Merge branch 'master' into fix_26964

15 files changed, 374 insertions, 278 deletions

diff --git a/actionview/test/abstract_unit.rb b/actionview/test/abstract_unit.rb
index 88c7189d22..5bc4151087 100644
--- a/actionview/test/abstract_unit.rb
+++ b/actionview/test/abstract_unit.rb
@@ -163,7 +163,7 @@ class ActionDispatch::IntegrationTest < ActiveSupport::TestCase
   # Stub Rails dispatcher so it does not get controller references and
   # simply return the controller#action as Rack::Body.
   class StubDispatcher < ::ActionDispatch::Routing::RouteSet::Dispatcher
-    protected
+    private
       def controller_reference(controller_param)
         controller_param
       end
diff --git a/actionview/test/activerecord/form_helper_activerecord_test.rb b/actionview/test/activerecord/form_helper_activerecord_test.rb
index 6152ec4720..0f7960b408 100644
--- a/actionview/test/activerecord/form_helper_activerecord_test.rb
+++ b/actionview/test/activerecord/form_helper_activerecord_test.rb
@@ -52,7 +52,7 @@ class FormHelperActiveRecordTest < ActionView::TestCase
     assert_dom_equal expected, output_buffer
   end
 
-  protected
+  private
 
     def hidden_fields(method = nil)
       txt = %{<input name="utf8" type="hidden" value="&#x2713;" />}
diff --git a/actionview/test/fixtures/test/test_template_with_delegation_reserved_keywords.erb b/actionview/test/fixtures/test/test_template_with_delegation_reserved_keywords.erb
new file mode 100644
index 0000000000..edfe52e422
--- /dev/null
+++ b/actionview/test/fixtures/test/test_template_with_delegation_reserved_keywords.erb
@@ -0,0 +1 @@
+<%= _ %> <%= arg %> <%= args %> <%= block %>
\ No newline at end of file
diff --git a/actionview/test/template/asset_tag_helper_test.rb b/actionview/test/template/asset_tag_helper_test.rb
index 3bdab42f7a..07a6452cc1 100644
--- a/actionview/test/template/asset_tag_helper_test.rb
+++ b/actionview/test/template/asset_tag_helper_test.rb
@@ -630,7 +630,7 @@ class AssetTagHelperNonVhostTest < ActionView::TestCase
   end
 
   def test_should_return_nothing_if_asset_host_isnt_configured
-    assert_equal nil, compute_asset_host("foo")
+    assert_nil compute_asset_host("foo")
   end
 
   def test_should_current_request_host_is_always_returned_for_request
diff --git a/actionview/test/template/capture_helper_test.rb b/actionview/test/template/capture_helper_test.rb
index 54bf9b4c33..7f37523eeb 100644
--- a/actionview/test/template/capture_helper_test.rb
+++ b/actionview/test/template/capture_helper_test.rb
@@ -127,18 +127,18 @@ class CaptureHelperTest < ActionView::TestCase
 
   def test_content_for_returns_nil_when_writing
     assert ! content_for?(:title)
-    assert_equal nil, content_for(:title, "foo")
-    assert_equal nil, content_for(:title) { output_buffer << "bar"; nil }
-    assert_equal nil, content_for(:title) { output_buffer << "  \n  "; nil }
+    assert_nil content_for(:title, "foo")
+    assert_nil content_for(:title) { output_buffer << "bar"; nil }
+    assert_nil content_for(:title) { output_buffer << "  \n  "; nil }
     assert_equal "foobar", content_for(:title)
-    assert_equal nil, content_for(:title, "foo", flush: true)
-    assert_equal nil, content_for(:title, flush: true) { output_buffer << "bar"; nil }
-    assert_equal nil, content_for(:title, flush: true) { output_buffer << "  \n  "; nil }
+    assert_nil content_for(:title, "foo", flush: true)
+    assert_nil content_for(:title, flush: true) { output_buffer << "bar"; nil }
+    assert_nil content_for(:title, flush: true) { output_buffer << "  \n  "; nil }
     assert_equal "bar", content_for(:title)
   end
 
   def test_content_for_returns_nil_when_content_missing
-    assert_equal nil, content_for(:some_missing_key)
+    assert_nil content_for(:some_missing_key)
   end
 
   def test_content_for_question_mark
diff --git a/actionview/test/template/compiled_templates_test.rb b/actionview/test/template/compiled_templates_test.rb
index 3ecac46d34..40ac867b38 100644
--- a/actionview/test/template/compiled_templates_test.rb
+++ b/actionview/test/template/compiled_templates_test.rb
@@ -24,6 +24,16 @@ class CompiledTemplatesTest < ActiveSupport::TestCase
     assert_equal locals.inspect, render(file: "test/render_file_inspect_local_assigns", locals: locals)
   end
 
+  def test_template_with_delegation_reserved_keywords
+    locals = {
+      _: "one",
+      arg: "two",
+      args: "three",
+      block: "four",
+    }
+    assert_equal "one two three four", render(file: "test/test_template_with_delegation_reserved_keywords", locals: locals)
+  end
+
   def test_template_with_unicode_identifier
     assert_equal "🎂", render(file: "test/render_file_unicode_local", locals: { 🎃: "🎂" })
   end
diff --git a/actionview/test/template/form_helper/form_with_test.rb b/actionview/test/template/form_helper/form_with_test.rb
index c80a2f61b9..3a91c7dce7 100644
--- a/actionview/test/template/form_helper/form_with_test.rb
+++ b/actionview/test/template/form_helper/form_with_test.rb
@@ -116,6 +116,16 @@ class FormWithActsLikeFormTagTest < FormWithTest
 
     assert_dom_equal expected, output_buffer
   end
+
+  def test_form_with_with_block_in_erb_and_local_true
+    output_buffer = render_erb("<%= form_with(url: 'http://www.example.com', local: true) do %>Hello world!<% end %>")
+
+    expected = whole_form("http://www.example.com", local: true) do
+      "Hello world!"
+    end
+
+    assert_dom_equal expected, output_buffer
+  end
 end
 
 class FormWithActsLikeFormForTest < FormWithTest
@@ -301,10 +311,10 @@ class FormWithActsLikeFormForTest < FormWithTest
 
     expected = whole_form("/posts/123", "create-post", method: "patch") do
       "<label for='post_title'>The Title</label>" +
-      "<input name='post[title]' type='text' id='post_title' value='Hello World' />" +
-      "<textarea name='post[body]' id='post_body'>\nBack to the hill and over it again!</textarea>" +
+      "<input name='post[title]' type='text' value='Hello World' />" +
+      "<textarea name='post[body]'>\nBack to the hill and over it again!</textarea>" +
       "<input name='post[secret]' type='hidden' value='0' />" +
-      "<input name='post[secret]' checked='checked' type='checkbox' id='post_secret' value='1' />" +
+      "<input name='post[secret]' checked='checked' type='checkbox' value='1' />" +
       "<input name='commit' data-disable-with='Create post' type='submit' value='Create post' />" +
       "<button name='button' type='submit'>Create post</button>" +
       "<button name='button' type='submit'><span>Create post</span></button>"
@@ -313,6 +323,75 @@ class FormWithActsLikeFormForTest < FormWithTest
     assert_dom_equal expected, output_buffer
   end
 
+  def test_form_with_only_url_on_create
+    form_with(url: "/posts") do |f|
+      concat f.label :title, "Label me"
+      concat f.text_field :title
+    end
+
+    expected = whole_form("/posts") do
+      '<label for="title">Label me</label>' +
+      '<input type="text" name="title">'
+    end
+
+    assert_dom_equal expected, output_buffer
+  end
+
+  def test_form_with_only_url_on_update
+    form_with(url: "/posts/123") do |f|
+      concat f.label :title, "Label me"
+      concat f.text_field :title
+    end
+
+    expected = whole_form("/posts/123") do
+      '<label for="title">Label me</label>' +
+      '<input type="text" name="title">'
+    end
+
+    assert_dom_equal expected, output_buffer
+  end
+
+  def test_form_with_general_attributes
+    form_with(url: "/posts/123") do |f|
+      concat f.text_field :no_model_to_back_this_badboy
+    end
+
+    expected = whole_form("/posts/123") do
+      '<input type="text" name="no_model_to_back_this_badboy">'
+    end
+
+    assert_dom_equal expected, output_buffer
+  end
+
+  def test_form_with_attribute_not_on_model
+    form_with(model: @post) do |f|
+      concat f.text_field :this_dont_exist_on_post
+    end
+
+    expected = whole_form("/posts/123", method: :patch) do
+      '<input type="text" name="post[this_dont_exist_on_post]">'
+    end
+
+    assert_dom_equal expected, output_buffer
+  end
+
+  def test_form_with_doesnt_call_private_or_protected_properties_on_form_object_skipping_value
+    obj = Class.new do
+      private def private_property
+        "That would be great."
+      end
+
+      protected def protected_property
+        "I believe you have my stapler."
+      end
+    end.new
+
+    form_with(model: obj, scope: "other_name", url: "/", id: "edit-other-name") do |f|
+      assert_dom_equal '<input type="hidden" name="other_name[private_property]">', f.hidden_field(:private_property)
+      assert_dom_equal '<input type="hidden" name="other_name[protected_property]">', f.hidden_field(:protected_property)
+    end
+  end
+
   def test_form_with_with_collection_radio_buttons
     post = Post.new
     def post.active; false; end
@@ -322,9 +401,9 @@ class FormWithActsLikeFormForTest < FormWithTest
 
     expected = whole_form("/posts") do
       "<input type='hidden' name='post[active]' value='' />" +
-      "<input id='post_active_true' name='post[active]' type='radio' value='true' />" +
+      "<input name='post[active]' type='radio' value='true' />" +
       "<label for='post_active_true'>true</label>" +
-      "<input checked='checked' id='post_active_false' name='post[active]' type='radio' value='false' />" +
+      "<input checked='checked' name='post[active]' type='radio' value='false' />" +
       "<label for='post_active_false'>false</label>"
     end
 
