Fix: simple_format with blank wrapper_tag option returns plain html tag.

By default `simple_format` method returns the text wrapped with `<p>`. But if we explicitly specify
the `wrapper_tag: nil` in the options, it returns the text wrapped with `<></>` tag.

Before:
```ruby
 simple_format("Hello World", {},  { wrapper_tag: nil })
 # <>Hello World</>
```

After:
```ruby
 simple_format("Hello World", {},  { wrapper_tag: nil })
 # <p>Hello World</p>
```

Co-authored-by: Junichi Ito <jit@sonicgarden.jp>

actionview/CHANGELOG.md

@@ -1,3 +1,24 @@
+*   Fix `simple_format` with blank `wrapper_tag` option returns plain html tag
+
+    By default `simple_format` method returns the text wrapped with `<p>`. But if we explicitly specify
+    the `wrapper_tag: nil` in the options, it returns the text wrapped with `<></>` tag.
+
+    Before:
+
+    ```ruby
+    simple_format("Hello World", {},  { wrapper_tag: nil })
+    # <>Hello World</>
+    ```
+
+    After:
+
+    ```ruby
+    simple_format("Hello World", {},  { wrapper_tag: nil })
+    # <p>Hello World</p>
+    ```
+
+    *Akhil G Krishnan*, *Junichi Ito*
+
 *   Don't double-encode nested `field_id` and `field_name` index values
 
     Pass `index: @options` as a default keyword argument to `field_id` and

actionview/lib/action_view/helpers/text_helper.rb

@@ -320,7 +320,7 @@ module ActionView
       #   simple_format("<a target=\"_blank\" href=\"http://example.com\">Continue</a>", {}, { sanitize_options: { attributes: %w[target href] } })
       #   # => "<p><a target=\"_blank\" href=\"http://example.com\">Continue</a></p>"
       def simple_format(text, html_options = {}, options = {})
-        wrapper_tag = options.fetch(:wrapper_tag, :p)
+        wrapper_tag = options[:wrapper_tag] || "p"
 
         text = sanitize(text, options.fetch(:sanitize_options, {})) if options.fetch(:sanitize, true)
         paragraphs = split_paragraphs(text)

actionview/test/template/text_helper_test.rb

@@ -68,6 +68,7 @@ class TextHelperTest < ActionView::TestCase
 
   def test_simple_format_with_custom_wrapper
     assert_equal "<div></div>", simple_format(nil, {}, { wrapper_tag: "div" })
+    assert_equal "<p></p>", simple_format(nil, {}, { wrapper_tag: nil })
   end
 
   def test_simple_format_with_custom_wrapper_and_multi_line_breaks