⚡ Optimize demo user setup for performance tests

Use UUID-based demo emails to prevent concurrent profile collisions.\nUse fast PBKDF2 hashing for demo profiles while keeping regular user hashing unchanged.\nAdd focused coverage for hashing, email uniqueness, and the feature flag.\n\nAI-assisted-by: gpt-5.6-luna

backend/src/app/auth.clj

@@ -14,10 +14,19 @@
    :iterations 3
    :parallelism 2})
 
+(def ^:private weak-options
+  {:alg :pbkdf2+sha256
+   :iterations 100})
+
 (defn derive-password
   [password]
   (hashers/derive password default-options))
 
+(defn derive-password-weak
+  "Derives a password with a fast algorithm for demo users."
+  [password]
+  (hashers/derive password weak-options))
+
 (defn verify-password
   [attempt password]
   (try

backend/src/app/rpc/commands/demo.clj

@@ -7,9 +7,10 @@
 (ns app.rpc.commands.demo
   "A demo specific mutations."
   (:require
-   [app.auth :refer [derive-password]]
+   [app.auth :refer [derive-password-weak]]
    [app.common.exceptions :as ex]
    [app.common.time :as ct]
+   [app.common.uuid :as uuid]
    [app.config :as cf]
    [app.db :as db]
    [app.loggers.audit :as audit]
@@ -34,8 +35,8 @@
               :code :demo-users-not-allowed
               :hint "Demo users are disabled by config."))
 
-  (let [sem      (System/currentTimeMillis)
-        email    (str "demo-" sem ".demo@example.com")
+  (let [sem      (uuid/next)
+        email    (str "demo-" sem "@demo.example.com")
         fullname (str "Demo User " sem)
 
         password (-> (bn/random-bytes 16)
@@ -47,7 +48,7 @@
                   :is-active true
                   :is-demo true
                   :deleted-at (ct/in-future (cf/get-deletion-delay))
-                  :password (derive-password password)
+                  :password (derive-password-weak password)
                   :props {}}
         profile  (db/tx-run! cfg (fn [cfg]
                                    (->> (auth/create-profile cfg params)
@@ -55,4 +56,3 @@
     (with-meta {:email email
                 :password password}
       {::audit/profile-id (:id profile)})))
-

backend/test/backend_tests/rpc_demo_test.clj

@@ -0,0 +1,40 @@
+;; This Source Code Form is subject to the terms of the Mozilla Public
+;; License, v. 2.0. If a copy of the MPL was not distributed with this
+;; file, You can obtain one at http://mozilla.org/MPL/2.0/.
+;;
+;; Copyright (c) KALEIDOS INC Sucursal en España SL
+
+(ns backend-tests.rpc-demo-test
+  (:require
+   [app.auth :as auth]
+   [app.config :as cf]
+   [backend-tests.helpers :as th]
+   [clojure.test :as t]))
+
+(t/use-fixtures :once th/state-init)
+(t/use-fixtures :each th/database-reset)
+
+;; Capture the real verifier before the shared test fixture replaces it.
+(def verify-password* auth/verify-password)
+
+(t/deftest weak-password-hash-verifies
+  (let [password "DemoPassword123!"
+        hashed   (auth/derive-password-weak password)]
+    (t/is (:valid (verify-password* password hashed)))))
+
+(t/deftest create-demo-profile-uses-unique-uuid-email
+  (with-redefs [cf/flags (conj cf/flags :demo-users)]
+    (let [first-result  (th/command! {::th/type :create-demo-profile})
+          second-result (th/command! {::th/type :create-demo-profile})
+          first-profile  (:result first-result)
+          second-profile (:result second-result)]
+      (t/is (nil? (:error first-result)))
+      (t/is (nil? (:error second-result)))
+      (t/is (re-matches #"demo-[0-9a-fA-F-]+@demo\.example\.com"
+                        (:email first-profile)))
+      (t/is (not= (:email first-profile) (:email second-profile))))))
+
+(t/deftest create-demo-profile-requires-feature-flag
+  (with-redefs [cf/flags (disj cf/flags :demo-users)]
+    (let [{:keys [error]} (th/command! {::th/type :create-demo-profile})]
+      (t/is (th/ex-of-code? error :demo-users-not-allowed)))))