@@ -345,10 +424,10 @@ class FormWithActsLikeFormForTest < FormWithTest
     expected = whole_form("/posts") do
       "<input type='hidden' name='post[active]' value='' />" +
       "<label for='post_active_true'>" +
-      "<input id='post_active_true' name='post[active]' type='radio' value='true' />" +
+      "<input name='post[active]' type='radio' value='true' />" +
       "true</label>" +
       "<label for='post_active_false'>" +
-      "<input checked='checked' id='post_active_false' name='post[active]' type='radio' value='false' />" +
+      "<input checked='checked' name='post[active]' type='radio' value='false' />" +
       "false</label>"
     end
 
@@ -371,12 +450,12 @@ class FormWithActsLikeFormForTest < FormWithTest
     expected = whole_form("/posts") do
       "<input type='hidden' name='post[active]' value='' />" +
       "<label for='post_active_true'>" +
-      "<input id='post_active_true' name='post[active]' type='radio' value='true' />" +
+      "<input name='post[active]' type='radio' value='true' />" +
       "true</label>" +
       "<label for='post_active_false'>" +
-      "<input checked='checked' id='post_active_false' name='post[active]' type='radio' value='false' />" +
+      "<input checked='checked' name='post[active]' type='radio' value='false' />" +
       "false</label>" +
-      "<input id='post_id' name='post[id]' type='hidden' value='1' />"
+      "<input name='post[id]' type='hidden' value='1' />"
     end
 
     assert_dom_equal expected, output_buffer
@@ -392,9 +471,9 @@ class FormWithActsLikeFormForTest < FormWithTest
 
     expected = whole_form("/posts") do
       "<input type='hidden' name='post[1][active]' value='' />" +
-      "<input id='post_1_active_true' name='post[1][active]' type='radio' value='true' />" +
+      "<input name='post[1][active]' type='radio' value='true' />" +
       "<label for='post_1_active_true'>true</label>" +
-      "<input checked='checked' id='post_1_active_false' name='post[1][active]' type='radio' value='false' />" +
+      "<input checked='checked' name='post[1][active]' type='radio' value='false' />" +
       "<label for='post_1_active_false'>false</label>"
     end
 
@@ -411,11 +490,11 @@ class FormWithActsLikeFormForTest < FormWithTest
 
     expected = whole_form("/posts") do
       "<input name='post[tag_ids][]' type='hidden' value='' />" +
-      "<input checked='checked' id='post_tag_ids_1' name='post[tag_ids][]' type='checkbox' value='1' />" +
+      "<input checked='checked' name='post[tag_ids][]' type='checkbox' value='1' />" +
       "<label for='post_tag_ids_1'>Tag 1</label>" +
-      "<input id='post_tag_ids_2' name='post[tag_ids][]' type='checkbox' value='2' />" +
+      "<input name='post[tag_ids][]' type='checkbox' value='2' />" +
       "<label for='post_tag_ids_2'>Tag 2</label>" +
-      "<input checked='checked' id='post_tag_ids_3' name='post[tag_ids][]' type='checkbox' value='3' />" +
+      "<input checked='checked' name='post[tag_ids][]' type='checkbox' value='3' />" +
       "<label for='post_tag_ids_3'>Tag 3</label>"
     end
 
@@ -436,13 +515,13 @@ class FormWithActsLikeFormForTest < FormWithTest
     expected = whole_form("/posts") do
       "<input name='post[tag_ids][]' type='hidden' value='' />" +
       "<label for='post_tag_ids_1'>" +
-      "<input checked='checked' id='post_tag_ids_1' name='post[tag_ids][]' type='checkbox' value='1' />" +
+      "<input checked='checked' name='post[tag_ids][]' type='checkbox' value='1' />" +
       "Tag 1</label>" +
       "<label for='post_tag_ids_2'>" +
-      "<input id='post_tag_ids_2' name='post[tag_ids][]' type='checkbox' value='2' />" +
+      "<input name='post[tag_ids][]' type='checkbox' value='2' />" +
       "Tag 2</label>" +
       "<label for='post_tag_ids_3'>" +
-      "<input checked='checked' id='post_tag_ids_3' name='post[tag_ids][]' type='checkbox' value='3' />" +
+      "<input checked='checked' name='post[tag_ids][]' type='checkbox' value='3' />" +
       "Tag 3</label>"
     end
 
@@ -466,15 +545,15 @@ class FormWithActsLikeFormForTest < FormWithTest
     expected = whole_form("/posts") do
       "<input name='post[tag_ids][]' type='hidden' value='' />" +
       "<label for='post_tag_ids_1'>" +
-      "<input checked='checked' id='post_tag_ids_1' name='post[tag_ids][]' type='checkbox' value='1' />" +
+      "<input checked='checked' name='post[tag_ids][]' type='checkbox' value='1' />" +
       "Tag 1</label>" +
       "<label for='post_tag_ids_2'>" +
-      "<input id='post_tag_ids_2' name='post[tag_ids][]' type='checkbox' value='2' />" +
+      "<input name='post[tag_ids][]' type='checkbox' value='2' />" +
       "Tag 2</label>" +
       "<label for='post_tag_ids_3'>" +
-      "<input checked='checked' id='post_tag_ids_3' name='post[tag_ids][]' type='checkbox' value='3' />" +
+      "<input checked='checked' name='post[tag_ids][]' type='checkbox' value='3' />" +
       "Tag 3</label>" +
-      "<input id='post_id' name='post[id]' type='hidden' value='1' />"
+      "<input name='post[id]' type='hidden' value='1' />"
     end
 
     assert_dom_equal expected, output_buffer
@@ -491,7 +570,7 @@ class FormWithActsLikeFormForTest < FormWithTest
 
     expected = whole_form("/posts") do
       "<input name='post[1][tag_ids][]' type='hidden' value='' />" +
-      "<input checked='checked' id='post_1_tag_ids_1' name='post[1][tag_ids][]' type='checkbox' value='1' />" +
+      "<input checked='checked' name='post[1][tag_ids][]' type='checkbox' value='1' />" +
       "<label for='post_1_tag_ids_1'>Tag 1</label>"
     end
 
@@ -499,22 +578,18 @@ class FormWithActsLikeFormForTest < FormWithTest
   end
 
   def test_form_with_with_file_field_generate_multipart
-    Post.send :attr_accessor, :file
-
     form_with(model: @post, id: "create-post") do |f|
       concat f.file_field(:file)
     end
 
     expected = whole_form("/posts/123", "create-post", method: "patch", multipart: true) do
-      "<input name='post[file]' type='file' id='post_file' />"
+      "<input name='post[file]' type='file' />"
     end
 
     assert_dom_equal expected, output_buffer
   end
 
   def test_fields_with_file_field_generate_multipart
-    Comment.send :attr_accessor, :file
-
     form_with(model: @post) do |f|
       concat f.fields(:comment, model: @post) { |c|
         concat c.file_field(:file)
@@ -522,7 +597,7 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected = whole_form("/posts/123", method: "patch", multipart: true) do
-      "<input name='post[comment][file]' type='file' id='post_comment_file' />"
+      "<input name='post[comment][file]' type='file' />"
     end
 
     assert_dom_equal expected, output_buffer
@@ -561,7 +636,7 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected = whole_form("/posts/44", method: "patch") do
-      "<input name='post[title]' type='text' id='post_title' value='And his name will be forty and four.' />" +
+      "<input name='post[title]' type='text' value='And his name will be forty and four.' />" +
       "<input name='commit' data-disable-with='Edit post' type='submit' value='Edit post' />"
     end
 
@@ -579,28 +654,16 @@ class FormWithActsLikeFormForTest < FormWithTest
 
     expected = whole_form("/posts/123", "create-post", method: "patch") do
       "<label for='other_name_title' class='post_title'>Title</label>" +
-      "<input name='other_name[title]' id='other_name_title' value='Hello World' type='text' />" +
-      "<textarea name='other_name[body]' id='other_name_body'>\nBack to the hill and over it again!</textarea>" +
+      "<input name='other_name[title]' value='Hello World' type='text' />" +
+      "<textarea name='other_name[body]'>\nBack to the hill and over it again!</textarea>" +
       "<input name='other_name[secret]' value='0' type='hidden' />" +
-      "<input name='other_name[secret]' checked='checked' id='other_name_secret' value='1' type='checkbox' />" +
+      "<input name='other_name[secret]' checked='checked' value='1' type='checkbox' />" +
       "<input name='commit' value='Create post' data-disable-with='Create post' type='submit' />"
     end
 
     assert_dom_equal expected, output_buffer
   end
 
-  def test_form_tags_do_not_call_private_properties_on_form_object
-    obj = Class.new do
-      private def private_property
-        raise "This method should not be called."
-      end
-    end.new
-
-    form_with(model: obj, scope: "other_name", url: "/", id: "edit-other-name") do |f|
-      assert_raise(NoMethodError) { f.hidden_field(:private_property) }
-    end
-  end
-
   def test_form_with_with_method_as_part_of_html_options
     form_with(model: @post, url: "/", id: "create-post", html: { method: :delete }) do |f|
       concat f.text_field(:title)
@@ -609,10 +672,10 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected = whole_form("/", "create-post", method: "delete") do
-      "<input name='post[title]' type='text' id='post_title' value='Hello World' />" +
-      "<textarea name='post[body]' id='post_body'>\nBack to the hill and over it again!</textarea>" +
+      "<input name='post[title]' type='text' value='Hello World' />" +
+      "<textarea name='post[body]'>\nBack to the hill and over it again!</textarea>" +
       "<input name='post[secret]' type='hidden' value='0' />" +
-      "<input name='post[secret]' checked='checked' type='checkbox' id='post_secret' value='1' />"
+      "<input name='post[secret]' checked='checked' type='checkbox' value='1' />"
     end
 
