Allow client to be set in test env

temporalio/activity.py

@@ -148,7 +148,7 @@ class _Context:
         temporalio.converter.PayloadConverter,
     ]
     runtime_metric_meter: Optional[temporalio.common.MetricMeter]
-    client: Client
+    client: Optional[Client]
     _logger_details: Optional[Mapping[str, Any]] = None
     _payload_converter: Optional[temporalio.converter.PayloadConverter] = None
     _metric_meter: Optional[temporalio.common.MetricMeter] = None
@@ -249,7 +249,12 @@ def client() -> Client:
     Raises:
         RuntimeError: When not in an activity.
     """
-    return _Context.current().client
+    client = _Context.current().client
+    if not client:
+        raise RuntimeError(
+            "No client available. In tests you can pass a client when creating ActivityEnvironment."
+        )
+    return client
 
 
 def in_activity() -> bool:

temporalio/testing/_activity.py

@@ -16,6 +16,7 @@
 import temporalio.converter
 import temporalio.exceptions
 import temporalio.worker._activity
+from temporalio.client import Client
 
 _Params = ParamSpec("_Params")
 _Return = TypeVar("_Return")
@@ -62,7 +63,7 @@ class ActivityEnvironment:
             take effect. Default is noop.
     """
 
-    def __init__(self) -> None:
+    def __init__(self, client: Optional[Client] = None) -> None:
         """Create an ActivityEnvironment for running activity code."""
         self.info = _default_info
         self.on_heartbeat: Callable[..., None] = lambda *args: None
@@ -73,6 +74,7 @@ def __init__(self) -> None:
         self._cancelled = False
         self._worker_shutdown = False
         self._activities: Set[_Activity] = set()
+        self._client = client
 
     def cancel(self) -> None:
         """Cancel the activity.
@@ -113,14 +115,15 @@ def run(
             The callable's result.
         """
         # Create an activity and run it
-        return _Activity(self, fn).run(*args, **kwargs)
+        return _Activity(self, fn, self._client).run(*args, **kwargs)
 
 
 class _Activity:
     def __init__(
         self,
         env: ActivityEnvironment,
         fn: Callable,
+        client: Optional[Client],
     ) -> None:
         self.env = env
         self.fn = fn
@@ -148,11 +151,14 @@ def __init__(
                 thread_event=threading.Event(),
                 async_event=asyncio.Event() if self.is_async else None,
             ),
-            shield_thread_cancel_exception=None
-            if not self.cancel_thread_raiser
-            else self.cancel_thread_raiser.shielded,
+            shield_thread_cancel_exception=(
+                None
+                if not self.cancel_thread_raiser
+                else self.cancel_thread_raiser.shielded
+            ),
             payload_converter_class_or_instance=env.payload_converter,
             runtime_metric_meter=env.metric_meter,
+            client=client,
         )
         self.task: Optional[asyncio.Task] = None
 

tests/testing/test_activity.py

@@ -2,8 +2,12 @@
 import threading
 import time
 from contextvars import copy_context
+from unittest.mock import Mock
+
+import pytest
 
 from temporalio import activity
+from temporalio.client import Client
 from temporalio.exceptions import CancelledError
 from temporalio.testing import ActivityEnvironment
 
@@ -110,3 +114,30 @@ async def assert_equals(a: str, b: str) -> None:
 
     assert type(expected_err) == type(actual_err)
     assert str(expected_err) == str(actual_err)
+
+
+async def test_activity_env_without_client():
+    saw_error: bool = False
+
+    def my_activity() -> None:
+        with pytest.raises(RuntimeError):
+            activity.client()
+        nonlocal saw_error
+        saw_error = True
+
+    env = ActivityEnvironment()
+    env.run(my_activity)
+    assert saw_error
+
+
+async def test_activity_env_with_client():
+    got_client: bool = False
+
+    def my_activity() -> None:
+        nonlocal got_client
+        if activity.client():
+            got_client = True
+
+    env = ActivityEnvironment(client=Mock(spec=Client))
+    env.run(my_activity)
+    assert got_client