In my else block, the second line does not appear to be running. It runs setHelperText but seems to ignore setAlertValue.
const [alertValue, setAlertValue] = useState("error");
const [errValue, setErrorValue] = useState("Error State");
const [helperText, setHelperText] = useState('Input "success" to remove error');
const handleChange = (e) => {
setErrorValue(e.target.value);
if (e.target.value === "success") {
setAlertValue(null);
setHelperText("Update input to re-enable error");
} else
setHelperText('Input "success" to remove error');
setAlertValue("error"); // this line does not run
};
<TextField
label="Error State"
message="this is an ERROR message"
alert={alertValue}
value={errValue}
onChange={handleChange}
helperText={helperText}
/>
Curly braces are missing in your code. It should be like this:
if (e.target.value === "success") {
setAlertValue(null);
setHelperText("Update input to re-enable error");
} else {
setHelperText('Input "success" to remove error');
setAlertValue("error");
};