Experimental widget drop-down shows "Duplicate" even when the field storage setting is set to 1

Nice catch. Let's try to get some failing tests here then. :)
Let's go to dev. :)

Also just stumbled across this.

We fixed something similar for the remove button.
5b5532c #2919186: Hide "Remove" button if cardinality 1 (required) and only one allowed Paragraph type

Working on this. :)

This should work. :)

+++ b/src/Plugin/Field/FieldWidget/ParagraphsWidget.php
@@ -2491,4 +2491,32 @@ class ParagraphsWidget extends WidgetBase {
+
+    // Hide the button if field cardinality is one.
+    if ($cardinality == 1) {
+      return FALSE;
+    }

A more generic way of putting this would be to say that duplicate should follow a similar rule as adding a new paragraph. It should not be allowed if there is a fixed cardinality. So e.g. if you have cardinality 2 and 2 paragraphs you shoudln't see it but you should if you only have one.

But I think that's very hard to check inside the item loop, when you have to consider deleted paragraphs and so on.

So I think this is fine, a fixed cardinality > 1 is a pretty rare use case I think.

Yeah, let's cover the basic case here. Committed and thanks! :-)

Yes, we recently simplified to always show the table even when it is single value. Drag and drop changes are possible but likely then configurable.

#7

A more generic way of putting this would be to say that duplicate should follow a similar rule as adding a new paragraph. It should not be allowed if there is a fixed cardinality. So e.g. if you have cardinality 2 and 2 paragraphs you shoudln't see it but you should if you only have one.

I created a follow-up to fix this issue: #3115916: Do not show 'Duplicate' action when maximum items has been reached for fields with cardinality > 1