`href` should be an `attribute` rather than a `property`

[lukewestby]

When an a tag goes from having an href to having no href the patch leaves the attribute in place but with an empty string value instead of removing it. This is unexpected behavior, as a blank href has different semantics from no href at all. The cause of the behavior is that href is being set as a property, so a patch that removes it will set it to an empty string. Setting href as an attribute rather than a property should fix it.

Copying some context from https://github.com/elm-lang/virtual-dom/issues/109 below, including a link to an SSCCE

Problem

This bug is very easy to recreate and observe, I made a very basic ellie here

Long story short, here is what happens step-by-step:

1. Start with an a element with no href, like a [] [], it can't be clicked.
2. Toggle and switch to another a with an href like: a [ href "https://google.com" ] []
   • So far so good, we can now click the a and go to google.
3. Toggle back to an a with no href, but now instead of having the original a [] [] (which is what we expect) we get the following html: <a href="">no href</a>. This is obviously problematic.

Workaround

1. Use Html.Attributes.attribute "href" theHrefValue

[process-bot]

Thanks for the issue! Make sure it satisfies this checklist. My human colleagues will appreciate it!

Here is what to expect next, and if anyone wants to comment, keep these things in mind.

[amilner42]

Great workaround (and narrowing the problem) @lukewestby!

I can confirm it works for others who stumble into this issue.

[harfangk]

I just found out this issue too. I'm glad to see that it's already found and addressed!