feat: add FeatureProvider protocol (#268)

Signed-off-by: Federico Bond <federicobond@gmail.com>

openfeature/api.py

@@ -4,11 +4,11 @@
 from openfeature.evaluation_context import EvaluationContext
 from openfeature.exception import GeneralError
 from openfeature.hook import Hook
+from openfeature.provider import FeatureProvider
 from openfeature.provider.metadata import Metadata
 from openfeature.provider.no_op_provider import NoOpProvider
-from openfeature.provider.provider import AbstractProvider
 
-_provider: AbstractProvider = NoOpProvider()
+_provider: FeatureProvider = NoOpProvider()
 
 _evaluation_context = EvaluationContext()
 
@@ -21,7 +21,7 @@ def get_client(
     return OpenFeatureClient(name=name, version=version, provider=_provider)
 
 
-def set_provider(provider: AbstractProvider) -> None:
+def set_provider(provider: FeatureProvider) -> None:
     global _provider
     if provider is None:
         raise GeneralError(error_message="No provider")
@@ -31,7 +31,7 @@ def set_provider(provider: AbstractProvider) -> None:
     provider.initialize(_evaluation_context)
 
 
-def get_provider() -> typing.Optional[AbstractProvider]:
+def get_provider() -> typing.Optional[FeatureProvider]:
     global _provider
     return _provider
 

openfeature/client.py

@@ -24,8 +24,8 @@
     before_hooks,
     error_hooks,
 )
+from openfeature.provider import FeatureProvider
 from openfeature.provider.no_op_provider import NoOpProvider
-from openfeature.provider.provider import AbstractProvider
 
 logger = logging.getLogger("openfeature")
 
@@ -69,7 +69,7 @@ def __init__(
         self,
         name: typing.Optional[str],
         version: typing.Optional[str],
-        provider: AbstractProvider,
+        provider: FeatureProvider,
         context: typing.Optional[EvaluationContext] = None,
         hooks: typing.Optional[typing.List[Hook]] = None,
     ) -> None:

openfeature/provider/__init__.py

@@ -0,0 +1,61 @@
+import typing
+
+from openfeature.evaluation_context import EvaluationContext
+from openfeature.flag_evaluation import FlagResolutionDetails
+from openfeature.hook import Hook
+
+from .metadata import Metadata
+
+
+class FeatureProvider(typing.Protocol):  # pragma: no cover
+    def initialize(self, evaluation_context: EvaluationContext) -> None:
+        ...
+
+    def shutdown(self) -> None:
+        ...
+
+    def get_metadata(self) -> Metadata:
+        ...
+
+    def get_provider_hooks(self) -> typing.List[Hook]:
+        ...
+
+    def resolve_boolean_details(
+        self,
+        flag_key: str,
+        default_value: bool,
+        evaluation_context: typing.Optional[EvaluationContext] = None,
+    ) -> FlagResolutionDetails[bool]:
+        ...
+
+    def resolve_string_details(
+        self,
+        flag_key: str,
+        default_value: str,
+        evaluation_context: typing.Optional[EvaluationContext] = None,
+    ) -> FlagResolutionDetails[str]:
+        ...
+
+    def resolve_integer_details(
+        self,
+        flag_key: str,
+        default_value: int,
+        evaluation_context: typing.Optional[EvaluationContext] = None,
+    ) -> FlagResolutionDetails[int]:
+        ...
+
+    def resolve_float_details(
+        self,
+        flag_key: str,
+        default_value: float,
+        evaluation_context: typing.Optional[EvaluationContext] = None,
+    ) -> FlagResolutionDetails[float]:
+        ...
+
+    def resolve_object_details(
+        self,
+        flag_key: str,
+        default_value: typing.Union[dict, list],
+        evaluation_context: typing.Optional[EvaluationContext] = None,
+    ) -> FlagResolutionDetails[typing.Union[dict, list]]:
+        ...

openfeature/provider/provider.py

@@ -4,10 +4,11 @@
 from openfeature.evaluation_context import EvaluationContext
 from openfeature.flag_evaluation import FlagResolutionDetails
 from openfeature.hook import Hook
+from openfeature.provider import FeatureProvider
 from openfeature.provider.metadata import Metadata
 
 
-class AbstractProvider:
+class AbstractProvider(FeatureProvider):
     def initialize(self, evaluation_context: EvaluationContext) -> None:
         pass
 

tests/test_api.py

@@ -19,7 +19,7 @@
 from openfeature.hook import Hook
 from openfeature.provider.metadata import Metadata
 from openfeature.provider.no_op_provider import NoOpProvider
-from openfeature.provider.provider import AbstractProvider
+from openfeature.provider.provider import FeatureProvider
 
 
 def test_should_not_raise_exception_with_noop_client():
@@ -61,7 +61,7 @@ def test_should_try_set_provider_and_fail_if_none_provided():
 def test_should_invoke_provider_initialize_function_on_newly_registered_provider():
     # Given
     evaluation_context = EvaluationContext("targeting_key", {"attr1": "val1"})
-    provider = MagicMock(spec=AbstractProvider)
+    provider = MagicMock(spec=FeatureProvider)
 
     # When
     set_evaluation_context(evaluation_context)
@@ -73,8 +73,8 @@ def test_should_invoke_provider_initialize_function_on_newly_registered_provider
 
 def test_should_invoke_provider_shutdown_function_once_provider_is_no_longer_in_use():
     # Given
-    provider_1 = MagicMock(spec=AbstractProvider)
-    provider_2 = MagicMock(spec=AbstractProvider)
+    provider_1 = MagicMock(spec=FeatureProvider)
+    provider_2 = MagicMock(spec=FeatureProvider)
 
     # When
     set_provider(provider_1)
@@ -148,7 +148,7 @@ def test_should_add_hooks_to_api_hooks():
 
 def test_should_call_provider_shutdown_on_api_shutdown():
     # Given
-    provider = MagicMock(spec=AbstractProvider)
+    provider = MagicMock(spec=FeatureProvider)
     set_provider(provider)
 
     # When