Execute SQLs for email_signups in transaction

plume-models/src/email_signups.rs

@@ -90,15 +90,18 @@ impl EmailSignup {
     }
 
     pub fn confirm(&self, conn: &DbConn) -> Result<()> {
+        conn.transaction(|| {
             Self::ensure_user_not_exist_by_email(conn, &self.email)?;
             if self.expired() {
                 Self::delete_existings_by_email(conn, &self.email)?;
                 return Err(Error::Expired);
             }
             Ok(())
+        })
     }
 
     pub fn complete(&self, conn: &DbConn, username: String, password: String) -> Result<User> {
+        conn.transaction(|| {
             Self::ensure_user_not_exist_by_email(conn, &self.email)?;
             let user = NewUser::new_local(
                 conn,
@@ -111,6 +114,7 @@ impl EmailSignup {
             )?;
             self.delete(conn)?;
             Ok(user)
+        })
     }
 
     fn delete(&self, conn: &DbConn) -> Result<()> {