Always pass a format to the ActionView::Template constructor

This means we can eliminate nil checks and remove some mutations from
the `decorate` method.

2 files changed, 5 insertions, 3 deletions

diff --git a/actionview/test/abstract_unit.rb b/actionview/test/abstract_unit.rb
index b649b3c9dd..e0a1f59755 100644
--- a/actionview/test/abstract_unit.rb
+++ b/actionview/test/abstract_unit.rb
@@ -60,7 +60,7 @@ module RenderERBUtils
       string.strip,
       "test template",
       ActionView::Template.handler_for_extension(:erb),
-      {})
+      format: :html)
 
     view = ActionView::Base.with_empty_template_cache
     template.render(view.empty, {}).strip
diff --git a/actionview/test/template/template_test.rb b/actionview/test/template/template_test.rb
index a069c8f2d0..36caef28c2 100644
--- a/actionview/test/template/template_test.rb
+++ b/actionview/test/template/template_test.rb
@@ -38,7 +38,8 @@ class TestERBTemplate < ActiveSupport::TestCase
         "<%= @virtual_path %>",
         "partial",
         ERBHandler,
-        virtual_path: "partial"
+        virtual_path: "partial",
+        format: :html
       )
     end
 
@@ -55,7 +56,8 @@ class TestERBTemplate < ActiveSupport::TestCase
     end
   end
 
-  def new_template(body = "<%= hello %>", details = { format: :html })
+  def new_template(body = "<%= hello %>", details = {})
+    details = { format: :html }.merge details
     ActionView::Template.new(body.dup, "hello template", details.fetch(:handler) { ERBHandler }, { virtual_path: "hello" }.merge!(details))
   end