Rule proposal: prefer-optional-catch-binding

Please describe what the rule should do:

This rule reports and fixes unused catch bindings.

try {
    f()
} catch (err) { // unused!
    g()
}

We can modify such code safely to simple:

try {
    f()
} catch {
    g()
}

What category of rule is this? (place an “X” next to just one item)

[X] Enforces code style [ ] Warns about a potential error [ ] Suggests an alternate way of doing something [ ] Other (please specify:)

Provide 2-3 code examples that this rule will warn about:

//✗ BAD
try {
    f()
} catch (err) { // unused!
    g()
}

//✓ GOOD
try {
    f()
} catch (err) {
    g(err)
}

try {
    f()
} catch {
    g()
}

Why should this rule be included in ESLint (instead of a plugin)?

This rule will encourage to use new syntax in ES2019. It makes more readable to remove unused variables. The autofix is useful.

[ljharb]

I’d love to see this reopened and revisited.

[eslint-deprecated[bot]]

Unfortunately, it looks like there wasn’t enough interest from the team or community to implement this change. While we wish we’d be able to accommodate everyone’s requests, we do need to prioritize. We’ve found that issues failing to reach accepted status after 21 days tend to never be accepted, and as such, we close those issues. This doesn’t mean the idea isn’t interesting or useful, just that it’s not something the team can commit to.

Thanks for contributing to ESLint and we appreciate your understanding.