     assert_dom_equal expected, output_buffer
@@ -626,10 +689,10 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected = whole_form("/", "create-post", method: "delete") do
-      "<input name='post[title]' type='text' id='post_title' value='Hello World' />" +
-      "<textarea name='post[body]' id='post_body'>\nBack to the hill and over it again!</textarea>" +
+      "<input name='post[title]' type='text' value='Hello World' />" +
+      "<textarea name='post[body]'>\nBack to the hill and over it again!</textarea>" +
       "<input name='post[secret]' type='hidden' value='0' />" +
-      "<input name='post[secret]' checked='checked' type='checkbox' id='post_secret' value='1' />"
+      "<input name='post[secret]' checked='checked' type='checkbox' value='1' />"
     end
 
     assert_dom_equal expected, output_buffer
@@ -643,7 +706,7 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected = whole_form("/search", "search-post", method: "get") do
-      "<input name='post[title]' type='search' id='post_title' />"
+      "<input name='post[title]' type='search' />"
     end
 
     assert_dom_equal expected, output_buffer
@@ -657,10 +720,10 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected = whole_form("/", "create-post", method: "patch") do
-      "<input name='post[title]' type='text' id='post_title' value='Hello World' />" +
-      "<textarea name='post[body]' id='post_body'>\nBack to the hill and over it again!</textarea>" +
+      "<input name='post[title]' type='text' value='Hello World' />" +
+      "<textarea name='post[body]'>\nBack to the hill and over it again!</textarea>" +
       "<input name='post[secret]' type='hidden' value='0' />" +
-      "<input name='post[secret]' checked='checked' type='checkbox' id='post_secret' value='1' />"
+      "<input name='post[secret]' checked='checked' type='checkbox' value='1' />"
     end
 
     assert_dom_equal expected, output_buffer
@@ -672,7 +735,7 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected = whole_form("/", skip_enforcing_utf8: true) do
-      "<input name='post[title]' type='text' id='post_title' value='Hello World' />"
+      "<input name='post[title]' type='text' value='Hello World' />"
     end
 
     assert_dom_equal expected, output_buffer
@@ -684,7 +747,7 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected = whole_form("/", skip_enforcing_utf8: false) do
-      "<input name='post[title]' type='text' id='post_title' value='Hello World' />"
+      "<input name='post[title]' type='text' value='Hello World' />"
     end
 
     assert_dom_equal expected, output_buffer
@@ -698,10 +761,10 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected = whole_form("/", "create-post") do
-      "<input name='post[title]' type='text' id='post_title' value='Hello World' />" +
-      "<textarea name='post[body]' id='post_body'>\nBack to the hill and over it again!</textarea>" +
+      "<input name='post[title]' type='text' value='Hello World' />" +
+      "<textarea name='post[body]'>\nBack to the hill and over it again!</textarea>" +
       "<input name='post[secret]' type='hidden' value='0' />" +
-      "<input name='post[secret]' checked='checked' type='checkbox' id='post_secret' value='1' />"
+      "<input name='post[secret]' checked='checked' type='checkbox' value='1' />"
     end
 
     assert_dom_equal expected, output_buffer
@@ -717,10 +780,10 @@ class FormWithActsLikeFormForTest < FormWithTest
 
     expected = whole_form("/posts/123", method: "patch") do
       "<label for='post_123_title'>Title</label>" +
-      "<input name='post[123][title]' type='text' id='post_123_title' value='Hello World' />" +
-      "<textarea name='post[123][body]' id='post_123_body'>\nBack to the hill and over it again!</textarea>" +
+      "<input name='post[123][title]' type='text' value='Hello World' />" +
+      "<textarea name='post[123][body]'>\nBack to the hill and over it again!</textarea>" +
       "<input name='post[123][secret]' type='hidden' value='0' />" +
-      "<input name='post[123][secret]' checked='checked' type='checkbox' id='post_123_secret' value='1' />"
+      "<input name='post[123][secret]' checked='checked' type='checkbox' value='1' />"
     end
 
     assert_dom_equal expected, output_buffer
@@ -734,10 +797,10 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected = whole_form("/posts/123", method: "patch") do
-      "<input name='post[][title]' type='text' id='post__title' value='Hello World' />" +
-      "<textarea name='post[][body]' id='post__body'>\nBack to the hill and over it again!</textarea>" +
+      "<input name='post[][title]' type='text' value='Hello World' />" +
+      "<textarea name='post[][body]'>\nBack to the hill and over it again!</textarea>" +
       "<input name='post[][secret]' type='hidden' value='0' />" +
-      "<input name='post[][secret]' checked='checked' type='checkbox' id='post__secret' value='1' />"
+      "<input name='post[][secret]' checked='checked' type='checkbox' value='1' />"
     end
 
     assert_dom_equal expected, output_buffer
@@ -752,7 +815,7 @@ class FormWithActsLikeFormForTest < FormWithTest
 
     expected = whole_form("/posts/123", method: "patch") do
       "<div class='field_with_errors'><label for='post_author_name' class='label'>Author name</label></div>" +
-      "<div class='field_with_errors'><input name='post[author_name]' type='text' id='post_author_name' value='' /></div>" +
+      "<div class='field_with_errors'><input name='post[author_name]' type='text' value='' /></div>" +
       "<input name='commit' data-disable-with='Create post' type='submit' value='Create post' />"
     end
 
@@ -770,7 +833,7 @@ class FormWithActsLikeFormForTest < FormWithTest
 
     expected = whole_form("/posts/123", method: "patch") do
       "<div class='field_with_errors'><label for='post_author_name' class='label'>Author name</label></div>" +
-      "<div class='field_with_errors'><input name='post[author_name]' type='text' id='post_author_name' value='' /></div>" +
+      "<div class='field_with_errors'><input name='post[author_name]' type='text' value='' /></div>" +
       "<input name='commit' data-disable-with='Create post' type='submit' value='Create post' />"
     end
 
@@ -800,10 +863,10 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected = whole_form("/posts/123", "namespace_edit_post_123", "edit_post", method: "patch") do
-      "<input name='post[title]' type='text' id='namespace_post_title' value='Hello World' />" +
-      "<textarea name='post[body]' id='namespace_post_body'>\nBack to the hill and over it again!</textarea>" +
+      "<input name='post[title]' type='text' value='Hello World' />" +
+      "<textarea name='post[body]'>\nBack to the hill and over it again!</textarea>" +
       "<input name='post[secret]' type='hidden' value='0' />" +
-      "<input name='post[secret]' checked='checked' type='checkbox' id='namespace_post_secret' value='1' />"
+      "<input name='post[secret]' checked='checked' type='checkbox' value='1' />"
     end
 
     assert_dom_equal expected, output_buffer
@@ -868,6 +931,40 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
   end
 
+  def test_fields_with_attributes_not_on_model
+    form_with(model: @post) do |f|
+      concat f.fields(:comment) { |c|
+        concat c.text_field :dont_exist_on_model
+      }
+    end
+
+    expected = whole_form("/posts/123", method: :patch) do
+      '<input type="text" name="post[comment][dont_exist_on_model]">'
+    end
+
+    assert_dom_equal expected, output_buffer
+  end
+
+  def test_fields_with_attributes_not_on_model_deep_nested
+    @comment.save
+    form_with(scope: :posts) do |f|
+      f.fields("post[]", model: @post) do |f2|
+        f2.text_field(:id)
+        @post.comments.each do |comment|
+          concat f2.fields("comment[]", model: comment) { |c|
+            concat c.text_field(:dont_exist_on_model)
+          }
+        end
+      end
+    end
+
+    expected = whole_form do
+      '<input name="posts[post][0][comment][1][dont_exist_on_model]" type="text">'
+    end
+
+    assert_dom_equal expected, output_buffer
+  end
+
   def test_nested_fields
     @comment.body = "Hello World"
     form_with(model: @post) do |f|
@@ -877,7 +974,7 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected = whole_form("/posts/123", method: "patch") do
-      "<input name='post[comment][body]' type='text' id='post_comment_body' value='Hello World' />"
+      "<input name='post[comment][body]' type='text' value='Hello World' />"
     end
 
     assert_dom_equal expected, output_buffer
@@ -897,7 +994,7 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected = whole_form do
-      "<input name='posts[post][0][comment][1][name]' type='text' id='posts_post_0_comment_1_name' value='comment #1' />"
+      "<input name='posts[post][0][comment][1][name]' type='text' value='comment #1' />"
     end
 
     assert_dom_equal expected, output_buffer
@@ -912,8 +1009,8 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected = whole_form("/posts/123", method: "patch") do
-      "<input name='post[123][title]' type='text' id='post_123_title' value='Hello World' />" +
-      "<input name='post[123][comment][][name]' type='text' id='post_123_comment__name' value='new comment' />"
+      "<input name='post[123][title]' type='text' value='Hello World' />" +
+      "<input name='post[123][comment][][name]' type='text' value='new comment' />"
     end
 
     assert_dom_equal expected, output_buffer
@@ -928,8 +1025,8 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected = whole_form("/posts/123", method: "patch") do
-      "<input name='post[1][title]' type='text' id='post_1_title' value='Hello World' />" +
-      "<input name='post[1][comment][1][name]' type='text' id='post_1_comment_1_name' value='new comment' />"
+      "<input name='post[1][title]' type='text' value='Hello World' />" +
+      "<input name='post[1][comment][1][name]' type='text' value='new comment' />"
     end
 
