audit: Port audit_conflicts method to rubocop and add tests

2 files changed, 37 insertions, 0 deletions

diff --git a/Library/Homebrew/rubocops/conflicts_cop.rb b/Library/Homebrew/rubocops/conflicts_cop.rb
new file mode 100644
index 000000000..c1b801559
--- /dev/null
+++ b/Library/Homebrew/rubocops/conflicts_cop.rb
@@ -0,0 +1,27 @@
+require_relative "./extend/formula_cop"
+require_relative "../extend/string"
+
+module RuboCop
+  module Cop
+    module FormulaAudit
+      # This cop audits versioned Formulae for `conflicts_with`
+      class Conflicts < FormulaCop
+        MSG = <<-EOS.undent
+          Versioned formulae should not use `conflicts_with`.
+          Use `keg_only :versioned_formula` instead.
+        EOS
+
+        WHITELIST = %w[
+          node@
+          bash-completion@
+        ].freeze
+
+        def audit_formula(_node, _class_node, _parent_class_node, body)
+          return unless versioned_formula?
+          problem MSG if !formula_file_name.start_with?(*WHITELIST) &&
+                         method_called_ever?(body, :conflicts_with)
+        end
+      end
+    end
+  end
+end
diff --git a/Library/Homebrew/rubocops/extend/formula_cop.rb b/Library/Homebrew/rubocops/extend/formula_cop.rb
index 439fde6a5..ddfb507d2 100644
--- a/Library/Homebrew/rubocops/extend/formula_cop.rb
+++ b/Library/Homebrew/rubocops/extend/formula_cop.rb
@@ -344,6 +344,16 @@ module RuboCop
         end
       end
 
+      # Returns true if the formula is versioned
+      def versioned_formula?
+        formula_file_name.include?("@") || @formula_name.match(/AT\d+/)
+      end
+
+      # Returns filename of the formula without the extension
+      def formula_file_name
+        File.basename(processed_source.buffer.name, ".rb")
+      end
+
       # Returns printable component name
       def format_component(component_node)
         return component_node.method_name if component_node.send_type? || component_node.block_type?