I asked ChatGPT whether to be a hardass about item-level guids

[scripting]

ChatGPT is good for finding out about best practice in RSS-based feed readers.

I asked this question:

my reader depends on <guid> for identity. should we not enter those items in the database? obviously we can't handle updates for those items, how would we know which one to update. should we reject items with no guid?

ChatGPT's sage advice

Short answer: No — you should NOT reject RSS items that have no <guid>.
Instead, create a stable synthetic ID for them.

Why you can’t reject items without GUIDs

• RSS 2.0 makes <guid> optional.
• Many real-world feeds omit it.
• Rejecting those items would make your reader silently drop valid posts.

Recommended identity strategy

Use a stable item key, with fallbacks:

1. If <guid> exists:
   Use (feedId, guidValue) as the identity.

2. Else if <link> exists:
   Use (feedId, normalizedLink) as the identity.

   • Normalize: lowercase host, strip trailing slashes, handle http/https if you choose.

3. Else (no guid, no link):
   Use a synthetic hash such as:
   hash(title + pubDate + description)
   This is rare and imperfect, but better than discarding the item.

Handling updates

• Items with a GUID: updates are easy — overwrite based on (feedId, guid).
• Items with only a link: treat (feedId, link) as the stable key and update on repeats.
• Synthetic-hash items: generally treat repeats as new items; reliable updates aren’t possible.

Best practice summary

• Do not reject items with no GUID.
• Store them using the fallback identification rules above.
• Accept that updates will be imperfect for a small number of feeds.

[scripting]

After much consultation with ChatGPT this is the new function that gets a guid from an item.

• We don't accept guids of zero length.
• If we don't have a guid value but do have a link value we use the link as the guid.
• If we have neither a guid or link, we smash together pubDate and title and md5 it.

Here's the code.

function getItemGuid (item) {
	var guid = "";
	function ok (val) {
		if (val !== undefined) {
			if (val != "null") {
				if (val.length > 0) { //11/21/25 by DW
					return (true);
					}
				}
			}
		return (false);
		}
	if (ok (item.guid)) {
		guid = item.guid;
		}
	else {
		if (ok (item.link)) { //11/21/25 by DW
			guid = item.link;
			}
		else {
			if (ok (item.pubDate)) {
				guid = item.pubDate;
				}
			if (ok (item.title)) {
				guid += item.title;
				}
			if (guid.length > 0) {
				guid = md5 (guid);
				}
			}
		}
	guid = maxStringLength (guid, config.maxGuidLength);
	return (guid);
	}