     assert_dom_equal expected, output_buffer
@@ -943,7 +1040,7 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected = whole_form("/posts/123", method: "patch") do
-      "<input name='post[1][comment][title]' type='text' id='post_1_comment_title' value='Hello World' />"
+      "<input name='post[1][comment][title]' type='text' value='Hello World' />"
     end
 
     assert_dom_equal expected, output_buffer
@@ -957,7 +1054,7 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected = whole_form("/posts/123", method: "patch") do
-      "<input name='post[1][comment][5][title]' type='text' id='post_1_comment_5_title' value='Hello World' />"
+      "<input name='post[1][comment][5][title]' type='text' value='Hello World' />"
     end
 
     assert_dom_equal expected, output_buffer
@@ -971,7 +1068,7 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected = whole_form("/posts/123", method: "patch") do
-      "<input name='post[123][comment][title]' type='text' id='post_123_comment_title' value='Hello World' />"
+      "<input name='post[123][comment][title]' type='text' value='Hello World' />"
     end
 
     assert_dom_equal expected, output_buffer
@@ -985,7 +1082,7 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected = whole_form("/posts/123", method: "patch") do
-      "<input name='post[comment][5][title]' type='radio' id='post_comment_5_title_hello' value='hello' />"
+      "<input name='post[comment][5][title]' type='radio' value='hello' />"
     end
 
     assert_dom_equal expected, output_buffer
@@ -999,7 +1096,7 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected = whole_form("/posts/123", method: "patch") do
-      "<input name='post[123][comment][123][title]' type='text' id='post_123_comment_123_title' value='Hello World' />"
+      "<input name='post[123][comment][123][title]' type='text' value='Hello World' />"
     end
 
     assert_dom_equal expected, output_buffer
@@ -1019,9 +1116,9 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected = whole_form("/posts/123", method: "patch") do
-      "<input name='post[123][comment][5][title]' type='text' id='post_123_comment_5_title' value='Hello World' />"
+      "<input name='post[123][comment][5][title]' type='text' value='Hello World' />"
     end + whole_form("/posts/123", method: "patch") do
-      "<input name='post[1][comment][123][title]' type='text' id='post_1_comment_123_title' value='Hello World' />"
+      "<input name='post[1][comment][123][title]' type='text' value='Hello World' />"
     end
 
     assert_dom_equal expected, output_buffer
@@ -1038,8 +1135,8 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected = whole_form("/posts/123", method: "patch") do
-      '<input name="post[title]" type="text" id="post_title" value="Hello World" />' +
-        '<input id="post_author_attributes_name" name="post[author_attributes][name]" type="text" value="new author" />'
+      '<input name="post[title]" type="text" value="Hello World" />' +
+        '<input name="post[author_attributes][name]" type="text" value="new author" />'
     end
 
     assert_dom_equal expected, output_buffer
@@ -1065,9 +1162,9 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected = whole_form("/posts/123", method: "patch") do
-      '<input name="post[title]" type="text" id="post_title" value="Hello World" />' +
-      '<input id="post_author_attributes_name" name="post[author_attributes][name]" type="text" value="author #321" />' +
-      '<input id="post_author_attributes_id" name="post[author_attributes][id]" type="hidden" value="321" />'
+      '<input name="post[title]" type="text" value="Hello World" />' +
+      '<input name="post[author_attributes][name]" type="text" value="author #321" />' +
+      '<input name="post[author_attributes][id]" type="hidden" value="321" />'
     end
 
     assert_dom_equal expected, output_buffer
@@ -1084,9 +1181,9 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected = whole_form("/posts/123", method: "patch") do
-      '<input name="post[title]" type="text" id="post_title" value="Hello World" />' +
-      '<input id="post_author_attributes_name" name="post[author_attributes][name]" type="text" value="author #321" />' +
-      '<input id="post_author_attributes_id" name="post[author_attributes][id]" type="hidden" value="321" />'
+      '<input name="post[title]" type="text" value="Hello World" />' +
+      '<input name="post[author_attributes][name]" type="text" value="author #321" />' +
+      '<input name="post[author_attributes][id]" type="hidden" value="321" />'
     end
 
     assert_dom_equal expected, output_buffer
@@ -1103,8 +1200,8 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected = whole_form("/posts/123", method: "patch") do
-      '<input name="post[title]" type="text" id="post_title" value="Hello World" />' +
-      '<input id="post_author_attributes_name" name="post[author_attributes][name]" type="text" value="author #321" />'
+      '<input name="post[title]" type="text" value="Hello World" />' +
+      '<input name="post[author_attributes][name]" type="text" value="author #321" />'
     end
 
     assert_dom_equal expected, output_buffer
@@ -1121,8 +1218,8 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected = whole_form("/posts/123", method: "patch") do
-      '<input name="post[title]" type="text" id="post_title" value="Hello World" />' +
-      '<input id="post_author_attributes_name" name="post[author_attributes][name]" type="text" value="author #321" />'
+      '<input name="post[title]" type="text" value="Hello World" />' +
+      '<input name="post[author_attributes][name]" type="text" value="author #321" />'
     end
 
     assert_dom_equal expected, output_buffer
@@ -1139,9 +1236,9 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected = whole_form("/posts/123", method: "patch") do
-      '<input name="post[title]" type="text" id="post_title" value="Hello World" />' +
-      '<input id="post_author_attributes_name" name="post[author_attributes][name]" type="text" value="author #321" />' +
-      '<input id="post_author_attributes_id" name="post[author_attributes][id]" type="hidden" value="321" />'
+      '<input name="post[title]" type="text" value="Hello World" />' +
+      '<input name="post[author_attributes][name]" type="text" value="author #321" />' +
+      '<input name="post[author_attributes][id]" type="hidden" value="321" />'
     end
 
     assert_dom_equal expected, output_buffer
@@ -1159,9 +1256,9 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected = whole_form("/posts/123", method: "patch") do
-      '<input name="post[title]" type="text" id="post_title" value="Hello World" />' +
-      '<input id="post_author_attributes_id" name="post[author_attributes][id]" type="hidden" value="321" />' +
-      '<input id="post_author_attributes_name" name="post[author_attributes][name]" type="text" value="author #321" />'
+      '<input name="post[title]" type="text" value="Hello World" />' +
+      '<input name="post[author_attributes][id]" type="hidden" value="321" />' +
+      '<input name="post[author_attributes][name]" type="text" value="author #321" />'
     end
 
     assert_dom_equal expected, output_buffer
@@ -1180,11 +1277,11 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected = whole_form("/posts/123", method: "patch") do
-      '<input name="post[title]" type="text" id="post_title" value="Hello World" />' +
-      '<input id="post_comments_attributes_0_name" name="post[comments_attributes][0][name]" type="text" value="comment #1" />' +
-      '<input id="post_comments_attributes_0_id" name="post[comments_attributes][0][id]" type="hidden" value="1" />' +
-      '<input id="post_comments_attributes_1_name" name="post[comments_attributes][1][name]" type="text" value="comment #2" />' +
-      '<input id="post_comments_attributes_1_id" name="post[comments_attributes][1][id]" type="hidden" value="2" />'
+      '<input name="post[title]" type="text" value="Hello World" />' +
+      '<input name="post[comments_attributes][0][name]" type="text" value="comment #1" />' +
+      '<input name="post[comments_attributes][0][id]" type="hidden" value="1" />' +
+      '<input name="post[comments_attributes][1][name]" type="text" value="comment #2" />' +
+      '<input name="post[comments_attributes][1][id]" type="hidden" value="2" />'
     end
 
     assert_dom_equal expected, output_buffer
@@ -1207,11 +1304,11 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected = whole_form("/posts/123", method: "patch") do
-      '<input name="post[title]" type="text" id="post_title" value="Hello World" />' +
-      '<input id="post_author_attributes_name" name="post[author_attributes][name]" type="text" value="author #321" />' +
-      '<input id="post_author_attributes_id" name="post[author_attributes][id]" type="hidden" value="321" />' +
-      '<input id="post_comments_attributes_0_name" name="post[comments_attributes][0][name]" type="text" value="comment #1" />' +
-      '<input id="post_comments_attributes_1_name" name="post[comments_attributes][1][name]" type="text" value="comment #2" />'
+      '<input name="post[title]" type="text" value="Hello World" />' +
+      '<input name="post[author_attributes][name]" type="text" value="author #321" />' +
+      '<input name="post[author_attributes][id]" type="hidden" value="321" />' +
+      '<input name="post[comments_attributes][0][name]" type="text" value="comment #1" />' +
+      '<input name="post[comments_attributes][1][name]" type="text" value="comment #2" />'
     end
 
     assert_dom_equal expected, output_buffer
@@ -1234,10 +1331,10 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected = whole_form("/posts/123", method: "patch") do
-      '<input name="post[title]" type="text" id="post_title" value="Hello World" />' +
-      '<input id="post_author_attributes_name" name="post[author_attributes][name]" type="text" value="author #321" />' +
-      '<input id="post_comments_attributes_0_name" name="post[comments_attributes][0][name]" type="text" value="comment #1" />' +
-      '<input id="post_comments_attributes_1_name" name="post[comments_attributes][1][name]" type="text" value="comment #2" />'
+      '<input name="post[title]" type="text" value="Hello World" />' +
+      '<input name="post[author_attributes][name]" type="text" value="author #321" />' +
+      '<input name="post[comments_attributes][0][name]" type="text" value="comment #1" />' +
+      '<input name="post[comments_attributes][1][name]" type="text" value="comment #2" />'
     end
 
