3 files changed, 36 insertions, 0 deletions
diff --git a/actionpack/CHANGELOG.md b/actionpack/CHANGELOG.md
index 44b8fa843d..6ea7276ac6 100644
--- a/actionpack/CHANGELOG.md
+++ b/actionpack/CHANGELOG.md
@@ -1,3 +1,7 @@
+*   Fix `assert_template` not being able to assert that no files were rendered.
+
+    *Guo Xiang Tan*
+
 *   Extract source code for the entire exception stack trace for
     better debugging and diagnosis.
 
diff --git a/actionpack/lib/action_controller/test_case.rb b/actionpack/lib/action_controller/test_case.rb
index eb5d824cbc..152420a54c 100644
--- a/actionpack/lib/action_controller/test_case.rb
+++ b/actionpack/lib/action_controller/test_case.rb
@@ -91,6 +91,13 @@ module ActionController
     #   # assert that no partials were rendered
     #   assert_template partial: false
     #
+    #   # assert that a file was rendered
+    #   assert_template file: "README.rdoc"
+    #
+    #   # assert that no file was rendered
+    #   assert_template file: nil
+    #   assert_template file: false
+    #
     # In a view test case, you can also assert that specific locals are passed
     # to partials:
     #
@@ -140,6 +147,8 @@ module ActionController
 
         if options[:file]
           assert_includes @_files.keys, options[:file]
+        elsif options.key?(:file)
+          assert @_files.blank?, "expected no files but #{@_files.keys} was rendered"
         end
 
         if expected_partial = options[:partial]
diff --git a/actionpack/test/controller/action_pack_assertions_test.rb b/actionpack/test/controller/action_pack_assertions_test.rb
index b6b5a218cc..311302819e 100644
--- a/actionpack/test/controller/action_pack_assertions_test.rb
+++ b/actionpack/test/controller/action_pack_assertions_test.rb
@@ -488,6 +488,11 @@ class AssertTemplateTest < ActionController::TestCase
     assert_raise(ActiveSupport::TestCase::Assertion) do
       assert_template :file => 'test/hello_world'
     end
+
+    get :render_file_absolute_path
+    assert_raise(ActiveSupport::TestCase::Assertion) do
+      assert_template file: nil
+    end
   end
 
   def test_with_nil_passes_when_no_template_rendered
@@ -612,6 +617,24 @@ class AssertTemplateTest < ActionController::TestCase
 
     get :nothing
     assert_template nil
+
+    get :partial
+    assert_template partial: 'test/_partial'
+
+    get :nothing
+    assert_template partial: nil
+
+    get :render_with_layout
+    assert_template layout: 'layouts/standard'
+
+    get :nothing
+    assert_template layout: nil
+
+    get :render_file_relative_path
+    assert_template file: 'README.rdoc'
+
+    get :nothing
+    assert_template file: nil
   end
 end