliness
- 45/100