Skip method subjects defined in blocks

* No easy way to insert mutants on these via current monkey patching
  loader
* The blocks are typically part of a method building library when those
  libraries are mutated the def/defs nodes will be part of an mutated
  block that is included in a subject.

[fix #254]

config/flay.yml

@@ -1,3 +1,3 @@
 ---
 threshold: 18
-total_score: 1094
+total_score: 1098

lib/mutant/matcher/method.rb

@@ -3,7 +3,7 @@ module Mutant
     # Matcher for subjects that are a specific method
     class Method < self
       include Adamantium::Flat, Concord::Public.new(:env, :scope, :target_method)
-      include Equalizer.new(:identification)
+      include AST::NodePredicates, Equalizer.new(:identification)
 
       # Methods within rbx kernel directory are precompiled and their source
       # cannot be accessed via reading source location. Same for methods created by eval.
@@ -40,7 +40,10 @@ module Mutant
       def skip?
         location = source_location
         if location.nil? || BLACKLIST.match(location.first)
-          env.warn(format('%s does not have valid source location unable to emit matcher', target_method.inspect))
+          env.warn(format('%s does not have valid source location unable to emit subject', target_method.inspect))
+          true
+        elsif matched_node_path.any?(&method(:n_block?))
+          env.warn(format('%s is defined from a 3rd party lib unable to emit subject', target_method.inspect))
           true
         else
           false

spec/shared/method_matcher_behavior.rb

@@ -17,7 +17,7 @@ RSpec.shared_examples_for 'a method matcher' do
   end
 
   it 'should have correct line number' do
-    expect(node.location.expression.line - base).to eql(method_line)
+    expect(node.location.expression.line).to eql(method_line)
   end
 
   it 'should have correct arity' do

spec/unit/mutant/matcher/method/instance_spec.rb

@@ -11,10 +11,10 @@ RSpec.describe Mutant::Matcher::Method::Instance do
     let(:method)       { scope.instance_method(method_name)        }
     let(:yields)       { []                                        }
     let(:namespace)    { self.class                                }
-    let(:scope)        { self.class::Foo                           }
     let(:type)         { :def                                      }
-    let(:method_name)  { :bar                                      }
+    let(:method_name)  { :foo                                      }
     let(:method_arity) { 0                                         }
+    let(:base)         { TestApp::InstanceMethodTests              }
 
     def name
       node.children[0]
@@ -36,109 +36,79 @@ RSpec.describe Mutant::Matcher::Method::Instance do
       it 'does warn' do
         subject
         expect(reporter.warn_calls.last).to(
-          eql("#{method.inspect} does not have valid source location unable to emit matcher")
+          eql("#{method.inspect} does not have valid source location unable to emit subject")
         )
       end
     end
 
     context 'when method is defined once' do
-      let(:base) { __LINE__ }
+      let(:scope)       { base::DefinedOnce }
-      class self::Foo
+      let(:method_line) { 7                 }
-        def bar; end
-      end
-
-      let(:method_line) { 2 }
 
       it_should_behave_like 'a method matcher'
     end
 
     context 'when method is defined once with a memoizer' do
-      let(:base) { __LINE__ }
+      let(:scope)       { base::WithMemoizer }
-      class self::Foo
+      let(:method_line) { 12                 }
-        def bar; end
-        include Adamantium
-        memoize :bar
-      end
-
-      let(:method_line) { 2 }
 
       it_should_behave_like 'a method matcher'
     end
 
     context 'when method is defined multiple times' do
       context 'on different lines' do
-        let(:base) { __LINE__ }
+        let(:scope)        { base::DefinedMultipleTimes::DifferentLines }
-        class self::Foo
+        let(:method_line)  { 21                                         }
-          def bar
-          end
-
-          def bar(_arg)
-          end
-        end
-
-        let(:method_line)  { 5 }
         let(:method_arity) { 1                                          }
 
