Closed
Description
Before You File a Proposal Please Confirm You Have Done The Following...
- I have searched for related issues and found none that match my proposal.
- I have searched the current rule list and found no rules that match my proposal.
- I have read the FAQ and my problem is not listed.
My proposal is suitable for this project
- My proposal specifically checks TypeScript syntax, or it proposes a check that requires type information to be accurate.
- My proposal is not a "formatting rule"; meaning it does not just enforce how code is formatted (whitespace, brace placement, etc).
- I believe my proposal would be useful to the broader TypeScript community (meaning it is not a niche proposal).
Description
When a function parameter (or a class property) is marked as optional with ?
, it implicitly includes undefined
in the type definition, so there is no need to explicitly add an | undefined
to the type definition. I'd like to detect these cases and also autofix away the | undefined
.
I don't think I see an existing rule to do this and it seems too complicated to do with no-restricted-syntax
(though it wouldn't be able to autofix anyways).
Fail Cases
function foo(bar?: number | undefined) {
return bar
}
Pass Cases
function foo(bar?: number) {
return bar
}
Additional Info
No response