Custom block SelectControl works but equivalent ComboboxControl gives errors – where’s my mistake?

This took me a while to figure out… It’s a bug. The JavaScript error occurs because the onFilterValueChange function is not defined… Even though the WordPress documentation says this function is optional. Simply adding onFilterValueChange with an anonymous function removes the JavaScript error.

E.g.

<ComboboxControl
    label="Font Size"
    value="small"
    options={[
        {
            value: "small",
            label: "Small"
        },
        {
            value: "normal",
            label: "Normal"
        },
        {
            value: "large",
            label: "Large"
        },
        {
            value: "huge",
            label: "Huge"
        }
    ]}
    onInputChange={(inputValue) =>
        setFilteredOptions(
            [
                {
                    value: "small",
                    label: "Small"
                },
                {
                    value: "normal",
                    label: "Normal"
                },
                {
                    value: "large",
                    label: "Large"
                },
                {
                    value: "huge",
                    label: "Huge"
                }
            ].filter(option =>
                option.label.toLowerCase().startsWith(inputValue.toLowerCase())
            )
        )
    }
    onFilterValueChange={() => {}}
/>