Add a cop to catch _eval usage, update all block calls to use _exec instead

Author: rmosolgo

.rubocop.yml

@@ -1,5 +1,6 @@
 require:
   - ./cop/development/none_without_block_cop
+  - ./cop/development/no_eval_cop
   - ./cop/development/no_focus_cop
   - ./lib/graphql/rubocop/graphql/default_null_true
   - ./lib/graphql/rubocop/graphql/default_required_true
@@ -51,6 +52,10 @@ Development/NoneWithoutBlockCop:
     - "lib/**/*"
     - "spec/**/*"
 
+Development/NoEvalCop:
+  Include:
+    - "lib/**/*"
+
 Development/NoFocusCop:
   Include:
     - "spec/**/*"

cop/development/no_eval_cop.rb

@@ -0,0 +1,18 @@
+# frozen_string_literal: true
+require 'rubocop'
+
+module Cop
+  module Development
+    class NoEvalCop < RuboCop::Cop::Base
+      MSG_TEMPLATE = "Don't use `%{eval_method_name}` which accept strings and may result in unexpected code being generated. Use `%{exec_method_name}` instead, and pass a block."
+
+      def on_send(node)
+        case node.method_name
+        when :module_eval, :class_eval, :instance_eval
+          message = MSG_TEMPLATE % { eval_method_name: node.method_name, exec_method_name: node.method_name.to_s.sub("eval", "exec").to_sym }
+          add_offense node, message: message
+        end
+      end
+    end
+  end
+end

lib/graphql/schema/argument.rb

@@ -89,11 +89,8 @@ def initialize(arg_name = nil, type_expr = nil, desc = nil, required: true, type
         end
 
         if definition_block
-          if definition_block.arity == 1
-            instance_exec(self, &definition_block)
-          else
-            instance_eval(&definition_block)
-          end
+          # `self` will still be self, it will also be the first argument to the block:
+          instance_exec(self, &definition_block)
         end
       end
 

lib/graphql/schema/directive.rb

@@ -99,7 +99,7 @@ def repeatable(new_value)
 
         def inherited(subclass)
           super
-          subclass.class_eval do
+          subclass.class_exec do
             @default_graphql_name ||= nil
           end
         end

lib/graphql/schema/enum_value.rb

@@ -47,7 +47,7 @@ def initialize(graphql_name, desc = nil, owner:, ast_node: nil, directives: nil,
         end
 
         if block_given?
-          instance_eval(&block)
+          instance_exec(self, &block)
         end
       end
 

lib/graphql/schema/interface.rb

@@ -29,7 +29,7 @@ def definition_methods(&block)
             const_set(:DefinitionMethods, defn_methods_module)
             extend(self::DefinitionMethods)
           end
-          self::DefinitionMethods.module_eval(&block)
+          self::DefinitionMethods.module_exec(&block)
         end
 
         # @see {Schema::Warden} hides interfaces without visible implementations

lib/graphql/schema/member/has_directives.rb

@@ -6,7 +6,7 @@ class Member
       module HasDirectives
         def self.extended(child_cls)
           super
-          child_cls.module_eval { self.own_directives = nil }
+          child_cls.module_exec { self.own_directives = nil }
         end
 
         def inherited(child_cls)

lib/graphql/schema/member/has_fields.rb

@@ -183,7 +183,7 @@ def self.extended(child_class)
 
         def inherited(subclass)
           super
-          subclass.class_eval do
+          subclass.class_exec do
             @own_fields ||= nil
             @field_class ||= nil
           end

lib/graphql/schema/member/has_interfaces.rb

@@ -133,7 +133,7 @@ def self.extended(child_class)
 
         def inherited(subclass)
           super
-          subclass.class_eval do
+          subclass.class_exec do
             @own_interface_type_memberships ||= nil
           end
         end

lib/graphql/schema/member/scoped.rb

@@ -30,7 +30,7 @@ def reauthorize_scoped_objects(new_value = nil)
 
         def inherited(subclass)
           super
-          subclass.class_eval do
+          subclass.class_exec do
             @reauthorize_scoped_objects = nil
           end
         end

lib/graphql/schema/member/type_system_helpers.rb

@@ -43,7 +43,7 @@ def kind
         private
 
         def inherited(subclass)
-          subclass.class_eval do
+          subclass.class_exec do
             @to_non_null_type ||= nil
             @to_list_type ||= nil
           end

lib/graphql/types/relay/connection_behaviors.rb

@@ -13,7 +13,7 @@ def self.included(child_class)
           child_class.node_nullable(true)
           child_class.edges_nullable(true)
           child_class.edge_nullable(true)
-          child_class.module_eval {
+          child_class.module_exec {
             self.edge_type = nil
             self.node_type = nil
             self.edge_class = nil

lib/graphql/types/relay/edge_behaviors.rb

@@ -8,7 +8,7 @@ def self.included(child_class)
           child_class.description("An edge in a connection.")
           child_class.field(:cursor, String, null: false, description: "A cursor for use in pagination.")
           child_class.extend(ClassMethods)
-          child_class.class_eval { self.node_type = nil }
+          child_class.class_exec { self.node_type = nil }
           child_class.node_nullable(true)
         end