🐛 noUnusedVariables incorrectly flags types, possible improvements

[nstepien]

Environment information

CLI:
  Version:              10.0.1
  Color support:        true

Platform:
  CPU Architecture:     x86_64
  OS:                   windows

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  ROME_LOG_DIR:         unset
  NO_COLOR:             unset
  TERM:                 unset

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  Linter disabled:      false

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What happened?

interface Props {
  fn: ({ a, b }: { a: number; b: string }) => void;
}

try {
  fn();
} catch (error) {
  log();
}

.\test.tsx:2:10 lint/correctness/noUnusedVariables  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! This variable is unused.

    1 │ interface Props {
  > 2 │   fn: ({ a, b }: { a: number; b: string }) => void;
      │          ^
    3 │ }
    4 │ 

  i Unused variables usually are result of incomplete refactoring, typos and other source of bugs.

  i Suggested fix: If this is intentional, prepend a with an underscore.

     1  1 │   interface Props {
     2    │ - ··fn:·({·a,·b·}:·{·a:·number;·b:·string·})·=>·void;
        2 │ + ··fn:·({·_a,·b·}:·{·a:·number;·b:·string·})·=>·void;
     3  3 │   }
     4  4 │ 


.\test.tsx:2:13 lint/correctness/noUnusedVariables  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! This variable is unused.
  
    1 │ interface Props {
  > 2 │   fn: ({ a, b }: { a: number; b: string }) => void;
      │             ^
    3 │ }
    4 │ 

  i Unused variables usually are result of incomplete refactoring, typos and other source of bugs.

  i Suggested fix: If this is intentional, prepend b with an underscore.

     1  1 │   interface Props {
     2    │ - ··fn:·({·a,·b·}:·{·a:·number;·b:·string·})·=>·void;
        2 │ + ··fn:·({·a,·_b·}:·{·a:·number;·b:·string·})·=>·void;
     3  3 │   }
     4  4 │ 


.\test.tsx:7:10 lint/correctness/noUnusedVariables  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! This variable is unused.

    5 │ try {
    6 │   fn();
  > 7 │ } catch (error) {
      │          ^^^^^
    8 │   log();
    9 │ }

  i Unused variables usually are result of incomplete refactoring, typos and other source of bugs.

  i Suggested fix: If this is intentional, prepend error with an underscore.

     5  5 │   try {
     6  6 │     fn();
     7    │ - }·catch·(error)·{
        7 │ + }·catch·(_error)·{
     8  8 │     log();
     9  9 │   }

Expected result

In the interface, a and b are flagged as unused, the rule is suggesting to prefix them with _ which would give invalid types.

In catch (error), instead of prefixing error with an underscore, we can just omit it.

So Rome could give better suggestions so the code can end up like this:

interface Props {
  fn: (arg1: { a: number; b: string }) => void;
}

try {
  fn();
} catch {
  log();
}

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