     assert_dom_equal expected, output_buffer
@@ -1260,11 +1357,11 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected = whole_form("/posts/123", method: "patch") do
-      '<input name="post[title]" type="text" id="post_title" value="Hello World" />' +
-      '<input id="post_author_attributes_name" name="post[author_attributes][name]" type="text" value="author #321" />' +
-      '<input id="post_author_attributes_id" name="post[author_attributes][id]" type="hidden" value="321" />' +
-      '<input id="post_comments_attributes_0_name" name="post[comments_attributes][0][name]" type="text" value="comment #1" />' +
-      '<input id="post_comments_attributes_1_name" name="post[comments_attributes][1][name]" type="text" value="comment #2" />'
+      '<input name="post[title]" type="text" value="Hello World" />' +
+      '<input name="post[author_attributes][name]" type="text" value="author #321" />' +
+      '<input name="post[author_attributes][id]" type="hidden" value="321" />' +
+      '<input name="post[comments_attributes][0][name]" type="text" value="comment #1" />' +
+      '<input name="post[comments_attributes][1][name]" type="text" value="comment #2" />'
     end
 
     assert_dom_equal expected, output_buffer
@@ -1283,11 +1380,11 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected = whole_form("/posts/123", method: "patch") do
-      '<input name="post[title]" type="text" id="post_title" value="Hello World" />' +
-      '<input id="post_comments_attributes_0_name" name="post[comments_attributes][0][name]" type="text" value="comment #1" />' +
-      '<input id="post_comments_attributes_0_id" name="post[comments_attributes][0][id]" type="hidden" value="1" />' +
-      '<input id="post_comments_attributes_1_name" name="post[comments_attributes][1][name]" type="text" value="comment #2" />' +
-      '<input id="post_comments_attributes_1_id" name="post[comments_attributes][1][id]" type="hidden" value="2" />'
+      '<input name="post[title]" type="text" value="Hello World" />' +
+      '<input name="post[comments_attributes][0][name]" type="text" value="comment #1" />' +
+      '<input name="post[comments_attributes][0][id]" type="hidden" value="1" />' +
+      '<input name="post[comments_attributes][1][name]" type="text" value="comment #2" />' +
+      '<input name="post[comments_attributes][1][id]" type="hidden" value="2" />'
     end
 
     assert_dom_equal expected, output_buffer
@@ -1307,11 +1404,11 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected = whole_form("/posts/123", method: "patch") do
-      '<input name="post[title]" type="text" id="post_title" value="Hello World" />' +
-      '<input id="post_comments_attributes_0_id" name="post[comments_attributes][0][id]" type="hidden" value="1" />' +
-      '<input id="post_comments_attributes_0_name" name="post[comments_attributes][0][name]" type="text" value="comment #1" />' +
-      '<input id="post_comments_attributes_1_id" name="post[comments_attributes][1][id]" type="hidden" value="2" />' +
-      '<input id="post_comments_attributes_1_name" name="post[comments_attributes][1][name]" type="text" value="comment #2" />'
+      '<input name="post[title]" type="text" value="Hello World" />' +
+      '<input name="post[comments_attributes][0][id]" type="hidden" value="1" />' +
+      '<input name="post[comments_attributes][0][name]" type="text" value="comment #1" />' +
+      '<input name="post[comments_attributes][1][id]" type="hidden" value="2" />' +
+      '<input name="post[comments_attributes][1][name]" type="text" value="comment #2" />'
     end
 
     assert_dom_equal expected, output_buffer
@@ -1330,9 +1427,9 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected = whole_form("/posts/123", method: "patch") do
-      '<input name="post[title]" type="text" id="post_title" value="Hello World" />' +
-      '<input id="post_comments_attributes_0_name" name="post[comments_attributes][0][name]" type="text" value="new comment" />' +
-      '<input id="post_comments_attributes_1_name" name="post[comments_attributes][1][name]" type="text" value="new comment" />'
+      '<input name="post[title]" type="text" value="Hello World" />' +
+      '<input name="post[comments_attributes][0][name]" type="text" value="new comment" />' +
+      '<input name="post[comments_attributes][1][name]" type="text" value="new comment" />'
     end
 
     assert_dom_equal expected, output_buffer
@@ -1351,10 +1448,10 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected = whole_form("/posts/123", method: "patch") do
-      '<input name="post[title]" type="text" id="post_title" value="Hello World" />' +
-      '<input id="post_comments_attributes_0_name" name="post[comments_attributes][0][name]" type="text" value="comment #321" />' +
-      '<input id="post_comments_attributes_0_id" name="post[comments_attributes][0][id]" type="hidden" value="321" />' +
-      '<input id="post_comments_attributes_1_name" name="post[comments_attributes][1][name]" type="text" value="new comment" />'
+      '<input name="post[title]" type="text" value="Hello World" />' +
+      '<input name="post[comments_attributes][0][name]" type="text" value="comment #321" />' +
+      '<input name="post[comments_attributes][0][id]" type="hidden" value="321" />' +
+      '<input name="post[comments_attributes][1][name]" type="text" value="new comment" />'
     end
 
     assert_dom_equal expected, output_buffer
@@ -1369,7 +1466,7 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected = whole_form("/posts/123", method: "patch") do
-      '<input name="post[title]" type="text" id="post_title" value="Hello World" />'
+      '<input name="post[title]" type="text" value="Hello World" />'
     end
 
     assert_dom_equal expected, output_buffer
@@ -1386,11 +1483,11 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected = whole_form("/posts/123", method: "patch") do
-      '<input name="post[title]" type="text" id="post_title" value="Hello World" />' +
-      '<input id="post_comments_attributes_0_name" name="post[comments_attributes][0][name]" type="text" value="comment #1" />' +
-      '<input id="post_comments_attributes_0_id" name="post[comments_attributes][0][id]" type="hidden" value="1" />' +
-      '<input id="post_comments_attributes_1_name" name="post[comments_attributes][1][name]" type="text" value="comment #2" />' +
-      '<input id="post_comments_attributes_1_id" name="post[comments_attributes][1][id]" type="hidden" value="2" />'
+      '<input name="post[title]" type="text" value="Hello World" />' +
+      '<input name="post[comments_attributes][0][name]" type="text" value="comment #1" />' +
+      '<input name="post[comments_attributes][0][id]" type="hidden" value="1" />' +
+      '<input name="post[comments_attributes][1][name]" type="text" value="comment #2" />' +
+      '<input name="post[comments_attributes][1][id]" type="hidden" value="2" />'
     end
 
     assert_dom_equal expected, output_buffer
@@ -1407,11 +1504,11 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected = whole_form("/posts/123", method: "patch") do
-      '<input name="post[title]" type="text" id="post_title" value="Hello World" />' +
-      '<input id="post_comments_attributes_0_name" name="post[comments_attributes][0][name]" type="text" value="comment #1" />' +
-      '<input id="post_comments_attributes_0_id" name="post[comments_attributes][0][id]" type="hidden" value="1" />' +
-      '<input id="post_comments_attributes_1_name" name="post[comments_attributes][1][name]" type="text" value="comment #2" />' +
-      '<input id="post_comments_attributes_1_id" name="post[comments_attributes][1][id]" type="hidden" value="2" />'
+      '<input name="post[title]" type="text" value="Hello World" />' +
+      '<input name="post[comments_attributes][0][name]" type="text" value="comment #1" />' +
+      '<input name="post[comments_attributes][0][id]" type="hidden" value="1" />' +
+      '<input name="post[comments_attributes][1][name]" type="text" value="comment #2" />' +
+      '<input name="post[comments_attributes][1][id]" type="hidden" value="2" />'
     end
 
     assert_dom_equal expected, output_buffer
@@ -1442,11 +1539,11 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected = whole_form("/posts/123", method: "patch") do
-      '<input name="post[title]" type="text" id="post_title" value="Hello World" />' +
-      '<input id="post_comments_attributes_0_name" name="post[comments_attributes][0][name]" type="text" value="comment #1" />' +
-      '<input id="post_comments_attributes_0_id" name="post[comments_attributes][0][id]" type="hidden" value="1" />' +
-      '<input id="post_comments_attributes_1_name" name="post[comments_attributes][1][name]" type="text" value="comment #2" />' +
-      '<input id="post_comments_attributes_1_id" name="post[comments_attributes][1][id]" type="hidden" value="2" />'
+      '<input name="post[title]" type="text" value="Hello World" />' +
+      '<input name="post[comments_attributes][0][name]" type="text" value="comment #1" />' +
+      '<input name="post[comments_attributes][0][id]" type="hidden" value="1" />' +
+      '<input name="post[comments_attributes][1][name]" type="text" value="comment #2" />' +
+      '<input name="post[comments_attributes][1][id]" type="hidden" value="2" />'
     end
 
     assert_dom_equal expected, output_buffer
@@ -1465,10 +1562,10 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected = whole_form("/posts/123", method: "patch") do
-      '<input name="post[title]" type="text" id="post_title" value="Hello World" />' +
-      '<input id="post_comments_attributes_0_name" name="post[comments_attributes][0][name]" type="text" value="comment #321" />' +
-      '<input id="post_comments_attributes_0_id" name="post[comments_attributes][0][id]" type="hidden" value="321" />' +
-      '<input id="post_comments_attributes_1_name" name="post[comments_attributes][1][name]" type="text" value="new comment" />'
+      '<input name="post[title]" type="text" value="Hello World" />' +
+      '<input name="post[comments_attributes][0][name]" type="text" value="comment #321" />' +
+      '<input name="post[comments_attributes][0][id]" type="hidden" value="321" />' +
+      '<input name="post[comments_attributes][1][name]" type="text" value="new comment" />'
     end
 
     assert_dom_equal expected, output_buffer
@@ -1485,8 +1582,8 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected = whole_form("/posts/123", method: "patch") do
-      '<input id="post_comments_attributes_abc_name" name="post[comments_attributes][abc][name]" type="text" value="comment #321" />' +
-      '<input id="post_comments_attributes_abc_id" name="post[comments_attributes][abc][id]" type="hidden" value="321" />'
+      '<input name="post[comments_attributes][abc][name]" type="text" value="comment #321" />' +
+      '<input name="post[comments_attributes][abc][id]" type="hidden" value="321" />'
     end
 
