Use Promise instead of async/await in ExternalAccount

lib/models/external-account.js

@@ -68,40 +68,41 @@ class ExternalAccount {
    * @returns {Promise<ExternalAccount>}
    * @memberof ExternalAccount
    */
-  static async findOrRegister(providerType, accountId, usernameToBeRegistered) {
-
-    const account = await this.findOne({ providerType, accountId })
-    // found
-    if (account != null) {
-      debug(`ExternalAccount '${accountId}' is found `, account);
-      return account;
-    }
-
-    const User = ExternalAccount.crowi.model('User');
-    const Config = ExternalAccount.crowi.model('Config');
-
-    const treatExternalUserAsLocalUser = Config.shouldTreatExternalAccountAsLocal(ExternalAccount.crowi.getConfig());
-
-    const users = await User.find({username: usernameToBeRegistered})
-
-    // throw Exception when count is not zero
-    const maxDuplicateUserCount = treatExternalUserAsLocalUser ? 1 : 0;
-    if (users.length > maxDuplicateUserCount) {
-      throw new DuplicatedUsernameException(`username '${usernameToBeRegistered}' has already been existed`);
-    }
-
-    let newUser;
-    if (users.length === 0) {
-      debug(`ExternalAccount '${accountId}' is not found, it is going to be registered.`);
-      // create user with STATUS_ACTIVE
-      newUser = await User.createUser('', usernameToBeRegistered, undefined, undefined, undefined, User.STATUS_ACTIVE);
-    }
-    else {
-      debug(`ExternalAccount '${accountId}' will be linked to an exisiting account`);
-      newUser = users[0];
-    }
+  static findOrRegister(providerType, accountId, usernameToBeRegistered) {
+
+    return this.findOne({ providerType, accountId }).then( account => {
+      // found
+      if (account != null) {
+        debug(`ExternalAccount '${accountId}' is found `, account);
+        return account;
+      }
+
+      const User = ExternalAccount.crowi.model('User');
+      const Config = ExternalAccount.crowi.model('Config');
+
+      const treatExternalUserAsLocalUser = Config.shouldTreatExternalAccountAsLocal(ExternalAccount.crowi.getConfig());
+
+      return User.find({username: usernameToBeRegistered}).then( users => {
+        // throw Exception when count is not zero
+        const maxDuplicateUserCount = treatExternalUserAsLocalUser ? 1 : 0;
+        if (users.length > maxDuplicateUserCount) {
+          throw new DuplicatedUsernameException(`username '${usernameToBeRegistered}' has already been existed`);
+        }
+
+        if (users.length === 0) {
+          debug(`ExternalAccount '${accountId}' is not found, it is going to be registered.`);
+          // create user with STATUS_ACTIVE
+          return User.createUser('', usernameToBeRegistered, undefined, undefined, undefined, User.STATUS_ACTIVE);
+        }
+
+        debug(`ExternalAccount '${accountId}' will be linked to an exisiting account`);
+        return users[0];
+
+      }).then( newUser => {
+        return this.create({ providerType: 'ldap', accountId, user: newUser._id });
+      })
 
-    return this.create({ providerType: 'ldap', accountId, user: newUser._id });
+    });
   }
 
   /**