         it_should_behave_like 'a method matcher'
       end
 
       context 'on the same line' do
-        let(:base) { __LINE__ }
+        let(:scope)        { base::DefinedMultipleTimes::SameLineSameScope }
-        class self::Foo
+        let(:method_line)  { 26                                            }
-          def bar; end; def bar(_arg); end
-        end
-
-        let(:method_line)  { 2 }
         let(:method_arity) { 1                                             }
 
         it_should_behave_like 'a method matcher'
       end
 
       context 'on the same line with different scope' do
-        let(:base) { __LINE__ }
+        let(:scope)        { base::DefinedMultipleTimes::SameLineDifferentScope }
-        class self::Foo
+        let(:method_line)  { 30                                                 }
-          def self.bar; end; def bar(_arg); end
-        end
-
-        let(:method_line)  { 2 }
         let(:method_arity) { 1                                                  }
 
         it_should_behave_like 'a method matcher'
       end
 
-      context 'when nested' do
+      context 'in module eval' do
-        let(:pattern) { 'Foo::Bar#baz' }
+        let(:scope) { base::InModuleEval }
 
-        context 'in class' do
+        it 'does not emit matcher' do
-          let(:base) { __LINE__ }
+          subject
-          class self::Foo
+          expect(yields.length).to be(0)
-            class Bar
-              def baz
         end
+
+        it 'does warn' do
+          subject
+          expect(reporter.warn_calls.last).to(
+            eql("#{method.inspect} is defined from a 3rd party lib unable to emit subject")
+          )
         end
       end
 
-          let(:method_line) { 3                    }
+      context 'in class eval' do
-          let(:method_name) { :baz                 }
+        let(:scope) { base::InClassEval }
-          let(:scope)       { self.class::Foo::Bar }
 
-          it_should_behave_like 'a method matcher'
+        it 'does not emit matcher' do
+          subject
+          expect(yields.length).to be(0)
         end
 
-        context 'in module' do
+        it 'does warn' do
-          let(:base) { __LINE__ }
+          subject
-          module self::Foo
+          expect(reporter.warn_calls.last).to(
-            class Bar
+            eql("#{method.inspect} is defined from a 3rd party lib unable to emit subject")
-              def baz
+          )
-              end
-            end
-          end
-
-          let(:method_line) { 3                    }
-          let(:method_name) { :baz                 }
-          let(:scope)       { self.class::Foo::Bar }
-
-          it_should_behave_like 'a method matcher'
         end
       end
     end

spec/unit/mutant/matcher/method/singleton_spec.rb

@@ -6,10 +6,10 @@ RSpec.describe Mutant::Matcher::Method::Singleton, '#each' do
   let(:method)       { scope.method(method_name)               }
   let(:env)          { Fixtures::TEST_ENV                      }
   let(:yields)       { []                                      }
-  let(:namespace)    { self.class                              }
-  let(:scope)        { self.class::Foo                         }
   let(:type)         { :defs                                   }
+  let(:method_name)  { :foo                                    }
   let(:method_arity) { 0                                       }
+  let(:base)         { TestApp::SingletonMethodTests           }
 
   def name
     node.children[1]
@@ -22,14 +22,8 @@ RSpec.describe Mutant::Matcher::Method::Singleton, '#each' do
   context 'on singleton methods' do
 
     context 'when also defined on lvar' do
-      let(:base) { __LINE__ }
+      let(:scope)       { base::AlsoDefinedOnLvar }
-      class self::Foo
+      let(:method_line) { 63                      }
-        a = Object.new
-        def a.bar; end; def self.bar; end
-      end
-
-      let(:method_name) { :bar }
-      let(:method_line) { 3    }
 
       it_should_behave_like 'a method matcher'
 
