Merge pull request #511 from mbj/feature/key-predicate-mutations

Add mutations from `Hash#[]` and `Hash#fetch` to `Hash#key?`

Changelog.md

@@ -1,3 +1,9 @@
+# Master (unreleased)
+
+* Add mutation from `Hash#[]` to `Hash#key?` (#511)
+* Add mutation from `Hash#fetch` to `Hash#key?` (#511)
+* Add mutation from `#at` to `#key?` (#511)
+
 # v0.8.8 2015-xx-xx
 
 * Drop support for rspec-3.2

lib/mutant/mutator/node/send.rb

@@ -26,8 +26,9 @@ module Mutant
           to_i:          %i[to_int],
           to_a:          %i[to_ary],
           to_h:          %i[to_hash],
-          at:            %i[fetch],
-          :[] =>         %i[at fetch],
+          at:            %i[fetch key?],
+          fetch:         %i[key?],
+          :[] =>         %i[at fetch key?],
           :== =>         %i[eql? equal?],
           :>= =>         %i[> == eql? equal?],
           :<= =>         %i[< == eql? equal?],

meta/send.rb

@@ -359,6 +359,15 @@ Mutant::Meta::Example.add do
   mutation 'foo(nil)'
 end
 
+Mutant::Meta::Example.add do
+  source 'self.fetch(nil)'
+
+  singleton_mutations
+  mutation 'self.fetch'
+  mutation 'fetch(nil)'
+  mutation 'self.key?(nil)'
+end
+
 Unparser::Constants::KEYWORDS.each do |keyword|
   Mutant::Meta::Example.add do
     source "foo.#{keyword}(nil)"
@@ -405,6 +414,7 @@ Mutant::Meta::Example.add do
   mutation 'foo[]'
   mutation 'foo.at(1)'
   mutation 'foo.fetch(1)'
+  mutation 'foo.key?(1)'
   mutation 'self[1]'
   mutation 'foo[0]'
   mutation 'foo[2]'
@@ -420,6 +430,7 @@ Mutant::Meta::Example.add do
   mutation 'self.foo'
   mutation 'self.foo.at()'
   mutation 'self.foo.fetch()'
+  mutation 'self.foo.key?()'
   mutation 'self[]'
   mutation 'foo[]'
 end
@@ -433,6 +444,7 @@ Mutant::Meta::Example.add do
   mutation 'self[]'
   mutation 'self.at(foo)'
   mutation 'self.fetch(foo)'
+  mutation 'self.key?(foo)'
   mutation 'foo'
 end
 
@@ -444,6 +456,7 @@ Mutant::Meta::Example.add do
   mutation 'foo[]'
   mutation 'foo.at(*bar)'
   mutation 'foo.fetch(*bar)'
+  mutation 'foo.key?(*bar)'
   mutation 'foo[nil]'
   mutation 'foo[self]'
   mutation 'foo[bar]'