It seems very strange to me that the ARIA alternative to select size=1 has been implemented as a button that opens a list box. select size=1 should be output as a combobox according to the specification. I personally think it would be better: as listbox (https://github.com/w3c/html-aam/issues/230). Be that as it may: a button is wrong. Example: In JAWS all combo boxes and list boxes can be listed with INS+CTRL+C: The button will then not be displayed.
Another problem is that form fields have a label and a value that are output separately. A button has only a label and no value. The example includes the value in the label. However, this leads to an incorrect output by the screen reader.
Regarding https://w3c.github.io/aria-practices/examples/listbox/listbox-collapsible.html
It seems very strange to me that the ARIA alternative to select size=1 has been implemented as a button that opens a list box. select size=1 should be output as a combobox according to the specification. I personally think it would be better: as listbox (https://github.com/w3c/html-aam/issues/230). Be that as it may: a button is wrong. Example: In JAWS all combo boxes and list boxes can be listed with INS+CTRL+C: The button will then not be displayed.
Another problem is that form fields have a label and a value that are output separately. A button has only a label and no value. The example includes the value in the label. However, this leads to an incorrect output by the screen reader.
My suggestion: Remove the example and revise it.
See also: https://github.com/w3c/aria-practices/issues/657