feat: add tests for context merging

Author: lukas-reining

openfeature/api.py

@@ -36,7 +36,9 @@
 ]
 
 _evaluation_context = EvaluationContext()
-_evaluation_transaction_context_propagator = NoOpTransactionContextPropagator()
+_evaluation_transaction_context_propagator: TransactionContextPropagator = (
+    NoOpTransactionContextPropagator()
+)
 
 _hooks: typing.List[Hook] = []
 

openfeature/transaction_context/context_var_transaction_context_propagator.py

@@ -5,14 +5,14 @@
     TransactionContextPropagator,
 )
 
-_transaction_context_var: ContextVar[EvaluationContext] = ContextVar(
-    "transaction_context", default=EvaluationContext()
-)
-
 
 class ContextVarsTransactionContextPropagator(TransactionContextPropagator):
+    _transaction_context_var: ContextVar[EvaluationContext] = ContextVar(
+        "transaction_context", default=EvaluationContext()
+    )
+
     def get_transaction_context(self) -> EvaluationContext:
-        return _transaction_context_var.get()
+        return self._transaction_context_var.get()
 
     def set_transaction_context(self, transaction_context: EvaluationContext) -> None:
-        _transaction_context_var.set(transaction_context)
+        self._transaction_context_var.set(transaction_context)

tests/test_client.py

@@ -1,19 +1,22 @@
 import time
 import uuid
 from concurrent.futures import ThreadPoolExecutor
-from unittest.mock import MagicMock
+from unittest.mock import MagicMock, Mock
 
 import pytest
 
+from openfeature import api
 from openfeature.api import add_hooks, clear_hooks, get_client, set_provider
 from openfeature.client import OpenFeatureClient
+from openfeature.evaluation_context import EvaluationContext
 from openfeature.event import EventDetails, ProviderEvent, ProviderEventDetails
 from openfeature.exception import ErrorCode, OpenFeatureError
 from openfeature.flag_evaluation import FlagResolutionDetails, Reason
 from openfeature.hook import Hook
 from openfeature.provider import FeatureProvider, ProviderStatus
 from openfeature.provider.in_memory_provider import InMemoryFlag, InMemoryProvider
 from openfeature.provider.no_op_provider import NoOpProvider
+from openfeature.transaction_context import ContextVarsTransactionContextPropagator
 
 
 @pytest.mark.parametrize(
@@ -384,3 +387,47 @@ def emit_events_task():
         f2 = executor.submit(emit_events_task)
         f1.result()
         f2.result()
+
+
+def test_client_should_merge_contexts():
+    api.clear_hooks()
+    api.set_transaction_context_propagator(ContextVarsTransactionContextPropagator())
+
+    provider = NoOpProvider()
+    provider.resolve_boolean_details = MagicMock(wraps=provider.resolve_boolean_details)
+    api.set_provider(provider)
+
+    # Global evaluation context
+    global_context = EvaluationContext(
+        targeting_key="global", attributes={"global_attr": "global_value"}
+    )
+    api.set_evaluation_context(global_context)
+
+    # Transaction context
+    transaction_context = EvaluationContext(
+        targeting_key="transaction",
+        attributes={"transaction_attr": "transaction_value"},
+    )
+    api.set_transaction_context(transaction_context)
+
+    # Client-specific context
+    client_context = EvaluationContext(
+        targeting_key="client", attributes={"client_attr": "client_value"}
+    )
+    client = OpenFeatureClient(domain=None, version=None, context=client_context)
+
+    # Invocation-specific context
+    invocation_context = EvaluationContext(
+        targeting_key="invocation", attributes={"invocation_attr": "invocation_value"}
+    )
+    client.get_boolean_details("flag", False, invocation_context)
+
+    # Retrieve the call arguments
+    args, kwargs = provider.resolve_boolean_details.call_args
+    flag_key, default_value, context = args
+
+    assert context.targeting_key == "invocation"  # Last one in the merge chain
+    assert context.attributes["global_attr"] == "global_value"
+    assert context.attributes["transaction_attr"] == "transaction_value"
+    assert context.attributes["client_attr"] == "client_value"
+    assert context.attributes["invocation_attr"] == "invocation_value"

tests/test_transaction_context.py

@@ -15,9 +15,6 @@
     NoOpTransactionContextPropagator,
     TransactionContextPropagator,
 )
-from openfeature.transaction_context.context_var_transaction_context_propagator import (
-    _transaction_context_var,
-)
 
 
 # Test cases
@@ -97,8 +94,12 @@ def test_should_propagate_event_when_context_set():
     set_transaction_context(evaluation_context)
 
     # Then
-    assert _transaction_context_var.get().targeting_key == "custom_key"
-    assert _transaction_context_var.get().attributes == {"attr1": "val1"}
+    assert (
+        custom_propagator._transaction_context_var.get().targeting_key == "custom_key"
+    )
+    assert custom_propagator._transaction_context_var.get().attributes == {
+        "attr1": "val1"
+    }
 
 
 def test_context_vars_transaction_context_propagator_multiple_threads():