@@ -42,13 +36,8 @@ RSpec.describe Mutant::Matcher::Method::Singleton, '#each' do
     end
 
     context 'when defined on self' do
-      let(:base) { __LINE__ }
+      let(:scope)       { base::DefinedOnSelf }
-      class self::Foo
+      let(:method_line) { 58                  }
-        def self.bar; end
-      end
-
-      let(:method_name) { :bar }
-      let(:method_line) { 2    }
 
       it_should_behave_like 'a method matcher'
     end
@@ -56,34 +45,15 @@ RSpec.describe Mutant::Matcher::Method::Singleton, '#each' do
     context 'when defined on constant' do
 
       context 'inside namespace' do
-        let(:base) { __LINE__ }
+        let(:scope)       { base::DefinedOnConstant::InsideNamespace }
-        module self::Namespace
+        let(:method_line) { 68                                       }
-          class Foo
-            def Foo.bar
-            end
-          end
-        end
-
-        let(:scope)       { self.class::Namespace::Foo }
-        let(:method_name) { :bar                       }
-        let(:method_line) { 3                          }
 
         it_should_behave_like 'a method matcher'
       end
 
       context 'outside namespace' do
-        let(:base) { __LINE__ }
+        let(:method_line) { 75                                        }
-        module self::Namespace
+        let(:scope)       { base::DefinedOnConstant::OutsideNamespace }
-          class Foo
-          end
-
-          def Foo.bar
-          end
-        end
-
-        let(:method_name) { :bar                       }
-        let(:method_line) { 5                          }
-        let(:scope)       { self.class::Namespace::Foo }
 
         it_should_behave_like 'a method matcher'
       end
@@ -91,21 +61,9 @@ RSpec.describe Mutant::Matcher::Method::Singleton, '#each' do
 
     context 'when defined multiple times in the same line' do
       context 'with method on different scope' do
-        let(:base) { __LINE__ }
+        let(:scope)        { base::DefinedMultipleTimes::SameLine::DifferentScope }
-        module self::Namespace
+        let(:method_line)  { 94                                                   }
-          module Foo; end
+        let(:method_arity) { 1                                                    }
-          module Bar
-            def self.baz
-            end
-            def Foo.baz(_arg)
-            end
-          end
-        end
-
-        let(:scope)        { self.class::Namespace::Bar }
-        let(:method_name)  { :baz                       }
-        let(:method_line)  { 4                          }
-        let(:method_arity) { 0                          }
 
         it_should_behave_like 'a method matcher'
       end

test_app/lib/test_app.rb

@@ -2,6 +2,100 @@
 
 # Namespace for test application
 module TestApp
+  module InstanceMethodTests
+    module DefinedOnce
+      def foo; end
+    end
+
+    class WithMemoizer
+      include Adamantium
+      def foo; end
+      memoize :foo
+    end
+
+    module DefinedMultipleTimes
+      class DifferentLines
+        def foo
+        end
+
+        def foo(_arg)
+        end
+      end
+
+      class SameLineSameScope
+        def foo; end; def foo(_arg); end
+      end
+
+      class SameLineDifferentScope
+        def self.foo; end; def foo(_arg); end
+      end
+    end
+
+    class InClassEval
+      class_eval do
+        def foo
+        end
+      end
+    end
+
+    class InModuleEval
+      module_eval do
+        def foo
+        end
+      end
+    end
+
+    class InInstanceEval
+      module_eval do
+        def foo
+        end
+      end
+    end
+  end
+
+  module SingletonMethodTests
+    module DefinedOnSelf
+      def self.foo; end
+    end
+
+    module AlsoDefinedOnLvar
+      a = Object.new
+      def a.foo; end; def self.foo; end
+    end
+
+    module DefinedOnConstant
+      module InsideNamespace
+        def InsideNamespace.foo
+        end
+      end
+
+      module OutsideNamespace
+      end
+
+      def OutsideNamespace.foo
+      end
+    end
+
+    module DefinedMultipleTimes
+      module DifferentLines
+        def self.foo
+        end
+
+        def self.foo(_arg)
+        end
+      end
+
+      module SameLine
+        module SameScope
+          def self.foo; end; def self.foo(_arg); end;
+        end
+
+        module DifferentScope
+          def self.foo; end; def DifferentScope.foo(_arg); end
+        end
+      end
+    end
+  end
 end
 
 require 'test_app/literal'