     assert_dom_equal expected, output_buffer
@@ -1502,8 +1599,8 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected = whole_form("/posts/123", method: "patch") do
-      '<input id="post_comments_attributes_abc_name" name="post[comments_attributes][abc][name]" type="text" value="comment #321" />' +
-      '<input id="post_comments_attributes_abc_id" name="post[comments_attributes][abc][id]" type="hidden" value="321" />'
+      '<input name="post[comments_attributes][abc][name]" type="text" value="comment #321" />' +
+      '<input name="post[comments_attributes][abc][id]" type="hidden" value="321" />'
     end
 
     assert_dom_equal expected, output_buffer
@@ -1525,8 +1622,8 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected = whole_form("/posts/123", method: "patch") do
-      '<input id="post_comments_attributes_abc_name" name="post[comments_attributes][abc][name]" type="text" value="comment #321" />' +
-      '<input id="post_comments_attributes_abc_id" name="post[comments_attributes][abc][id]" type="hidden" value="321" />'
+      '<input name="post[comments_attributes][abc][name]" type="text" value="comment #321" />' +
+      '<input name="post[comments_attributes][abc][id]" type="hidden" value="321" />'
     end
 
     assert_dom_equal expected, output_buffer
@@ -1611,18 +1708,18 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected = whole_form("/posts/123", method: "patch") do
-      '<input id="post_comments_attributes_0_name" name="post[comments_attributes][0][name]" type="text" value="comment #321" />' +
-      '<input id="post_comments_attributes_0_relevances_attributes_0_value" name="post[comments_attributes][0][relevances_attributes][0][value]" type="text" value="commentrelevance #314" />' +
-      '<input id="post_comments_attributes_0_relevances_attributes_0_id" name="post[comments_attributes][0][relevances_attributes][0][id]" type="hidden" value="314" />' +
-      '<input id="post_comments_attributes_0_id" name="post[comments_attributes][0][id]" type="hidden" value="321" />' +
-      '<input id="post_tags_attributes_0_value" name="post[tags_attributes][0][value]" type="text" value="tag #123" />' +
-      '<input id="post_tags_attributes_0_relevances_attributes_0_value" name="post[tags_attributes][0][relevances_attributes][0][value]" type="text" value="tagrelevance #3141" />' +
-      '<input id="post_tags_attributes_0_relevances_attributes_0_id" name="post[tags_attributes][0][relevances_attributes][0][id]" type="hidden" value="3141" />' +
-      '<input id="post_tags_attributes_0_id" name="post[tags_attributes][0][id]" type="hidden" value="123" />' +
-      '<input id="post_tags_attributes_1_value" name="post[tags_attributes][1][value]" type="text" value="tag #456" />' +
-      '<input id="post_tags_attributes_1_relevances_attributes_0_value" name="post[tags_attributes][1][relevances_attributes][0][value]" type="text" value="tagrelevance #31415" />' +
-      '<input id="post_tags_attributes_1_relevances_attributes_0_id" name="post[tags_attributes][1][relevances_attributes][0][id]" type="hidden" value="31415" />' +
-      '<input id="post_tags_attributes_1_id" name="post[tags_attributes][1][id]" type="hidden" value="456" />'
+      '<input name="post[comments_attributes][0][name]" type="text" value="comment #321" />' +
+      '<input name="post[comments_attributes][0][relevances_attributes][0][value]" type="text" value="commentrelevance #314" />' +
+      '<input name="post[comments_attributes][0][relevances_attributes][0][id]" type="hidden" value="314" />' +
+      '<input name="post[comments_attributes][0][id]" type="hidden" value="321" />' +
+      '<input name="post[tags_attributes][0][value]" type="text" value="tag #123" />' +
+      '<input name="post[tags_attributes][0][relevances_attributes][0][value]" type="text" value="tagrelevance #3141" />' +
+      '<input name="post[tags_attributes][0][relevances_attributes][0][id]" type="hidden" value="3141" />' +
+      '<input name="post[tags_attributes][0][id]" type="hidden" value="123" />' +
+      '<input name="post[tags_attributes][1][value]" type="text" value="tag #456" />' +
+      '<input name="post[tags_attributes][1][relevances_attributes][0][value]" type="text" value="tagrelevance #31415" />' +
+      '<input name="post[tags_attributes][1][relevances_attributes][0][id]" type="hidden" value="31415" />' +
+      '<input name="post[tags_attributes][1][id]" type="hidden" value="456" />'
     end
 
     assert_dom_equal expected, output_buffer
@@ -1638,7 +1735,7 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected = whole_form("/posts/123", method: "patch") do
-      '<input id="post_author_attributes_name" name="post[author_attributes][name]" type="text" value="hash backed author" />'
+      '<input name="post[author_attributes][name]" type="text" value="hash backed author" />'
     end
 
     assert_dom_equal expected, output_buffer
@@ -1652,10 +1749,10 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected =
-      "<input name='post[title]' type='text' id='post_title' value='Hello World' />" +
-      "<textarea name='post[body]' id='post_body'>\nBack to the hill and over it again!</textarea>" +
+      "<input name='post[title]' type='text' value='Hello World' />" +
+      "<textarea name='post[body]'>\nBack to the hill and over it again!</textarea>" +
       "<input name='post[secret]' type='hidden' value='0' />" +
-      "<input name='post[secret]' checked='checked' type='checkbox' id='post_secret' value='1' />"
+      "<input name='post[secret]' checked='checked' type='checkbox' value='1' />"
 
     assert_dom_equal expected, output_buffer
   end
@@ -1668,10 +1765,10 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected =
-      "<input name='post[123][title]' type='text' id='post_123_title' value='Hello World' />" +
-      "<textarea name='post[123][body]' id='post_123_body'>\nBack to the hill and over it again!</textarea>" +
+      "<input name='post[123][title]' type='text' value='Hello World' />" +
+      "<textarea name='post[123][body]'>\nBack to the hill and over it again!</textarea>" +
       "<input name='post[123][secret]' type='hidden' value='0' />" +
-      "<input name='post[123][secret]' checked='checked' type='checkbox' id='post_123_secret' value='1' />"
+      "<input name='post[123][secret]' checked='checked' type='checkbox' value='1' />"
 
     assert_dom_equal expected, output_buffer
   end
@@ -1684,10 +1781,10 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected =
-      "<input name='post[][title]' type='text' id='post__title' value='Hello World' />" +
-      "<textarea name='post[][body]' id='post__body'>\nBack to the hill and over it again!</textarea>" +
+      "<input name='post[][title]' type='text' value='Hello World' />" +
+      "<textarea name='post[][body]'>\nBack to the hill and over it again!</textarea>" +
       "<input name='post[][secret]' type='hidden' value='0' />" +
-      "<input name='post[][secret]' checked='checked' type='checkbox' id='post__secret' value='1' />"
+      "<input name='post[][secret]' checked='checked' type='checkbox' value='1' />"
 
     assert_dom_equal expected, output_buffer
   end
@@ -1700,10 +1797,10 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected =
-      "<input name='post[abc][title]' type='text' id='post_abc_title' value='Hello World' />" +
-      "<textarea name='post[abc][body]' id='post_abc_body'>\nBack to the hill and over it again!</textarea>" +
+      "<input name='post[abc][title]' type='text' value='Hello World' />" +
+      "<textarea name='post[abc][body]'>\nBack to the hill and over it again!</textarea>" +
       "<input name='post[abc][secret]' type='hidden' value='0' />" +
-      "<input name='post[abc][secret]' checked='checked' type='checkbox' id='post_abc_secret' value='1' />"
+      "<input name='post[abc][secret]' checked='checked' type='checkbox' value='1' />"
 
     assert_dom_equal expected, output_buffer
   end
@@ -1716,10 +1813,10 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected =
-      "<input name='post[title]' type='text' id='post_title' value='Hello World' />" +
-      "<textarea name='post[body]' id='post_body'>\nBack to the hill and over it again!</textarea>" +
+      "<input name='post[title]' type='text' value='Hello World' />" +
+      "<textarea name='post[body]'>\nBack to the hill and over it again!</textarea>" +
       "<input name='post[secret]' type='hidden' value='0' />" +
-      "<input name='post[secret]' checked='checked' type='checkbox' id='post_secret' value='1' />"
+      "<input name='post[secret]' checked='checked' type='checkbox' value='1' />"
 
     assert_dom_equal expected, output_buffer
   end
@@ -1732,10 +1829,10 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected =
-      "<input name='post[title]' type='text' id='post_title' value='Hello World' />" +
-      "<textarea name='post[body]' id='post_body'>\nBack to the hill and over it again!</textarea>" +
+      "<input name='post[title]' type='text' value='Hello World' />" +
+      "<textarea name='post[body]'>\nBack to the hill and over it again!</textarea>" +
       "<input name='post[secret]' type='hidden' value='0' />" +
-      "<input name='post[secret]' checked='checked' type='checkbox' id='post_secret' value='1' />"
+      "<input name='post[secret]' checked='checked' type='checkbox' value='1' />"
 
     assert_dom_equal expected, output_buffer
   end
@@ -1747,7 +1844,7 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     assert_dom_equal "<label for=\"author_post_title\">Title</label>" +
-    "<input name='author[post][title]' type='text' id='author_post_title' value='Hello World' />",
+    "<input name='author[post][title]' type='text' value='Hello World' />",
       output_buffer
   end
 
@@ -1758,7 +1855,7 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     assert_dom_equal "<label for=\"author_post_1_title\">Title</label>" +
-      "<input name='author[post][1][title]' type='text' id='author_post_1_title' value='Hello World' />",
+      "<input name='author[post][1][title]' type='text' value='Hello World' />",
       output_buffer
   end
 
