cleaning up code and adding test coverage for attribute and expression.

2 files changed, 20 insertions, 12 deletions

diff --git a/lib/active_relation/primitives/attribute.rb b/lib/active_relation/primitives/attribute.rb
index c17118f1e8..e6df5cd87c 100644
--- a/lib/active_relation/primitives/attribute.rb
+++ b/lib/active_relation/primitives/attribute.rb
@@ -30,17 +30,18 @@ module ActiveRelation
     end
 
     def ==(other)
-      self.class == other.class and relation == other.relation and name == other.name and @alias == other.alias and ancestor == other.ancestor
+      self.class == other.class and
+        relation == other.relation and
+        name     == other.name and
+        @alias   == other.alias and
+        ancestor == other.ancestor
     end
+    alias_method :eql?, :==
     
     def =~(other)
-      !(history & other.history).empty?
+      !(history & other.send(:history)).empty?
     end
     
-    def history
-      [self] + (ancestor ? [ancestor, ancestor.history].flatten : [])
-    end
-
     module Predications
       def equals(other)
         Equality.new(self, other)
@@ -96,8 +97,14 @@ module ActiveRelation
     end
     
     private
+    delegate :hash, :to => :relation
+    
     def prefix
       relation.prefix_for(self)
     end
+    
+    def history
+      [self] + (ancestor ? [ancestor, ancestor.send(:history)].flatten : [])
+    end
   end
 end
\ No newline at end of file
diff --git a/lib/active_relation/primitives/expression.rb b/lib/active_relation/primitives/expression.rb
index 47658c49da..a64219e9d1 100644
--- a/lib/active_relation/primitives/expression.rb
+++ b/lib/active_relation/primitives/expression.rb
@@ -11,7 +11,7 @@ module ActiveRelation
 
     module Transformations
       def substitute(new_relation)
-        Expression.new(attribute.substitute(new_relation), function_sql, @alias, self)
+        new_relation == relation ? self : Expression.new(attribute.substitute(new_relation), function_sql, @alias, self)
       end
     
       def as(aliaz)
@@ -34,17 +34,18 @@ module ActiveRelation
       self.class == other.class and attribute == other.attribute and function_sql == other.function_sql and ancestor == other.ancestor and @alias == other.alias
     end
     alias_method :eql?, :==
+    
+    def =~(other)
+      !(history & other.send(:history)).empty?
+    end
 
+    private
     def hash
       attribute.hash + function_sql.hash
     end
     
-    def =~(other)
-      !(history & other.history).empty?
-    end
-
     def history
-      [self] + (ancestor ? [ancestor, ancestor.history].flatten : [])
+      [self] + (ancestor ? [ancestor, ancestor.send(:history)].flatten : [])
     end
   end
 end
\ No newline at end of file