Add mutation A.const_get(:B) -> A::B

Closes #422

Changelog.md

@@ -1,3 +1,7 @@
+# v0.8.4 2015-09-xx
+
+* Add mutation `A.const_get(:B)` -> `A::B` #426
+
 # v0.8.3 2015-09-01
 
 * Remove invalid mutation `super(...)` to `super`

config/flay.yml

@@ -1,3 +1,3 @@
 ---
 threshold: 18
-total_score: 1200
+total_score: 1214

lib/mutant.rb

@@ -49,6 +49,7 @@ require 'mutant/ast/named_children'
 require 'mutant/ast/node_predicates'
 require 'mutant/ast/meta'
 require 'mutant/ast/meta/send'
+require 'mutant/ast/meta/symbol'
 require 'mutant/ast/meta/optarg'
 require 'mutant/ast/meta/resbody'
 require 'mutant/actor'

lib/mutant/ast/meta/symbol.rb

@@ -0,0 +1,15 @@
+module Mutant
+  module AST
+    # Node meta information mixin
+    module Meta
+
+      # Metadata for symbol nodes
+      class Symbol
+        include NamedChildren, Concord.new(:node)
+
+        children :name
+
+      end # Symbol
+    end # Meta
+  end # AST
+end # Mutant

lib/mutant/mutator/node/send.rb

@@ -90,11 +90,23 @@ module Mutant
         def normal_dispatch
           emit_naked_receiver
           emit_selector_replacement
+          emit_const_get_mutation
           emit_argument_propagation
           mutate_receiver
           mutate_arguments
         end
 
+        # Emit mutation from `const_get` to const literal
+        #
+        # @return [undefined]
+        #
+        # @api private
+        def emit_const_get_mutation
+          return unless selector.equal?(:const_get) && n_sym?(arguments.first)
+
+          emit(s(:const, receiver, AST::Meta::Symbol.new(arguments.first).name))
+        end
+
         # Emit selector replacement
         #
         # @return [undefined]

meta/send.rb

@@ -14,6 +14,32 @@ Mutant::Meta::Example.add do
   mutation 'b'
 end
 
+Mutant::Meta::Example.add do
+  source 'A.const_get(:B)'
+
+  singleton_mutations
+  mutation 'A::B'
+  mutation 'A.const_get'
+  mutation 'A'
+  mutation ':B'
+  mutation 'A.const_get(nil)'
+  mutation 'A.const_get(self)'
+  mutation 'A.const_get(:B__mutant__)'
+  mutation 'self.const_get(:B)'
+end
+
+Mutant::Meta::Example.add do
+  source 'A.const_get(bar)'
+
+  singleton_mutations
+  mutation 'A.const_get'
+  mutation 'A'
+  mutation 'bar'
+  mutation 'A.const_get(nil)'
+  mutation 'A.const_get(self)'
+  mutation 'self.const_get(bar)'
+end
+
 Mutant::Meta::Example.add do
   source 'a >= b'