@@ -1777,10 +1874,10 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected = whole_form("/posts/123", "create-post", method: "patch") do
-      "<input name='post[title]' type='text' id='post_title' value='Hello World' />" +
-      "<textarea name='post[body]' id='post_body'>\nBack to the hill and over it again!</textarea>" +
+      "<input name='post[title]' type='text' value='Hello World' />" +
+      "<textarea name='post[body]'>\nBack to the hill and over it again!</textarea>" +
       "<input name='parent_post[secret]' type='hidden' value='0' />" +
-      "<input name='parent_post[secret]' checked='checked' type='checkbox' id='parent_post_secret' value='1' />"
+      "<input name='parent_post[secret]' checked='checked' type='checkbox' value='1' />"
     end
 
     assert_dom_equal expected, output_buffer
@@ -1797,9 +1894,9 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected = whole_form("/posts/123", "create-post", method: "patch") do
-      "<input name='post[title]' type='text' id='post_title' value='Hello World' />" +
-      "<textarea name='post[body]' id='post_body'>\nBack to the hill and over it again!</textarea>" +
-      "<input name='post[comment][name]' type='text' id='post_comment_name' value='new comment' />"
+      "<input name='post[title]' type='text' value='Hello World' />" +
+      "<textarea name='post[body]'>\nBack to the hill and over it again!</textarea>" +
+      "<input name='post[comment][name]' type='text' value='new comment' />"
     end
 
     assert_dom_equal expected, output_buffer
@@ -1813,7 +1910,7 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected = whole_form("/posts/123", method: "patch") do
-      "<input name='post[category][name]' type='text' id='post_category_name' />"
+      "<input name='post[category][name]' type='text' />"
     end
 
     assert_dom_equal expected, output_buffer
@@ -1837,9 +1934,9 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected = whole_form("/posts/123", method: "patch") do
-      "<label for='title'>Title:</label> <input name='post[title]' type='text' id='post_title' value='Hello World' /><br/>" +
-      "<label for='body'>Body:</label> <textarea name='post[body]' id='post_body'>\nBack to the hill and over it again!</textarea><br/>" +
-      "<label for='secret'>Secret:</label> <input name='post[secret]' type='hidden' value='0' /><input name='post[secret]' checked='checked' type='checkbox' id='post_secret' value='1' /><br/>"
+      "<label for='title'>Title:</label> <input name='post[title]' type='text' value='Hello World' /><br/>" +
+      "<label for='body'>Body:</label> <textarea name='post[body]'>\nBack to the hill and over it again!</textarea><br/>" +
+      "<label for='secret'>Secret:</label> <input name='post[secret]' type='hidden' value='0' /><input name='post[secret]' checked='checked' type='checkbox' value='1' /><br/>"
     end
 
     assert_dom_equal expected, output_buffer
@@ -1856,9 +1953,9 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected = whole_form("/posts/123", method: "patch") do
-      "<label for='title'>Title:</label> <input name='post[title]' type='text' id='post_title' value='Hello World' /><br/>" +
-      "<label for='body'>Body:</label> <textarea name='post[body]' id='post_body'>\nBack to the hill and over it again!</textarea><br/>" +
-      "<label for='secret'>Secret:</label> <input name='post[secret]' type='hidden' value='0' /><input name='post[secret]' checked='checked' type='checkbox' id='post_secret' value='1' /><br/>"
+      "<label for='title'>Title:</label> <input name='post[title]' type='text' value='Hello World' /><br/>" +
+      "<label for='body'>Body:</label> <textarea name='post[body]'>\nBack to the hill and over it again!</textarea><br/>" +
+      "<label for='secret'>Secret:</label> <input name='post[secret]' type='hidden' value='0' /><input name='post[secret]' checked='checked' type='checkbox' value='1' /><br/>"
     end
 
     assert_dom_equal expected, output_buffer
@@ -1875,7 +1972,7 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected = whole_form("/posts/123", method: "patch") do
-      "<label for='title'>Title:</label> <input name='post[title]' type='text' id='post_title' value='Hello World' /><br/>"
+      "<label for='title'>Title:</label> <input name='post[title]' type='text' value='Hello World' /><br/>"
     end
 
     assert_dom_equal expected, output_buffer
@@ -1890,7 +1987,7 @@ class FormWithActsLikeFormForTest < FormWithTest
       concat f.text_field(:title)
     end
 
-    expected = "<label for='title'>Title:</label> <input name='post[title]' type='text' id='post_title' value='Hello World' /><br/>"
+    expected = "<label for='title'>Title:</label> <input name='post[title]' type='text' value='Hello World' /><br/>"
 
     assert_dom_equal expected, output_buffer
   end
@@ -1902,7 +1999,7 @@ class FormWithActsLikeFormForTest < FormWithTest
       concat f.text_field(:title)
     end
 
-    expected = "<label for='title'>Title:</label> <input name='post[title]' type='text' id='post_title' value='Hello World' /><br/>"
+    expected = "<label for='title'>Title:</label> <input name='post[title]' type='text' value='Hello World' /><br/>"
 
     assert_dom_equal expected, output_buffer
   end
@@ -1915,9 +2012,9 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
 
     expected =
-      "<label for='title'>Title:</label> <input name='post[title]' type='text' id='post_title' value='Hello World' /><br/>" +
-      "<label for='body'>Body:</label> <textarea name='post[body]' id='post_body'>\nBack to the hill and over it again!</textarea><br/>" +
-      "<label for='secret'>Secret:</label> <input name='post[secret]' type='hidden' value='0' /><input name='post[secret]' checked='checked' type='checkbox' id='post_secret' value='1' /><br/>"
+      "<label for='title'>Title:</label> <input name='post[title]' type='text' value='Hello World' /><br/>" +
+      "<label for='body'>Body:</label> <textarea name='post[body]'>\nBack to the hill and over it again!</textarea><br/>" +
+      "<label for='secret'>Secret:</label> <input name='post[secret]' type='hidden' value='0' /><input name='post[secret]' checked='checked' type='checkbox' value='1' /><br/>"
 
     assert_dom_equal expected, output_buffer
   end
@@ -2086,7 +2183,7 @@ class FormWithActsLikeFormForTest < FormWithTest
     assert_equal 1, initialization_count, "form builder instantiated more than once"
   end
 
-  protected
+  private
     def hidden_fields(options = {})
       method = options[:method]
 
diff --git a/actionview/test/template/form_helper_test.rb b/actionview/test/template/form_helper_test.rb
index 022bf315ce..2bc0434771 100644
--- a/actionview/test/template/form_helper_test.rb
+++ b/actionview/test/template/form_helper_test.rb
@@ -1751,8 +1751,6 @@ class FormHelperTest < ActionView::TestCase
   end
 
   def test_form_for_with_file_field_generate_multipart
-    Post.send :attr_accessor, :file
-
     form_for(@post, html: { id: "create-post" }) do |f|
       concat f.file_field(:file)
     end
@@ -1765,8 +1763,6 @@ class FormHelperTest < ActionView::TestCase
   end
 
   def test_fields_for_with_file_field_generate_multipart
-    Comment.send :attr_accessor, :file
-
     form_for(@post) do |f|
       concat f.fields_for(:comment, @post) { |c|
         concat c.file_field(:file)
@@ -1833,9 +1829,9 @@ class FormHelperTest < ActionView::TestCase
     obj = Class.new do
       private
 
-      def private_property
-        raise "This method should not be called."
-      end
+        def private_property
+          raise "This method should not be called."
+        end
     end.new
 
     form_for(obj, as: "other_name", url: "/", html: { id: "edit-other-name" }) do |f|
@@ -2266,11 +2262,13 @@ class FormHelperTest < ActionView::TestCase
       concat f.fields_for("comment[]", @comment) { |c|
         concat c.text_field(:name)
       }
+      concat f.text_field(:body)
     end
 
     expected = whole_form("/posts/123", "edit_post[]", "edit_post[]", method: "patch") do
       "<input name='post[123][title]' type='text' id='post_123_title' value='Hello World' />" +
-      "<input name='post[123][comment][][name]' type='text' id='post_123_comment__name' value='new comment' />"
+      "<input name='post[123][comment][][name]' type='text' id='post_123_comment__name' value='new comment' />" +
+      "<input name='post[123][body]' type='text' id='post_123_body' value='Back to the hill and over it again!' />"
     end
 
     assert_dom_equal expected, output_buffer
@@ -3443,7 +3441,7 @@ class FormHelperTest < ActionView::TestCase
     assert_equal 1, initialization_count, "form builder instantiated more than once"
   end
 
