Added liking and security measures

features/people/REGISTER_people.js

@@ -62,6 +62,17 @@ async function create_people(req, res) {
     const person = req.person;
     let db_id;
 
+    const existing = await pool
+        .query('SELECT 1 FROM people WHERE username = $1 OR email = $2 LIMIT 1', [
+            person.username,
+            person.email,
+        ])
+        .catch(() => null);
+    if (existing && existing.rowCount > 0) {
+        res.status(409).send('Username or email is already in use');
+        return;
+    }
+
     try {
         db_id = await insert_db(
             person.name,
@@ -71,6 +82,10 @@ async function create_people(req, res) {
         );
     }
     catch (err) {
+        if (err.code === '23505') {
+            res.status(409).send('Username or email is already in use');
+            return;
+        }
         res.status(500).send('Data was not pushed to database, request failed');
         return;
     }
@@ -80,6 +95,9 @@ async function create_people(req, res) {
         res.status(201).json({ id: db_id });
     }
     catch (err) {
+        // Compensate the SQL insert so the user does not exist in one database
+        // but not the other.
+        await pool.query('DELETE FROM people WHERE id = $1', [db_id]).catch(() => {});
         res.status(500).send('Data was not pushed to graph database, request failed');
     }
 };