Merge pull request #135 from RichardBradley/master

fix index required false-positive

lib/rails_best_practices/reviews/always_add_db_index_review.rb

@@ -42,6 +42,8 @@ def initialize
       add_callback :start_command_call do |node|
         if %w(integer string).include? node.message.to_s
           remember_foreign_key_columns(node)
+        elsif "index" == node.message.to_s
+          remember_index_columns_inside_table(node)
         end
       end
 
@@ -57,7 +59,7 @@ def initialize
         when "create_table"
           remember_table_nodes(node)
         when "add_index"
-          remember_index_columns(node)
+          remember_index_columns_outside_table(node)
         end
       end
 
@@ -81,15 +83,28 @@ def initialize
       end
 
       private
-        # remember the node as index columns
-        def remember_index_columns(node)
+        # remember the node as index columns, when used outside a table
+        # block, i.e.
+        #   add_index :table_name, :column_name
+        def remember_index_columns_outside_table(node)
           table_name = node.arguments.all.first.to_s
           index_column = node.arguments.all[1].to_object
 
           @index_columns[table_name] ||= []
           @index_columns[table_name] << index_column
         end
 
+        # remember the node as index columns, when used inside a table
+        # block, i.e.
+        #    t.index [:column_name, ...]
+        def remember_index_columns_inside_table(node)
+          table_name = @table_name
+          index_column = node.arguments.all.first.to_object
+
+          @index_columns[table_name] ||= []
+          @index_columns[table_name] << index_column
+        end
+
         # remember table nodes
         def remember_table_nodes(node)
           @table_name = node.arguments.all.first.to_s

spec/rails_best_practices/reviews/always_add_db_index_review_spec.rb

@@ -153,6 +153,24 @@ module Reviews
         runner.should have(0).errors
       end
 
+      it "should not always add db index with t.index" do
+        # e.g. schema_plus creates indices like this https://github.com/lomba/schema_plus
+        content = <<-EOF
+        ActiveRecord::Schema.define(version: 20100603080629) do
+          create_table "comments", force: true do |t|
+            t.string "content"
+            t.integer "post_id"
+            t.index ["post_id"], :name => "index_comments_on_post_id"
+          end
+          create_table "posts", force: true do |t|
+          end
+        end
+        EOF
+        runner.review('db/schema.rb', content)
+        runner.after_review
+        runner.should have(0).errors
+      end
+
       it "should not always add db index with only _type column" do
         content = <<-EOF
         ActiveRecord::Schema.define(version: 20100603080629) do