Attributes without values breaks the parser

[yatesco]

Hi,

I've noticed that the parser doesn't like <button readonly> but <button readonly=""> is fine. The error is: htmlElement.setAttribute(lowerName, emptyValue ? EMPTY.STR : value); in the following listing:

  // node_modules/diffhtml/dist/es/node/patch.js
  var { keys } = Object;
  var blocklist = /* @__PURE__ */ new Set();
  var allowlist = /* @__PURE__ */ new Set();
  var setAttribute = (vTree, domNode, name, value) => {
    const isObject = typeof value === "object" && value;
    const isFunction = typeof value === "function";
    const isSymbol = typeof value === "symbol";
    const isEvent = name.indexOf("on") === 0;
    const anyNode = domNode;
    const lowerName = isEvent ? name.toLowerCase() : name;
    const blocklistName = "s-" + vTree.nodeName + "-" + lowerName;
    const htmlElement = domNode;
    if (allowlist.has(blocklistName)) {
      anyNode[lowerName] = value;
    } else if (!blocklist.has(blocklistName)) {
      try {
        anyNode[lowerName] = value;
        allowlist.add(blocklistName);
      } catch {
        blocklist.add(blocklistName);
      }
    }
    if (!isObject && !isFunction && !isSymbol) {
      const emptyValue = value === null || value === void 0 || value === true;
      htmlElement.setAttribute(lowerName, emptyValue ? EMPTY.STR : value); <!-- HERE -->
    } else if (isObject && lowerName === "style") {
      const valueKeys = keys(value);
      for (let i = 0; i < valueKeys.length; i++) {
        htmlElement.style[valueKeys[i]] = value[valueKeys[i]];
      }
    }
  };
...

Unfortunately, this is from the bundled source code so I can't find the exact reference - I hope that's sufficient?

NOTE: it tends to fail on a descendant of a node with a valueless attribute, so in this case the child that failed was a grandchild of the element with a valueless attribute.

This bug report is all a bit messy - apologies - I'm on a time critical project ATM - I can return later (next week) with a reproducible project if that would help?

[tbranyen]

Sorry :( the old parser was based off node-fast-html-parser, and as such inherited some issues. I have this fixed in the new parser, but still playing whack-a-mole with existing tests. It's getting very close!

[yatesco]

No problem at all @tbranyen :-).

One critical bug/feature I use is the fact that it doesn't overwrite input fields if the page has newer data:

• now: input field = "abc"
• now+1 request latest from server
• now+2: input field = "abcdef"
• now+3 response from server, containing "input field=abc"
• now+4 merge complete

Crucially, the input field contains "abcdef" not the "abc" from the server. I rely on this, so can we please keep this behaviour (albeit behind a config option maybe?"

[tbranyen]

@yatesco I don't anticipate the behavior you're describing changing 👍