Change to explicit method call in completion (#369)

Ensure that methods are called even when local variables are defined.
see: #368

lib/irb/completion.rb

@@ -11,7 +11,29 @@
 
 module IRB
   module InputCompletor # :nodoc:
+    using Module.new {
+      refine ::Binding do
+        def eval_methods
+          ::Kernel.instance_method(:methods).bind(eval("self")).call
+        end
+
+        def eval_private_methods
+          ::Kernel.instance_method(:private_methods).bind(eval("self")).call
+        end
+
+        def eval_instance_variables
+          ::Kernel.instance_method(:instance_variables).bind(eval("self")).call
+        end
 
+        def eval_global_variables
+          ::Kernel.instance_method(:global_variables).bind(eval("self")).call
+        end
+
+        def eval_class_constants
+          ::Module.instance_method(:constants).bind(eval("self.class")).call
+        end
+      end
+    }
 
     # Set of reserved words used by Ruby, you should not use these for
     # constants or variables
@@ -303,10 +325,10 @@ def self.retrieve_completion_data(input, bind: IRB.conf[:MAIN_CONTEXT].workspace
         sep = $2
         message = $3
 
-        gv = eval("global_variables", bind).collect{|m| m.to_s}.push("true", "false", "nil")
-        lv = eval("local_variables", bind).collect{|m| m.to_s}
-        iv = eval("instance_variables", bind).collect{|m| m.to_s}
-        cv = eval("self.class.constants", bind).collect{|m| m.to_s}
+        gv = bind.eval_global_variables.collect{|m| m.to_s}.push("true", "false", "nil")
+        lv = bind.local_variables.collect{|m| m.to_s}
+        iv = bind.eval_instance_variables.collect{|m| m.to_s}
+        cv = bind.eval_class_constants.collect{|m| m.to_s}
 
         if (gv | lv | iv | cv).include?(receiver) or /^[A-Z]/ =~ receiver && /\./ !~ receiver
           # foo.func and foo is var. OR
@@ -356,17 +378,17 @@ def self.retrieve_completion_data(input, bind: IRB.conf[:MAIN_CONTEXT].workspace
 
       else
         if doc_namespace
-          vars = eval("local_variables | instance_variables", bind).collect{|m| m.to_s}
+          vars = (bind.local_variables | bind.eval_instance_variables).collect{|m| m.to_s}
           perfect_match_var = vars.find{|m| m.to_s == input}
           if perfect_match_var
             eval("#{perfect_match_var}.class.name", bind)
           else
-            candidates = eval("methods | private_methods | local_variables | instance_variables | self.class.constants", bind).collect{|m| m.to_s}
+            candidates = (bind.eval_methods | bind.eval_private_methods | bind.local_variables | bind.eval_instance_variables | bind.eval_class_constants).collect{|m| m.to_s}
             candidates |= ReservedWords
             candidates.find{ |i| i == input }
           end
         else
-          candidates = eval("methods | private_methods | local_variables | instance_variables | self.class.constants", bind).collect{|m| m.to_s}
+          candidates = (bind.eval_methods | bind.eval_private_methods | bind.local_variables | bind.eval_instance_variables | bind.eval_class_constants).collect{|m| m.to_s}
           candidates |= ReservedWords
           candidates.grep(/^#{Regexp.quote(input)}/)
         end

test/irb/test_completion.rb

@@ -152,11 +152,56 @@ def test_complete_require_relative
     end
 
     def test_complete_variable
+      # Bug fix issues https://github.com/ruby/irb/issues/368
+      # Variables other than `str_example` and `@str_example` are defined to ensure that irb completion does not cause unintended behavior
       str_example = ''
-      str_example.clear # suppress "assigned but unused variable" warning
+      @str_example = ''
+      private_methods = ''
+      methods = ''
+      global_variables = ''
+      local_variables = ''
+      instance_variables = ''
+
+      # suppress "assigned but unused variable" warning
+      str_example.clear
+      @str_example.clear
+      private_methods.clear
+      methods.clear
+      global_variables.clear
+      local_variables.clear
+      instance_variables.clear
+
       assert_include(IRB::InputCompletor.retrieve_completion_data("str_examp", bind: binding), "str_example")
       assert_equal(IRB::InputCompletor.retrieve_completion_data("str_example", bind: binding, doc_namespace: true), "String")
       assert_equal(IRB::InputCompletor.retrieve_completion_data("str_example.to_s", bind: binding, doc_namespace: true), "String.to_s")
+
+      assert_include(IRB::InputCompletor.retrieve_completion_data("@str_examp", bind: binding), "@str_example")
+      assert_equal(IRB::InputCompletor.retrieve_completion_data("@str_example", bind: binding, doc_namespace: true), "String")
+      assert_equal(IRB::InputCompletor.retrieve_completion_data("@str_example.to_s", bind: binding, doc_namespace: true), "String.to_s")
+    end
+
+    def test_complete_methods
+      obj = Object.new
+      obj.singleton_class.class_eval {
+        def public_hoge; end
+        private def private_hoge; end
+
+        # Support for overriding #methods etc.
+        def methods; end
+        def private_methods; end
+        def global_variables; end
+        def local_variables; end
+        def instance_variables; end
+      }
+      bind = obj.instance_exec { binding }
+
+      assert_include(IRB::InputCompletor.retrieve_completion_data("public_hog", bind: bind), "public_hoge")
+      assert_include(IRB::InputCompletor.retrieve_completion_data("public_hoge.to_s", bind: bind), "public_hoge.to_s")
+      assert_include(IRB::InputCompletor.retrieve_completion_data("public_hoge", bind: bind, doc_namespace: true), "public_hoge")
+
+      assert_include(IRB::InputCompletor.retrieve_completion_data("private_hog", bind: bind), "private_hoge")
+      assert_include(IRB::InputCompletor.retrieve_completion_data("private_hoge.to_s", bind: bind), "private_hoge.to_s")
+      assert_include(IRB::InputCompletor.retrieve_completion_data("private_hoge", bind: bind, doc_namespace: true), "private_hoge")
     end
 
     def test_complete_class_method