Rubocop between-cop interdependencies

README.md

I wrote quick&dirty script to see the dependencies between cops (i.e. when a cop calls config.for_cop(another_cop)).

Strangely enough, Lint/AmbiguousOperator needs everyone else's configs. I excluded it from the diagram in order to keep it clean.

Other than that, the dependency graph has 28 edges.

cop.diff

diff --git a/lib/rubocop/cop/cop.rb b/lib/rubocop/cop/cop.rb
index 1859218..d781f98 100644
--- a/lib/rubocop/cop/cop.rb
+++ b/lib/rubocop/cop/cop.rb
@@ -114,8 +114,23 @@ module RuboCop
           given_names.include?(cop_type.to_s.capitalize)
       end
 
+require 'set'
+KNOWN_CONFIGS = File.readlines('ress.csv').map {|x| x.chomp.split(',')}.to_set
+DEPS = Set.new
+
       def initialize(config = nil, options = nil)
-        @config = config || Config.new
+        @config = c = config || Config.new
+        name = self.class.cop_name
+        if KNOWN_CONFIGS.add?(c)
+          c.define_singleton_method(:for_cop) do |cop|
+            d = [name, cop.respond_to?(:cop_name) ? cop.cop_name : cop]
+            if DEPS.add?(d)
+              File.open('ress.csv', 'a+') { |f| f.puts(d.join(',')) }
+            end
+            super(cop)
+          end
+        end
+
         @options = options || { debug: false }
 
         @offenses = []

make_graph.sh

dot -Tpng rubo.dot -o rubocop.png

rubo.dot

digraph Rubocop {
  rankdir=RL
  "Metrics/LineLength" -> "Style/IfUnlessModifier"
  "Style/SpaceInsideBlockBraces" -> "Style/SpaceAfterSemicolon"
  "Style/BlockDelimiters" -> "Style/SpaceInsideBlockBraces"
  "IndentationWidth" -> "Style/MultilineOperationIndentation"
  "Style/IndentationWidth" -> "Style/MultilineOperationIndentation"
  "Lint/EndAlignment" -> "Style/ElseAlignment"
  "Style/MissingElse" -> "Style/EmptyElse"
  "Style/CollectionMethods" -> "Performance/Detect"
  "Style/BlockDelimiters" -> "Style/SpaceBeforeBlockBraces"
  "IndentationWidth" -> "Style/MultilineMethodCallIndentation"
  "Style/IndentationWidth" -> "Style/MultilineMethodCallIndentation"
  "Style/PercentLiteralDelimiters" -> "Style/RegexpLiteral"
  "Style/UnlessElse" -> "Style/MissingElse"
  "Style/EmptyElse" -> "Style/MissingElse"
  "IndentationWidth" -> "Style/AccessModifierIndentation"
  "IndentationWidth" -> "Style/CaseIndentation"
  "Style/PercentLiteralDelimiters" -> "Style/CommandLiteral"
  "IndentationWidth" -> "Style/IndentArray"
  "IndentationWidth" -> "Style/FirstParameterIndentation"
  "IndentationWidth" -> "Style/IndentAssignment"
  "Style/AlignHash" -> "Style/SpaceAroundOperators"
  "IndentationWidth" -> "Style/AlignParameters"
  "Style/IndentationConsistency" -> "Style/IndentationWidth"
  "Style/CommentAnnotation" -> "Style/Documentation"
  "Style/AlignHash" -> "Style/IndentHash"
  "IndentationWidth" -> "Style/IndentHash"
  "IndentationWidth" -> "Style/SingleLineMethods"
  "Style/StringLiterals" -> "Style/EmptyLiteral"
}

rubocop.png

script.rb

# copied from irb
data = File.readlines('ress.csv').map {|x| x.chomp.split(',')}.reject{|x,y| x == y || x == 'Lint/AmbiguousOperator' }
File.open('rubo.dot', 'w') { |f| f.puts('digraph Rubocop {'); f.puts("  rankdir=LR");  f.puts(data.map {|x,y| "  \"#{x}\" -> \"#{y}\"" }); f.puts('}') }