made dynamic finders alias_attribute aware

previously dynamic finders only worked in combination with the actual
column name and not its alias defined with #alias_attribute

2 files changed, 12 insertions, 1 deletions

diff --git a/activemodel/lib/active_model/attribute_methods.rb b/activemodel/lib/active_model/attribute_methods.rb
index b5b50847c2..30f51e041f 100644
--- a/activemodel/lib/active_model/attribute_methods.rb
+++ b/activemodel/lib/active_model/attribute_methods.rb
@@ -61,7 +61,8 @@ module ActiveModel
     CALL_COMPILABLE_REGEXP = /\A[a-zA-Z_]\w*[!?]?\z/
 
     included do
-      class_attribute :attribute_method_matchers, instance_writer: false
+      class_attribute :attribute_aliases, :attribute_method_matchers, instance_writer: false
+      self.attribute_aliases = {}
       self.attribute_method_matchers = [ClassMethods::AttributeMethodMatcher.new]
     end
 
@@ -192,6 +193,7 @@ module ActiveModel
       #   person.nickname # => "Bob"
       #   person.name     # => "Bob"
       def alias_attribute(new_name, old_name)
+        self.attribute_aliases = attribute_aliases.merge(new_name.to_s => old_name.to_s)
         attribute_method_matchers.each do |matcher|
           matcher_new = matcher.method_name(new_name).to_s
           matcher_old = matcher.method_name(old_name).to_s
diff --git a/activemodel/test/cases/attribute_methods_test.rb b/activemodel/test/cases/attribute_methods_test.rb
index e2f2cecc09..baaf842222 100644
--- a/activemodel/test/cases/attribute_methods_test.rb
+++ b/activemodel/test/cases/attribute_methods_test.rb
@@ -154,6 +154,15 @@ class AttributeMethodsTest < ActiveModel::TestCase
     assert_equal "value of foo", ModelWithAttributes.new.foo
   end
 
+  test '#alias_attribute generates attribute_aliases lookup hash' do
+    klass = Class.new(ModelWithAttributes) do
+      define_attribute_methods :foo
+      alias_attribute :bar, :foo
+    end
+
+    assert_equal({ "bar" => "foo" }, klass.attribute_aliases)
+  end
+
   test '#define_attribute_methods generates attribute methods with spaces in their names' do
     ModelWithAttributesWithSpaces.define_attribute_methods(:'foo bar')