reducing function calls and using faster methods for testing

Author: tenderlove

activerecord/lib/active_record/relation.rb

@@ -99,7 +99,7 @@ def many?
       if block_given?
         to_a.many? { |*block_args| yield(*block_args) }
       else
-        @limit_value.present? ? to_a.many? : size > 1
+        @limit_value ? to_a.many? : size > 1
       end
     end
 
@@ -316,12 +316,12 @@ def to_sql
 
     def scope_for_create
       @scope_for_create ||= begin
-        @create_with_value || @where_values.inject({}) do |hash, where|
-          if where.is_a?(Arel::Predicates::Equality)
-            hash[where.operand1.name] = where.operand2.respond_to?(:value) ? where.operand2.value : where.operand2
-          end
-          hash
-        end
+        @create_with_value || Hash[
+          @where_values.grep(Arel::Predicates::Equality).map { |where|
+            [where.operand1.name,
+             where.operand2.respond_to?(:value) ?
+             where.operand2.value : where.operand2]
+        }]
       end
     end
 

activerecord/lib/active_record/relation/query_methods.rb

@@ -129,7 +129,7 @@ def custom_join_sql(*joins)
     def build_arel
       arel = table
 
-      arel = build_joins(arel, @joins_values) if @joins_values.present?
+      arel = build_joins(arel, @joins_values) unless @joins_values.empty?
 
       @where_values.uniq.each do |where|
         next if where.blank?
@@ -145,7 +145,7 @@ def build_arel
 
       arel = arel.having(*@having_values.uniq.select{|h| h.present?}) if @having_values.present?
 
-      arel = arel.take(@limit_value) if @limit_value.present?
+      arel = arel.take(@limit_value) if @limit_value
       arel = arel.skip(@offset_value) if @offset_value.present?
 
       arel = arel.group(*@group_values.uniq.select{|g| g.present?}) if @group_values.present?
@@ -155,13 +155,7 @@ def build_arel
       arel = build_select(arel, @select_values.uniq)
 
       arel = arel.from(@from_value) if @from_value.present?
-
-      case @lock_value
-      when TrueClass
-        arel = arel.lock
-      when String
-        arel = arel.lock(@lock_value)
-      end if @lock_value.present?
+      arel = arel.lock(@lock_value) if @lock_value
 
       arel
     end