-  protected
+  private
 
     def hidden_fields(options = {})
       method = options[:method]
diff --git a/actionview/test/template/form_tag_helper_test.rb b/actionview/test/template/form_tag_helper_test.rb
index 24ae6b8b90..1248a0bb09 100644
--- a/actionview/test/template/form_tag_helper_test.rb
+++ b/actionview/test/template/form_tag_helper_test.rb
@@ -694,31 +694,31 @@ class FormTagHelperTest < ActionView::TestCase
   def test_text_area_tag_options_symbolize_keys_side_effects
     options = { option: "random_option" }
     text_area_tag "body", "hello world", options
-    assert_equal options, option: "random_option"
+    assert_equal({ option: "random_option" }, options)
   end
 
   def test_submit_tag_options_symbolize_keys_side_effects
     options = { option: "random_option" }
     submit_tag "submit value", options
-    assert_equal options, option: "random_option"
+    assert_equal({ option: "random_option" }, options)
   end
 
   def test_button_tag_options_symbolize_keys_side_effects
     options = { option: "random_option" }
     button_tag "button value", options
-    assert_equal options, option: "random_option"
+    assert_equal({ option: "random_option" }, options)
   end
 
   def test_image_submit_tag_options_symbolize_keys_side_effects
     options = { option: "random_option" }
     image_submit_tag "submit source", options
-    assert_equal options, option: "random_option"
+    assert_equal({ option: "random_option" }, options)
   end
 
   def test_image_label_tag_options_symbolize_keys_side_effects
     options = { option: "random_option" }
     label_tag "submit source", "title", options
-    assert_equal options, option: "random_option"
+    assert_equal({ option: "random_option" }, options)
   end
 
   def protect_against_forgery?
diff --git a/actionview/test/template/number_helper_test.rb b/actionview/test/template/number_helper_test.rb
index 2a2ada2b36..678120a9c9 100644
--- a/actionview/test/template/number_helper_test.rb
+++ b/actionview/test/template/number_helper_test.rb
@@ -4,7 +4,7 @@ class NumberHelperTest < ActionView::TestCase
   tests ActionView::Helpers::NumberHelper
 
   def test_number_to_phone
-    assert_equal nil, number_to_phone(nil)
+    assert_nil number_to_phone(nil)
     assert_equal "555-1234", number_to_phone(5551234)
     assert_equal "(800) 555-1212 x 123", number_to_phone(8005551212, area_code: true, extension: 123)
     assert_equal "+18005551212", number_to_phone(8005551212, country_code: 1, delimiter: "")
@@ -13,7 +13,7 @@ class NumberHelperTest < ActionView::TestCase
   end
 
   def test_number_to_currency
-    assert_equal nil, number_to_currency(nil)
+    assert_nil number_to_currency(nil)
     assert_equal "$1,234,567,890.50", number_to_currency(1234567890.50)
     assert_equal "$1,234,567,892", number_to_currency(1234567891.50, precision: 0)
     assert_equal "1,234,567,890.50 - K&#269;", number_to_currency("-1234567890.50", unit: raw("K&#269;"), format: "%n %u", negative_format: "%n - %u")
@@ -25,7 +25,7 @@ class NumberHelperTest < ActionView::TestCase
   end
 
   def test_number_to_percentage
-    assert_equal nil, number_to_percentage(nil)
+    assert_nil number_to_percentage(nil)
     assert_equal "100.000%", number_to_percentage(100)
     assert_equal "100.000 %", number_to_percentage(100, format: "%n %")
     assert_equal "&lt;b&gt;100.000&lt;/b&gt; %", number_to_percentage(100, format: "<b>%n</b> %")
@@ -43,13 +43,13 @@ class NumberHelperTest < ActionView::TestCase
   end
 
   def test_number_with_delimiter
-    assert_equal nil, number_with_delimiter(nil)
+    assert_nil number_with_delimiter(nil)
     assert_equal "12,345,678", number_with_delimiter(12345678)
     assert_equal "0", number_with_delimiter(0)
   end
 
   def test_number_with_precision
-    assert_equal nil, number_with_precision(nil)
+    assert_nil number_with_precision(nil)
     assert_equal "-111.235", number_with_precision(-111.2346)
     assert_equal "111.00", number_with_precision(111, precision: 2)
     assert_equal "0.00100", number_with_precision(0.001, precision: 5)
@@ -57,13 +57,13 @@ class NumberHelperTest < ActionView::TestCase
   end
 
   def test_number_to_human_size
-    assert_equal nil, number_to_human_size(nil)
+    assert_nil number_to_human_size(nil)
     assert_equal "3 Bytes", number_to_human_size(3.14159265)
     assert_equal "1.2 MB", number_to_human_size(1234567, precision: 2)
   end
 
   def test_number_to_human
-    assert_equal nil,   number_to_human(nil)
+    assert_nil number_to_human(nil)
     assert_equal "0",   number_to_human(0)
     assert_equal "1.23 Thousand", number_to_human(1234)
     assert_equal "489.0 Thousand", number_to_human(489000, precision: 4, strip_insignificant_zeros: false)
diff --git a/actionview/test/template/test_case_test.rb b/actionview/test/template/test_case_test.rb
index 41225000f0..3deddd5706 100644
--- a/actionview/test/template/test_case_test.rb
+++ b/actionview/test/template/test_case_test.rb
@@ -50,7 +50,7 @@ module ActionView
     end
 
     test "retrieve non existing config values" do
-      assert_equal nil, ActionView::Base.new.config.something_odd
+      assert_nil ActionView::Base.new.config.something_odd
     end
 
     test "works without testing a helper module" do
diff --git a/actionview/test/template/text_test.rb b/actionview/test/template/text_test.rb
index 6510688f97..ee526dc367 100644
--- a/actionview/test/template/text_test.rb
+++ b/actionview/test/template/text_test.rb
@@ -1,17 +1,7 @@
 require "abstract_unit"
 
 class TextTest < ActiveSupport::TestCase
-  test "formats returns symbol for recognized MIME type" do
-    assert_equal [:text], ActionView::Template::Text.new("", :text).formats
-  end
-
-  test "formats returns string for recognized MIME type when MIME does not have symbol" do
-    foo = Mime::Type.lookup("foo")
-    assert_nil foo.to_sym
-    assert_equal ["foo"], ActionView::Template::Text.new("", foo).formats
-  end
-
-  test "formats returns string for unknown MIME type" do
-    assert_equal ["foo"], ActionView::Template::Text.new("", "foo").formats
+  test "formats always return :text" do
+    assert_equal [:text], ActionView::Template::Text.new("").formats
   end
 end
diff --git a/actionview/test/template/url_helper_test.rb b/actionview/test/template/url_helper_test.rb
index 5a2319fe96..1e64385b52 100644
--- a/actionview/test/template/url_helper_test.rb
+++ b/actionview/test/template/url_helper_test.rb
@@ -810,7 +810,7 @@ class TasksController < ActionController::Base
     render_default
   end
 
-  protected
+  private
     def render_default
       render inline: "<%= link_to_unless_current('tasks', tasks_path) %>\n" +
         "<%= link_to_unless_current('tasks', tasks_url) %>"
diff --git a/actionview/test/ujs/config.ru b/actionview/test/ujs/config.ru
index cb961dc140..414c2063c3 100644
--- a/actionview/test/ujs/config.ru
+++ b/actionview/test/ujs/config.ru
@@ -1,3 +1,3 @@
-$LOAD_PATH.unshift File.expand_path('..', __FILE__)
-require 'server'
+$LOAD_PATH.unshift File.expand_path("..", __FILE__)
+require "server"
 run UJS::Server
diff --git a/actionview/test/ujs/server.rb b/actionview/test/ujs/server.rb
index c7698c87fa..25f70baf5f 100644
--- a/actionview/test/ujs/server.rb
+++ b/actionview/test/ujs/server.rb
@@ -12,7 +12,7 @@ module UJS
       get "/rails-ujs.js" => Blade::Assets.environment
       get "/" => "tests#index"
       match "/echo" => "tests#echo", via: :all
-      get "/error" => proc {|env| [403, {}, []] }
+      get "/error" => proc { |env| [403, {}, []] }
     end
 
     config.cache_classes = false
@@ -26,7 +26,7 @@ module UJS
 end
 
 module TestsHelper
-  def jquery_link version
+  def jquery_link(version)
     if params[:version] == version
       "[#{version}]"
     else
@@ -34,7 +34,7 @@ module TestsHelper
     end
   end
 
-  def cdn_link cdn
+  def cdn_link(cdn)
     if params[:cdn] == cdn
       "[#{cdn}]"
     else
@@ -43,22 +43,22 @@ module TestsHelper
   end
 
   def jquery_src
-    if params[:version] == 'edge'
+    if params[:version] == "edge"
       "/vendor/jquery.js"
-    elsif params[:cdn] && params[:cdn] == 'googleapis'
+    elsif params[:cdn] && params[:cdn] == "googleapis"
       "https://ajax.googleapis.com/ajax/libs/jquery/#{params[:version]}/jquery.min.js"
     else
       "http://code.jquery.com/jquery-#{params[:version]}.js"
     end
   end
 
-  def test_to *names
+  def test_to(*names)
     names = ["/vendor/qunit.js", "settings"] + names
     names.map { |name| script_tag name }.join("\n").html_safe
   end
 
-  def script_tag src
-    src = "/test/#{src}.js" unless src.index('/')
+  def script_tag(src)
+    src = "/test/#{src}.js" unless src.index("/")
     %(<script src="#{src}" type="text/javascript"></script>).html_safe
   end
 
@@ -72,20 +72,20 @@ class TestsController < ActionController::Base
   layout "application"
 
   def index
-    params[:version] ||= ENV['JQUERY_VERSION'] || '1.11.0'
-    params[:cdn] ||= 'jquery'
+    params[:version] ||= ENV["JQUERY_VERSION"] || "1.11.0"
+    params[:cdn] ||= "jquery"
     render :index
   end
 
   def echo
-    data = { :params => params.to_unsafe_h }.update(request.env)
+    data = { params: params.to_unsafe_h }.update(request.env)
 
-    if params[:content_type] and params[:content]
+    if params[:content_type] && params[:content]
       render inline: params[:content], content_type: params[:content_type]
     elsif request.xhr?
       render json: JSON.generate(data)
     elsif params[:iframe]
-      payload = JSON.generate(data).gsub('<', '&lt;').gsub('>', '&gt;')
+      payload = JSON.generate(data).gsub("<", "&lt;").gsub(">", "&gt;")
       html = <<-HTML
         <script>
           if (window.top && window.top !== window)
@@ -96,7 +96,7 @@ class TestsController < ActionController::Base
 
       render html: html.html_safe
     else
-      render text: "ERROR: #{request.path} requested without ajax", status: 404
+      render plain: "ERROR: #{request.path} requested without ajax", status: 404
     end
   end
 end