From 88a204dc27c435f3b5faec231a07a96cb011518c Mon Sep 17 00:00:00 2001
From: Federico Bond <federicobond@gmail.com>
Date: Wed, 18 Oct 2023 11:36:30 -0300
Subject: [PATCH] feat: pass flag_metadata from resolution to evaluation
 details (#212)

Signed-off-by: Federico Bond <federicobond@gmail.com>
---
 openfeature/client.py                      |  1 +
 openfeature/flag_evaluation.py             |  5 ++++-
 openfeature/provider/in_memory_provider.py |  6 ++++--
 tests/test_client.py                       | 23 ++++++++++++++++++++++
 tests/test_flag_evaluation.py              |  6 ++++--
 5 files changed, 36 insertions(+), 5 deletions(-)

diff --git a/openfeature/client.py b/openfeature/client.py
index d907185a..8f06edd2 100644
--- a/openfeature/client.py
+++ b/openfeature/client.py
@@ -377,6 +377,7 @@ def _create_provider_evaluation(
             flag_key=flag_key,
             value=resolution.value,
             variant=resolution.variant,
+            flag_metadata=resolution.flag_metadata or {},
             reason=resolution.reason,
             error_code=resolution.error_code,
             error_message=resolution.error_message,
diff --git a/openfeature/flag_evaluation.py b/openfeature/flag_evaluation.py
index b4f62bf6..b3a066d1 100644
--- a/openfeature/flag_evaluation.py
+++ b/openfeature/flag_evaluation.py
@@ -29,6 +29,8 @@ class Reason(StrEnum):
     UNKNOWN = "UNKNOWN"
 
 
+FlagMetadata = typing.Mapping[str, typing.Any]
+
 T = typing.TypeVar("T", covariant=True)
 
 
@@ -37,6 +39,7 @@ class FlagEvaluationDetails(typing.Generic[T]):
     flag_key: str
     value: T
     variant: typing.Optional[str] = None
+    flag_metadata: FlagMetadata = field(default_factory=dict)
     reason: typing.Optional[Reason] = None
     error_code: typing.Optional[ErrorCode] = None
     error_message: typing.Optional[str] = None
@@ -58,4 +61,4 @@ class FlagResolutionDetails(typing.Generic[U]):
     error_message: typing.Optional[str] = None
     reason: typing.Optional[Reason] = None
     variant: typing.Optional[str] = None
-    flag_metadata: typing.Optional[str] = None
+    flag_metadata: FlagMetadata = field(default_factory=dict)
diff --git a/openfeature/provider/in_memory_provider.py b/openfeature/provider/in_memory_provider.py
index d88f6f7e..b8cbc94a 100644
--- a/openfeature/provider/in_memory_provider.py
+++ b/openfeature/provider/in_memory_provider.py
@@ -1,10 +1,10 @@
 import typing
-from dataclasses import dataclass
+from dataclasses import dataclass, field
 
 from openfeature._backports.strenum import StrEnum
 from openfeature.evaluation_context import EvaluationContext
 from openfeature.exception import ErrorCode
-from openfeature.flag_evaluation import FlagResolutionDetails, Reason
+from openfeature.flag_evaluation import FlagMetadata, FlagResolutionDetails, Reason
 from openfeature.hook import Hook
 from openfeature.provider.metadata import Metadata
 from openfeature.provider.provider import AbstractProvider
@@ -29,6 +29,7 @@ class State(StrEnum):
     flag_key: str
     default_variant: str
     variants: typing.Dict[str, T]
+    flag_metadata: FlagMetadata = field(default_factory=dict)
     state: State = State.ENABLED
     context_evaluator: typing.Optional[
         typing.Callable[["InMemoryFlag", EvaluationContext], FlagResolutionDetails[T]]
@@ -46,6 +47,7 @@ def resolve(
             value=self.variants[self.default_variant],
             reason=Reason.STATIC,
             variant=self.default_variant,
+            flag_metadata=self.flag_metadata,
         )
 
 
diff --git a/tests/test_client.py b/tests/test_client.py
index 79e67d8f..ad6def9b 100644
--- a/tests/test_client.py
+++ b/tests/test_client.py
@@ -7,6 +7,7 @@
 from openfeature.exception import ErrorCode, OpenFeatureError
 from openfeature.flag_evaluation import Reason
 from openfeature.hook import Hook
+from openfeature.provider.in_memory_provider import InMemoryFlag, InMemoryProvider
 from openfeature.provider.no_op_provider import NoOpProvider
 
 
@@ -97,6 +98,28 @@ def test_should_raise_exception_when_invalid_flag_type_provided(no_op_provider_c
     assert flag.reason == Reason.ERROR
 
 
+def test_should_pass_flag_metadata_from_resolution_to_evaluation_details():
+    # Given
+    provider = InMemoryProvider(
+        {
+            "Key": InMemoryFlag(
+                "Key",
+                "true",
+                {"true": True, "false": False},
+                flag_metadata={"foo": "bar"},
+            )
+        }
+    )
+    client = OpenFeatureClient("my-client", None, provider)
+
+    # When
+    details = client.get_boolean_details(flag_key="Key", default_value=False)
+
+    # Then
+    assert details is not None
+    assert details.flag_metadata == {"foo": "bar"}
+
+
 def test_should_handle_a_generic_exception_thrown_by_a_provider(no_op_provider_client):
     # Given
     exception_hook = MagicMock(spec=Hook)
diff --git a/tests/test_flag_evaluation.py b/tests/test_flag_evaluation.py
index 67608989..4241ad95 100644
--- a/tests/test_flag_evaluation.py
+++ b/tests/test_flag_evaluation.py
@@ -2,11 +2,12 @@
 from openfeature.flag_evaluation import FlagEvaluationDetails, Reason
 
 
-def test_evaulation_details_reason_should_be_a_string():
+def test_evaluation_details_reason_should_be_a_string():
     # Given
     flag_key = "my-flag"
     flag_value = 100
     variant = "1-hundred"
+    flag_metadata = {}
     reason = Reason.DEFAULT
     error_code = ErrorCode.GENERAL
     error_message = "message"
@@ -16,6 +17,7 @@ def test_evaulation_details_reason_should_be_a_string():
         flag_key,
         flag_value,
         variant,
+        flag_metadata,
         reason,
         error_code,
         error_message,
@@ -30,7 +32,7 @@ def test_evaulation_details_reason_should_be_a_string():
     assert reason == flag_details.reason
 
 
-def test_evaulation_details_reason_should_be_a_string_when_set():
+def test_evaluation_details_reason_should_be_a_string_when_set():
     # Given
     flag_key = "my-flag"
     flag_value = 100