simple_format with blank wrapper_tag option returns nonsence HTML tag

[JunichiIto]

Steps to reproduce

Use simple_format method with blank wrapper_tag option.

simple_format(nil, {}, { wrapper_tag: "" })

Some people try to remove wrapper tag from the result of simple_format method, so they give an empty string to wrapper_tag option.

Expected behavior

It should fallback to p tag:

"<p></p>"

Or return no wrapper tags:

""

Or raise ArgumentError.

Actual behavior

It returns the following HTML:

"<></>"

But it is nonsense.

System configuration

Rails version: 7.0.2.3

Ruby version: 3.1.1

[akhilgkrishnan]

Made a partial fix in PR #49120 for handling the nil case. But as per the discussion #49120 (comment), we finally agreed to have validation in content_tag for handling different scenarios including the empty string "" case and raising an error.

I'm working on that and creating another PR handling the validation and raising an error for content_tag.