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Ruby Example: Prefix second argument

• Playground link

Source

attribute :a, :b, :c, foo, bar

attribute :a, :b, :c, :d

attribute :a, :b

Result

attribute :a, :prefix_b, :c, foo, bar

attribute :a, :prefix_b, :c, :d

attribute :a, :prefix_b

Rule

rule:
  any:
    - pattern: attribute $A, $B, $$$ARGS
    - pattern: attribute $A, $B
fix: attribute $A, $NAME$MAYBE_COMMA$$$ARGS
transform:
  # Idea from https://ast-grep.github.io/guide/rewrite-code.html#add-conditional-text
  MAYBE_COMMA:
    replace:
      by: ', '
      replace: ^.+
      source: $$$ARGS
  NAME:
    replace:
      by: :prefix_$1
      replace: :?(.+)
      source: $B