auth0 - invalid user_metadata type - reactjs

Question

I am using Auth0 for user management and I am trying to add some default user_metadata on signup. My signup code looks like this:
// signs a user up
signup(email, password, callback, metadata){
const defaultVals = {
app_complete: false,
app_decision: 'unknown',
app_term: this.getAppTerm(),
nickname: '',
middle_initial: '',
current_age: '10',
}
const meta = Object.assign({}, defaultVals, metadata);
console.log(meta);
this.auth0.redirect.signupAndLogin({
connection: 'Username-Password-Authentication',
email,
password,
user_metadata: meta,
}, function(err, authResult) {
if (err != undefined) {
callback(err);
console.log(err);
return;
}
});}
The problem is, whenever I try to pass the user_metadata attribute app_complete: false, the API returns an error saying that the data type false is invalid, and that only strings are allowed. Error message: invalid user_metadata.app_complete type (only strings are allowed).
I know JSON allows for types other than strings, because I can change this to false through the Auth0 user dashboard. Why is the signup method for the auth0 WebAuth object returning this error?
Thanks.

Answer 1

This is because for signup in the user_metadata you can provide only strings as values.
The user metadata to be associated with the user. If set, the field must be an object containing no more than ten properties. Property names can have a maximum of 100 characters, and property values must be strings of no more than 500 characters.
PATCH on the other hand supports full JSON types in user_metadata.
Here is the reference in the github auth0-js issue

Answer 2

You can pass the user_metadata in the signupAndLogin() (/dbconnections/signup endpoint) method. However, it has some restriction as described below.
The user metadata to be associated with the user. If set, the field
must be an object containing no more than ten properties. Property
names can have a maximum of 100 characters, and property values must
be strings of no more than 500 characters.
To solve the issue, pass the property value as string.
Alternatively, instead of passing the user_metadata in the request, It is possible to use auth0 rules and update the user_metadata on the first login.
function (user, context, callback) {
var count = context.stats && context.stats.loginsCount ? context.stats.loginsCount : 0;
if (count > 1) {
return callback(null, user, context);
}
//update metadata
// https://auth0.com/docs/rules/guides/metadata#update-user_metadata
callback(null, user, context);
}