Test transitions from differing value types for the same content binding.

[theengineear]

We’re missing some important edge-cases here in our test suite (some of which are real bugs). One example is switching content from an unsafeHTML updater to plain null or some such.

return html`${foo ? unsafeHTML(foo) : null}`

If the first time you render, foo is a markup string… and then the next time you render… foo is null… the engine won’t reset the DOM. And, in this case, you really want that DOM to get reset!

The fix is to add (and test) a simple method to determine if a DOM reset is required or not.