Add "new inputs can override the default input_html_classes" test case

test/inputs/discovery_test.rb

@@ -109,6 +109,14 @@ class DiscoveryTest < ActionView::TestCase
     end
   end
 
+  test 'new inputs can override the default input_html_classes' do
+    discovery do
+      with_form_for @user, :avatar, as: :file
+      assert_select 'form input[type=file]#user_avatar.file.file-upload', false
+      assert_select 'form input[type=file]#user_avatar.file-upload'
+    end
+  end
+
   test 'inputs method without wrapper_options are deprecated' do
     discovery do
       assert_deprecated do

test/support/discovery_inputs.rb

@@ -37,6 +37,13 @@ class CollectionSelectInput < SimpleForm::Inputs::CollectionSelectInput
   end
 end
 
+class FileInput < SimpleForm::Inputs::FileInput
+  def input_html_classes
+    super.delete_if { |html_class| html_class == 'file' }
+    super.push('file-upload')
+  end
+end
+
 module CustomInputs
   class CustomizedInput < SimpleForm::Inputs::StringInput
     def input_html_classes