Accept str or list[str] for shell (#4060)

Relax the requirements

langchain/tools/shell/tool.py

@@ -1,7 +1,7 @@
 import asyncio
 import platform
 import warnings
-from typing import List, Optional, Type
+from typing import List, Optional, Type, Union
 
 from pydantic import BaseModel, Field, root_validator
 
@@ -16,7 +16,7 @@ from langchain.utilities.bash import BashProcess
 class ShellInput(BaseModel):
     """Commands for the Bash Shell tool."""
 
-    commands: List[str] = Field(
+    commands: Union[str, List[str]] = Field(
         ...,
         description="List of shell commands to run. Deserialized using json.loads",
     )
@@ -66,7 +66,7 @@ class ShellTool(BaseTool):
 
     def _run(
         self,
-        commands: List[str],
+        commands: Union[str, List[str]],
         run_manager: Optional[CallbackManagerForToolRun] = None,
     ) -> str:
         """Run commands and return final output."""
@@ -74,7 +74,7 @@ class ShellTool(BaseTool):
 
     async def _arun(
         self,
-        commands: List[str],
+        commands: Union[str, List[str]],
         run_manager: Optional[AsyncCallbackManagerForToolRun] = None,
     ) -> str:
         """Run commands asynchronously and return final output."""

tests/unit_tests/tools/shell/test_shell.py

@@ -30,6 +30,12 @@ def test_shell_tool_init() -> None:
     assert shell_tool.process is not None
 
 
+def test_shell_tool_run() -> None:
+    shell_tool = ShellTool()
+    result = shell_tool._run(commands=test_commands)
+    assert result.strip() == "Hello, World!\nAnother command"
+
+
 @pytest.mark.asyncio
 async def test_shell_tool_arun() -> None:
     shell_tool = ShellTool()
@@ -37,7 +43,7 @@ async def test_shell_tool_arun() -> None:
     assert result.strip() == "Hello, World!\nAnother command"
 
 
-def test_shell_tool_run() -> None:
+def test_shell_tool_run_str() -> None:
     shell_tool = ShellTool()
-    result = shell_tool._run(commands=test_commands)
-    assert result.strip() == "Hello, World!\nAnother command"
+    result = shell_tool._run(commands="echo 'Hello, World!'")
+    assert result.strip() == "Hello, World!"