Add auto-fix for `no-unused-capturing-group`?

[ota-meshi]

Add auto-fix for `no-unused-capturing-group`?

[ota-meshi]

Thank you for posting the issue!

The report may have misused the regular expression, so I think it should be a suggestion instead of an auto-fix.

[fisker]

I'm not by convinced by "misused", is there any case that insert ?: will result differently?

[fisker]

Expect backreferences numbers after it.

[ota-meshi]

For example, the following program is an example of using the wrong index.
This source code needs to shift the index instead of inserting the ?:.

- '2000-12-31'.replace(/(\d{4})-(\d{2})-(\d{2})/, (y, m, d) => `${y}/${m}/${d}`); // "2000-12-31/2000/12"
+ '2000-12-31'.replace(/(\d{4})-(\d{2})-(\d{2})/, (_, y, m, d) => `${y}/${m}/${d}`); // "2000/12/31"

[RunDevelopment]

I'm not by convinced by "misused", is there any case that insert ?: will result differently?
Expect backreferences numbers after it.

Yes.

var replaced = '2000-12-31'.replace(/(\d{4})-(\d{2})-(\d{2})/, '$3') // "2000/12"

But this issue can be solved by only fixing a capturing group if it is the last capturing group in the regex.

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That being said, I also agree with @ota-meshi that unused capturing groups indicate a potential problem. Auto fixes should only be used where it is at least 99% clear what the correct code is. Suggestions are the right tool here IMO.

[fisker]

Cases you mentioned all the same as I said. It will effect groups indexes. At least in .test() if there are no indexed backreferences after the unused group, safe to fix.