1 files changed, 47 insertions, 4 deletions
diff --git a/activemodel/test/cases/model_test.rb b/activemodel/test/cases/model_test.rb
index 588d8e661e..ee0fa26546 100644
--- a/activemodel/test/cases/model_test.rb
+++ b/activemodel/test/cases/model_test.rb
@@ -3,7 +3,30 @@ require 'cases/helper'
 class ModelTest < ActiveModel::TestCase
   include ActiveModel::Lint::Tests
 
+  module DefaultValue
+    def self.included(klass)
+      klass.class_eval { attr_accessor :hello }
+    end
+
+    def initialize(*args)
+      @attr ||= 'default value'
+      super
+    end
+  end
+
   class BasicModel
+    include DefaultValue
+    include ActiveModel::Model
+    attr_accessor :attr
+  end
+
+  class BasicModelWithReversedMixins
+    include ActiveModel::Model
+    include DefaultValue
+    attr_accessor :attr
+  end
+
+  class SimpleModel
     include ActiveModel::Model
     attr_accessor :attr
   end
@@ -13,20 +36,40 @@ class ModelTest < ActiveModel::TestCase
   end
 
   def test_initialize_with_params
-    object = BasicModel.new(:attr => "value")
-    assert_equal object.attr, "value"
+    object = BasicModel.new(attr: "value")
+    assert_equal "value", object.attr
+  end
+
+  def test_initialize_with_params_and_mixins_reversed
+    object = BasicModelWithReversedMixins.new(attr: "value")
+    assert_equal "value", object.attr
   end
 
   def test_initialize_with_nil_or_empty_hash_params_does_not_explode
     assert_nothing_raised do
       BasicModel.new()
-      BasicModel.new nil
+      BasicModel.new(nil)
       BasicModel.new({})
+      SimpleModel.new(attr: 'value')
     end
   end
 
   def test_persisted_is_always_false
-    object = BasicModel.new(:attr => "value")
+    object = BasicModel.new(attr: "value")
     assert object.persisted? == false
   end
+
+  def test_mixin_inclusion_chain
+    object = BasicModel.new
+    assert_equal 'default value', object.attr
+  end
+
+  def test_mixin_initializer_when_args_exist
+    object = BasicModel.new(hello: 'world')
+    assert_equal 'world', object.hello
+  end
+
+  def test_mixin_initializer_when_args_dont_exist
+    assert_raises(NoMethodError) { SimpleModel.new(hello: 'world') }
+  end
 end