feat(auth0-js): correct dbconnection signup details (#41847)

- property name (`userMetadata`)
- missing props
- props documentation
- typed signup callback results options

https://git.io/Jvqte

Thanks!

types/auth0-js/auth0-js-tests.ts

@@ -150,7 +150,7 @@ webAuth.signupAndAuthorize({
     password: '123456',
     scope: 'openid',
     username: "blabla",
-    user_metadata: {
+    userMetadata: {
         foo: 'bar'
     }
 }, (err, data) => {});
@@ -263,9 +263,40 @@ authentication.getUserCountry((err, data) => {});
 authentication.getSSOData();
 authentication.getSSOData(true, (err, data) => {});
 
+// $ExpectError
+authentication.dbConnection.signup();
+// $ExpectError
+authentication.dbConnection.signup({});
+// $ExpectError
+authentication.dbConnection.signup({ connection: 'bla', email: 'blabla' });
+// $ExpectError
+authentication.dbConnection.signup({ connection: 'bla', email: 'blabla', password: '123456' });
 authentication.dbConnection.signup(
     { connection: 'bla', email: 'blabla', password: '123456', username: 'blabla' },
-    () => {}
+    (auth0Error, results) => {
+        if (auth0Error) {
+            const { error, errorDescription } = auth0Error;
+        }
+        if (results) {
+            const { email, emailVerified } = results;
+        }
+    },
+);
+authentication.dbConnection.signup(
+    {
+        email: 'the email',
+        password: 'the password',
+        connection: 'the_connection',
+        userMetadata: {
+            firstName: 'Toon',
+            lastName: 'De Coninck',
+            last_location: 'Mexico',
+        },
+    },
+    (err, data) => {
+        console.assert(err === null);
+        console.assert(data.email !== null);
+    },
 );
 authentication.dbConnection.changePassword({connection: 'bla', email: 'blabla'}, () => {});
 

types/auth0-js/index.d.ts

@@ -113,11 +113,10 @@ export class DBConnection {
     constructor(request: any, option: any);
 
     /**
-     * Signup a new user
-     *
-     * @param options: https://auth0.com/docs/api/authentication#!#post--dbconnections-signup
+     * Creates a new user in a Auth0 Database connection
+     * @param options https://auth0.com/docs/api/authentication#signup
      */
-    signup(options: DbSignUpOptions, callback: Auth0Callback<any>): void;
+    signup(options: DbSignUpOptions, callback: Auth0Callback<DbSignUpResults>): void;
 
     /**
      * Initializes the change password flow
@@ -834,13 +833,25 @@ export interface DelegationOptions {
 }
 
 export interface DbSignUpOptions {
+    /** user email address */
     email: string;
+    /** user password */
     password: string;
+    /** name of the connection where the user will be created */
     connection: string;
     /** User desired username. Required if you use a database connection and you have enabled `Requires Username` */
     username?: string;
     scope?: string;
-    user_metadata?: any;
+    /** additional signup attributes used for creating the user. Will be stored in `user_metadata` */
+    userMetadata?: any;
+}
+
+/** result of the signup request */
+export interface DbSignUpResults {
+    /** user's email */
+    email: string;
+    /** if the user's email was verified */
+    emailVerified: boolean;
 }
 
 export interface ParseHashOptions {