Setting readOnly AND computed on properties

[positlabs]

Obviously, we can't set a value on a computed property, but setting readOnly: true causes the computed property handler to never be called. Maybe there should be some warning, or even an error if a property is configured like this. Or possibly just ignore the readOnly flag if computed is defined.

                _optionLabels: {
                    type: Array,
                    value: [],
                    readOnly: true,
                    computed: '_computedOptionLabels(options)'
                },

[kevinpschaaf]

This is a bug.

The expected behavior is that making a property computed should implicitly make it readOnly, since it should never be set from outside, only as a result of the computing function running based on dependencies changing.

Currently it is neither readOnly by default, nor does attempting to make it readOnly manually work, as noted.

[positlabs]

Nice. Thanks for fixing!