firstName: yup
.string()
.test(
'len',
'can be empty or with string at least 2 characters and not more than 10',
(val) => val != undefined && (val.length == 0 || (val.length >= 2 && val.length <= 10) )
)
in this case length min 2 and max 10 works, but when is empty is marked with error i tried with val.length == 0
fixed by separate undefined check
firstName: yup
.string()
.test(
'len',
'can be empty or with string at least 2 characters and not more than 10',
(val) => {
if (val == undefined) {
return true;
}
return ((val.length == 0 || (val.length >= 2 && val.length <= 10)))
}
),
Hello you can do it like this
const yup = require("yup");
const firstName = "";
const schema = yup
.string()
.test(
"len",
"can be empty or with string at least 2 characters and not more than 10",
(val) => {
if (val === undefined) {
return true;
}
return val.length === 0 || (val.length >= 2 && val.length <= 10);
}
);
schema
.validate(firstName)
.then((response) => console.log(response))
.catch((err) => console.log(err));