Fix Agent unintentionally modifying stream for all Prompt Drivers (…

…#1442)

CHANGELOG.md

@@ -7,10 +7,6 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## Unreleased
 
-## Fixed
-
-- Exception when calling `Structure.to_json()` after it has run.
-
 ### Added
 
 - `PromptTask.conversation_memory` for setting the Conversation Memory on a Prompt Task.
@@ -19,6 +15,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - `BranchTask` for selecting which Tasks (if any) to run based on a condition.
 - Support for `BranchTask` in `StructureVisualizer`.
 
+### Fixed
+
+- Exception when calling `Structure.to_json()` after it has run.
+- `Agent` unintentionally modifying `stream` for all Prompt Drivers.
+
 ## [1.0.0] - 2024-12-09
 
 ### Added

griptape/structures/agent.py

@@ -2,7 +2,7 @@
 
 from typing import TYPE_CHECKING, Callable, Optional, Union
 
-from attrs import Attribute, Factory, define, field
+from attrs import Attribute, Factory, define, evolve, field
 
 from griptape.artifacts.text_artifact import TextArtifact
 from griptape.common import observable
@@ -24,7 +24,10 @@ class Agent(Structure):
     )
     stream: bool = field(default=Factory(lambda: Defaults.drivers_config.prompt_driver.stream), kw_only=True)
     prompt_driver: BasePromptDriver = field(
-        default=Factory(lambda: Defaults.drivers_config.prompt_driver), kw_only=True
+        default=Factory(
+            lambda self: evolve(Defaults.drivers_config.prompt_driver, stream=self.stream), takes_self=True
+        ),
+        kw_only=True,
     )
     tools: list[BaseTool] = field(factory=list, kw_only=True)
     max_meta_memory_entries: Optional[int] = field(default=20, kw_only=True)

tests/unit/structures/test_agent.py

@@ -276,3 +276,11 @@ def test_is_running(self):
         task.state = BaseTask.State.RUNNING
 
         assert agent.is_running()
+
+    def test_stream_mutation(self):
+        prompt_driver = MockPromptDriver()
+        agent = Agent(prompt_driver=MockPromptDriver(), stream=True)
+
+        assert isinstance(agent.tasks[0], PromptTask)
+        assert agent.tasks[0].prompt_driver.stream is True
+        assert agent.tasks[0].prompt_driver is not prompt_driver