Contents

require 'set'
require 'reek/smells/smell_detector'
require 'reek/smell_warning'

module Reek
  module Smells
    #
    # Class variables form part of the global runtime state, and as such make
    # it easy for one part of the system to accidentally or inadvertently
    # depend on another part of the system. So the system becomes more prone to
    # problems where changing something over here breaks something over there.
    # In particular, class variables can make it hard to set up tests (because
    # the context of the test includes all global state).
    #
    class ClassVariable < SmellDetector
      SMELL_CLASS = name.split(/::/)[-1]
      SMELL_SUBCLASS = SMELL_CLASS

      VARIABLE_KEY = 'variable'

      def self.contexts      # :nodoc:
        [:class, :module]
      end

      #
      # Checks whether the given class or module declares any class variables.
      #
      # @return [Array<SmellWarning>]
      #
      def examine_context(ctx)
        class_variables_in(ctx.exp).map do |attr_name, lines|
          attr_name = attr_name.to_s
          smell = SmellWarning.new(SMELL_CLASS, ctx.full_name, lines,
                                   "declares the class variable #{attr_name}",
                                   @source, SMELL_SUBCLASS,
                                   VARIABLE_KEY => attr_name)
          smell
        end
      end

      #
      # Collects the names of the class variables declared and/or used
      # in the given module.
      #
      def class_variables_in(ast)
        result = Hash.new { |hash, key| hash[key] = [] }
        collector = proc do |cvar_node|
          result[cvar_node.name].push(cvar_node.line)
        end
        [:cvar, :cvasgn, :cvdecl].each do |stmt_type|
          ast.each_node(stmt_type, [:class, :module], &collector)
        end
        result
      end
    end
  end
end

Version data entries

3 entries across 3 versions & 1 rubygems

Version	Path
reek-1.5.1	lib/reek/smells/class_variable.rb
reek-1.5.0	lib/reek/smells/class_variable.rb
reek-1.4.0	lib/reek/smells/class_variable.rb