error handling readOnly input's validity object and validationMessage

[alexmeier-19]

What is affected?

Component

Description

<input id="123" type="number" readOnly></input>

Default step value for this is "1". Now if you set this readOnly input in JS document.getElementById("123").value = "0.5" you'll get following:

input.reportValidity() = true
input.checkValidity() = true

BUT
input.validity Object will have "stepMismatch: true"
and
input.validationMessage = ''.
This seems to be a problem for material-web internal validation logic. It doesn't like a property of the validity object to be 'true' and an empty validationMessage at the same time.

Reproduction

create a number readOnly material web input and set its value to "0.5"

Workaround

Ensure all the inputs would be theoretically valid, although validation shouldn't be triggered in this case.

Is this a regression?

No or unsure. This never worked, or I haven't tried before.

Affected versions

1.5.0

Browser/OS/Node environment

Chrome, Windows