chore: added local client implementation for hooks

Author: jsalaber

devcycle_python_sdk/local_client.py

@@ -8,8 +8,11 @@
 from devcycle_python_sdk.api.local_bucketing import LocalBucketing
 from devcycle_python_sdk.exceptions import VariableTypeMismatchError
 from devcycle_python_sdk.managers.config_manager import EnvironmentConfigManager
+from devcycle_python_sdk.managers.eval_hooks_manager import EvalHooksManager, BeforeHookError, AfterHookError
 from devcycle_python_sdk.managers.event_queue_manager import EventQueueManager
 from devcycle_python_sdk.models.bucketed_config import BucketedConfig
+from devcycle_python_sdk.models.eval_hook import EvalHook
+from devcycle_python_sdk.models.eval_hook_context import HookContext
 from devcycle_python_sdk.models.event import DevCycleEvent, EventType
 from devcycle_python_sdk.models.feature import Feature
 from devcycle_python_sdk.models.platform_data import default_platform_data
@@ -51,6 +54,7 @@ def __init__(self, sdk_key: str, options: DevCycleLocalOptions):
         )
 
         self._openfeature_provider: Optional[DevCycleProvider] = None
+        self.eval_hooks_manager = EvalHooksManager(options.eval_hooks)
 
     def get_sdk_platform(self) -> str:
         return "Local"
@@ -133,18 +137,35 @@ def variable(self, user: DevCycleUser, key: str, default_value: Any) -> Variable
                 )
             return Variable.create_default_variable(key, default_value)
 
+        context = HookContext(key, user, default_value)
+        variable = Variable.create_default_variable(
+                key=key, default_value=default_value
+            )
+
         try:
+            before_hook_error = None
+            try:
+                context = self.eval_hooks_manager.run_before(context)
+            except BeforeHookError as e:
+                before_hook_error = e
             variable = self.local_bucketing.get_variable_for_user_protobuf(
                 user, key, default_value
             )
-            if variable:
-                return variable
+            if before_hook_error is None:
+                self.eval_hooks_manager.run_after(context, variable)
+            else :
+                raise before_hook_error
         except VariableTypeMismatchError:
             logger.debug("DevCycle: Variable type mismatch, returning default value")
+        except BeforeHookError as e:
+            self.eval_hooks_manager.run_error(context, e)
+        except AfterHookError as e:
+            self.eval_hooks_manager.run_error(context, e)
         except Exception as e:
             logger.warning(f"DevCycle: Error retrieving variable for user: {e}")
-
-        return Variable.create_default_variable(key, default_value)
+        finally:
+            self.eval_hooks_manager.run_finally(context, variable)
+        return variable
 
     def _generate_bucketed_config(self, user: DevCycleUser) -> BucketedConfig:
         """
@@ -234,6 +255,12 @@ def close(self) -> None:
         self.config_manager.close()
         self.event_queue_manager.close()
 
+    def add_hook(self, eval_hook: EvalHook) -> None:
+        self.eval_hooks_manager.add_hook(eval_hook)
+
+    def clear_hooks(self) -> None:
+        self.eval_hooks_manager.clear_hooks()
+
 
 def _validate_sdk_key(sdk_key: str) -> None:
     if sdk_key is None or len(sdk_key) == 0:

test/test_local_client.py

@@ -9,6 +9,7 @@
 from devcycle_python_sdk import DevCycleLocalClient, DevCycleLocalOptions
 from devcycle_python_sdk.local_client import _validate_user, _validate_sdk_key
 from devcycle_python_sdk.exceptions import MalformedConfigError
+from devcycle_python_sdk.models.eval_hook import EvalHook
 from devcycle_python_sdk.models.event import DevCycleEvent
 from devcycle_python_sdk.models.feature import Feature
 from devcycle_python_sdk.api.local_bucketing import LocalBucketing
@@ -361,6 +362,66 @@ def test_all_variables_exception(self, _):
         result = self.client.all_variables(user)
         self.assertEqual(result, {})
 
+    def test_hooks(self):
+        self.setup_client()
+        # Test adding hooks
+        hook_called = {"before": False, "after": False, "finally": False, "error": False}
+
+        def before_hook(context):
+            hook_called["before"] = True
+            return context
+
+        def after_hook(context, variable):
+            hook_called["after"] = True
+
+        def finally_hook(context, variable):
+            hook_called["finally"] = True
+
+        def error_hook(context, error):
+            hook_called["error"] = True
+
+        self.client.add_hook(EvalHook(before_hook, after_hook, finally_hook, error_hook))
+
+        # Test hooks called during variable evaluation
+        variable = self.client.variable(self.test_user, "strKey", 42)
+        self.assertTrue(variable.value == 999)
+        self.assertFalse(variable.isDefaulted)
+
+        self.assertTrue(hook_called["before"])
+        self.assertTrue(hook_called["after"])
+        self.assertTrue(hook_called["finally"])
+        self.assertFalse(hook_called["error"])
+
+    def test_hook_exceptions(self):
+        self.setup_client()
+        # Test adding hooks
+        hook_called = {"before": False, "after": False, "finally": False, "error": False}
+
+        def before_hook(context):
+            hook_called["before"] = True
+            raise Exception("Before hook failed")
+
+        def after_hook(context, variable):
+            hook_called["after"] = True
+
+        def finally_hook(context, variable):
+            hook_called["finally"] = True
+
+        def error_hook(context, error):
+            hook_called["error"] = True
+
+        self.client.add_hook(EvalHook(before_hook, after_hook, finally_hook, error_hook))
+
+        # Test hooks called during variable evaluation
+        variable = self.client.variable(self.test_user, "strKey", 42)
+        self.assertTrue(variable.value == 999)
+        self.assertFalse(variable.isDefaulted)
+
+        self.assertTrue(hook_called["before"])
+        self.assertFalse(hook_called["after"])
+        self.assertTrue(hook_called["finally"])
+        self.assertTrue(hook_called["error"])
+
 
 def _benchmark_variable_call(client: DevCycleLocalClient, user: DevCycleUser, key: str):
     return client.variable(user, key, "default_value")