add group creation

src/server/db.ts

@@ -80,25 +80,25 @@ class DB {
      * @param mail: string
      * @returns created user
      */
-    public async createUser(mail: string): Promise<User> {
-        const user: User = await this.instance`
+    public async createUser(mail: string): Promise<User | null> {
+        const user: User[] = await this.instance`
             INSERT INTO users (mail) VALUES (${mail})
             RETURNING *    
         `;
 
-        return user;
+        return user[0] ?? null;
     }
 
     /**
      * Get user by mail
      * @param mail: string
-     * @returns user object or undefined
+     * @returns user object or null
      */
-    public async getUserByMail(mail: string): Promise<User | undefined> {
-        const user: User = await this.instance`
+    public async getUserByMail(mail: string): Promise<User | null> {
+        const user: User[] = await this.instance`
             SELECT * FROM users WHERE mail = ${mail}
         `;
-        return user;
+        return user[0] ?? null;
     }
 
     /* GROUPS */
@@ -109,25 +109,26 @@ class DB {
      * @param mail: string
      * @returns object with id of the created group
      */
-    public async createGroup( {name, mail}: {name: string, mail: string}): Promise<Group> {
+    public async createGroup( {name, mail}: {name: string, mail: string}): Promise<Group | null> {
         const code = Math.random().toString(36).substring(2, 8).toUpperCase();
-        const group: Group = await this.instance`
+        const group: Group[] = await this.instance`
             INSERT INTO groups (code, name, mail) VALUES (${code}, ${name}, ${mail})
             RETURNING *
         `;
-        return group;
+        console.log('Created group:', group);
+        return group[0] ?? null;
     };
 
     /**
      * Get group by ID
      * @param id: string
-     * @returns group object or undefined
+     * @returns group object or null
      */
-    public async getGroupByCode(code: string): Promise<Group | undefined> {
-        const group: Group | undefined = await this.instance`
+    public async getGroupByCode(code: string): Promise<Group | null> {
+        const group: Group[] = await this.instance`
             SELECT * FROM groups WHERE code = ${code}
         `;
-        return group;
+        return group[0] ?? null;
     }
 
     /* GROUP MEMBER */