feat: add redis fallback mechanism #21043 (#21044)

Co-authored-by: tech <cto@sb>
Co-authored-by: crazywoola <100913391+crazywoola@users.noreply.github.com>
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

api/tests/unit_tests/extensions/test_redis.py

@@ -0,0 +1,53 @@
+from redis import RedisError
+
+from extensions.ext_redis import redis_fallback
+
+
+def test_redis_fallback_success():
+    @redis_fallback(default_return=None)
+    def test_func():
+        return "success"
+
+    assert test_func() == "success"
+
+
+def test_redis_fallback_error():
+    @redis_fallback(default_return="fallback")
+    def test_func():
+        raise RedisError("Redis error")
+
+    assert test_func() == "fallback"
+
+
+def test_redis_fallback_none_default():
+    @redis_fallback()
+    def test_func():
+        raise RedisError("Redis error")
+
+    assert test_func() is None
+
+
+def test_redis_fallback_with_args():
+    @redis_fallback(default_return=0)
+    def test_func(x, y):
+        raise RedisError("Redis error")
+
+    assert test_func(1, 2) == 0
+
+
+def test_redis_fallback_with_kwargs():
+    @redis_fallback(default_return={})
+    def test_func(x=None, y=None):
+        raise RedisError("Redis error")
+
+    assert test_func(x=1, y=2) == {}
+
+
+def test_redis_fallback_preserves_function_metadata():
+    @redis_fallback(default_return=None)
+    def test_func():
+        """Test function docstring"""
+        pass
+
+    assert test_func.__name__ == "test_func"
+    assert test_func.__doc__ == "Test function docstring"