Don't overwrite signatures of existing methods in AR classes

lib/bogus/active_record_accessors.rb

@@ -11,7 +11,7 @@ class ActiveRecordAccessors
 
     def all
       return [] unless klass < ActiveRecord::Base
-      klass.columns.map(&:name)
+      return missing_attributes
     end
 
     def get(name)
@@ -24,6 +24,14 @@ def instance_methods
       @instance_methods.call(klass)
     end
 
+    def all_attributes
+      klass.columns.map(&:name).map(&:to_sym)
+    end
+
+    def missing_attributes
+      all_attributes - instance_methods.all
+    end
+
     class Attribute < Struct.new(:name)
       def parameters
         []

spec/bogus/fake_ar_attributes_spec.rb

@@ -14,8 +14,8 @@
   end
 
   class BlogPost < ActiveRecord::Base
-    def author
-      "#{self[:author]}!"
+    def author(x)
+      "#{x} #{self[:author]}!"
     end
   end
 
@@ -43,20 +43,12 @@ def author
     }.to raise_error(NameError)
   end
 
-  it "does not break the regular behavior of overwritten methods" do
-    post = BlogPost.new
+  it "does not overwrite existing method signatures" do
+    post = fake(:blog_post)
 
-    post.name = "hello world"
+    post.author("hello")
 
-    post.name.should == "hello world"
-  end
-
-  it "does not overwrite existing methods" do
-    post = BlogPost.new
-
-    post.author = "Batman"
-
-    post.author.should == "Batman!"
+    post.should have_received.author("hello")
   end
 
   class ExampleForActiveRecordAttributes