templ errors if HTML attributes aren't quoted

[jvns]

Describe the bug

If I try run templ on this file:

package main

templ Hello() {
  <div id=main></div>
}

I get this error:

parsing error: <div>: malformed open element: line 3, col 7

Seems related to #116 / #125.

Expected behavior

<div id=main></div> is valid HTML (this post discusses how unquoted attributed values are valid), so I expected templ to compile it even if it's a little unusual.

That said I noticed that the Elements documentation page documents ways in which templ diverges from HTML ("Unlike HTML, templ requires that all HTML elements are closed..."), so if this is intentional it might be good to document it.

templ info output

(✓) os [ goos=darwin goarch=arm64 ]
(✓) go [ location=/opt/homebrew/bin/go version=go version go1.23.1 darwin/arm64 ]
(✓) gopls [ location=/Users/bork/go/bin/gopls version=golang.org/x/tools/gopls v0.8.4
    golang.org/x/tools/[email protected] h1:zGZsAXAb0LLws/Z+2BCWR17dkPHhIO2GYwYSSkeXX5c= ]
(✓) templ [ location=/Users/bork/go/bin/templ version=v0.2.778 ]

Desktop (please complete the following information):

• OS: Mac OS
• templ CLI version? v0.2.778
• Go version: 1.23
• gopls version: v0.8.4