False-positive UselessAssignment when in a slim capture block

[jhubert]

This is a simple recreation of the issue I bumped into with a form_for helper in rails. I'm using capture so that it's distilled down to the essence of the issue:

- url = 'https://google.com'
= capture do
  a href=url = 'Google'

Running slim-lint on this gives me:

test.html.slim:2 [W] RuboCop: Useless assignment to variable - `url`.

[seliverstov-maxim]

up

[yjukaku]

I believe this happens with any method that takes a block, not just capture.

[jclusso]

Any idea on how to fix this. Happy to open a PR with some guidance.

[fvue]

- url = 'https://google1.com'
div data=url

The code above gives warning on line 1: RuboCop: Lint/UselessAssignment: Useless assignment to variable - url.
Whereas the code underneath gives no errors:

- url = 'https://google2.com'
div = url

Workaround is to disable RuboCop: Lint/UselessAssignment in .slim-lint.yml:

# .slim-lint.yml
linters:
  RuboCop:
    enabled: true
    # Disable Lint/UselessAssignment because of false positive, see: https://github.com/sds/slim-lint/issues/68
    # The original 'ignored_cops' list has to be copied in its entirety.
    # For original list, see: https://github.com/sds/slim-lint/blob/main/config/default.yml
    ignored_cops:
      - Layout/ArgumentAlignment
      - Layout/ArrayAlignment
      - Layout/BlockAlignment
      - Layout/ClosingParenthesisIndentation
      - Layout/EmptyLineAfterGuardClause
      - Layout/EndAlignment
      - Layout/FirstArgumentIndentation
      - Layout/FirstArrayElementIndentation
      - Layout/FirstHashElementIndentation
      - Layout/FirstParameterIndentation
      - Layout/HashAlignment
      - Layout/IndentationConsistency
      - Layout/IndentationWidth
      - Layout/InitialIndentation
      - Layout/LineEndStringConcatenationIndentation
      - Layout/LineLength
      - Layout/MultilineArrayBraceLayout
      - Layout/MultilineAssignmentLayout
      - Layout/MultilineHashBraceLayout
      - Layout/MultilineMethodCallBraceLayout
      - Layout/MultilineMethodCallIndentation
      - Layout/MultilineMethodDefinitionBraceLayout
      - Layout/MultilineOperationIndentation
      - Layout/ParameterAlignment
      - Layout/TrailingEmptyLines
      - Layout/TrailingWhitespace
      - Lint/UselessAssignment
      - Lint/Void
      - Metrics/BlockLength
      - Metrics/BlockNesting
      - Naming/FileName
      - Style/FrozenStringLiteralComment
      - Style/IdenticalConditionalBranches
      - Style/IfUnlessModifier
      - Style/Next
      - Style/WhileUntilDo
      - Style/WhileUntilModifier