core: Add ruff rules PT (pytest) (#29381)

See https://docs.astral.sh/ruff/rules/#flake8-pytest-style-pt

libs/core/tests/unit_tests/utils/test_aiter.py

@@ -6,7 +6,7 @@ from langchain_core.utils.aiter import abatch_iterate
 
 
 @pytest.mark.parametrize(
-    "input_size, input_iterable, expected_output",
+    ("input_size", "input_iterable", "expected_output"),
     [
         (2, [1, 2, 3, 4, 5], [[1, 2], [3, 4], [5]]),
         (3, [10, 20, 30, 40, 50], [[10, 20, 30], [40, 50]]),

libs/core/tests/unit_tests/utils/test_env.py

@@ -51,7 +51,12 @@ def test_get_from_dict_or_env() -> None:
 
     # Not the most obvious behavior, but
     # this is how it works right now
-    with pytest.raises(ValueError):
+    with pytest.raises(
+        ValueError,
+        match="Did not find not exists, "
+        "please add an environment variable `__SOME_KEY_IN_ENV` which contains it, "
+        "or pass `not exists` as a named parameter.",
+    ):
         assert (
             get_from_dict_or_env(
                 {

libs/core/tests/unit_tests/utils/test_function_calling.py

@@ -37,7 +37,7 @@ from langchain_core.utils.function_calling import (
 )
 
 
-@pytest.fixture()
+@pytest.fixture
 def pydantic() -> type[BaseModel]:
     class dummy_function(BaseModel):  # noqa: N801
         """Dummy function."""
@@ -48,7 +48,7 @@ def pydantic() -> type[BaseModel]:
     return dummy_function
 
 
-@pytest.fixture()
+@pytest.fixture
 def annotated_function() -> Callable:
     def dummy_function(
         arg1: ExtensionsAnnotated[int, "foo"],
@@ -59,7 +59,7 @@ def annotated_function() -> Callable:
     return dummy_function
 
 
-@pytest.fixture()
+@pytest.fixture
 def function() -> Callable:
     def dummy_function(arg1: int, arg2: Literal["bar", "baz"]) -> None:
         """Dummy function.
@@ -72,7 +72,7 @@ def function() -> Callable:
     return dummy_function
 
 
-@pytest.fixture()
+@pytest.fixture
 def function_docstring_annotations() -> Callable:
     def dummy_function(arg1: int, arg2: Literal["bar", "baz"]) -> None:
         """Dummy function.
@@ -85,7 +85,7 @@ def function_docstring_annotations() -> Callable:
     return dummy_function
 
 
-@pytest.fixture()
+@pytest.fixture
 def runnable() -> Runnable:
     class Args(ExtensionsTypedDict):
         arg1: ExtensionsAnnotated[int, "foo"]
@@ -97,7 +97,7 @@ def runnable() -> Runnable:
     return RunnableLambda(dummy_function)
 
 
-@pytest.fixture()
+@pytest.fixture
 def dummy_tool() -> BaseTool:
     class Schema(BaseModel):
         arg1: int = Field(..., description="foo")
@@ -114,7 +114,7 @@ def dummy_tool() -> BaseTool:
     return DummyFunction()
 
 
-@pytest.fixture()
+@pytest.fixture
 def dummy_structured_tool() -> StructuredTool:
     class Schema(BaseModel):
         arg1: int = Field(..., description="foo")
@@ -128,7 +128,7 @@ def dummy_structured_tool() -> StructuredTool:
     )
 
 
-@pytest.fixture()
+@pytest.fixture
 def dummy_structured_tool_args_schema_dict() -> StructuredTool:
     args_schema = {
         "type": "object",
@@ -150,7 +150,7 @@ def dummy_structured_tool_args_schema_dict() -> StructuredTool:
     )
 
 
-@pytest.fixture()
+@pytest.fixture
 def dummy_pydantic() -> type[BaseModel]:
     class dummy_function(BaseModel):  # noqa: N801
         """Dummy function."""
@@ -161,7 +161,7 @@ def dummy_pydantic() -> type[BaseModel]:
     return dummy_function
 
 
-@pytest.fixture()
+@pytest.fixture
 def dummy_pydantic_v2() -> type[BaseModelV2Maybe]:
     class dummy_function(BaseModelV2Maybe):  # noqa: N801
         """Dummy function."""
@@ -174,7 +174,7 @@ def dummy_pydantic_v2() -> type[BaseModelV2Maybe]:
     return dummy_function
 
 
-@pytest.fixture()
+@pytest.fixture
 def dummy_typing_typed_dict() -> type:
     class dummy_function(TypingTypedDict):  # noqa: N801
         """Dummy function."""
@@ -185,7 +185,7 @@ def dummy_typing_typed_dict() -> type:
     return dummy_function
 
 
-@pytest.fixture()
+@pytest.fixture
 def dummy_typing_typed_dict_docstring() -> type:
     class dummy_function(TypingTypedDict):  # noqa: N801
         """Dummy function.
@@ -201,7 +201,7 @@ def dummy_typing_typed_dict_docstring() -> type:
     return dummy_function
 
 
-@pytest.fixture()
+@pytest.fixture
 def dummy_extensions_typed_dict() -> type:
     class dummy_function(ExtensionsTypedDict):  # noqa: N801
         """Dummy function."""
@@ -212,7 +212,7 @@ def dummy_extensions_typed_dict() -> type:
     return dummy_function
 
 
-@pytest.fixture()
+@pytest.fixture
 def dummy_extensions_typed_dict_docstring() -> type:
     class dummy_function(ExtensionsTypedDict):  # noqa: N801
         """Dummy function.
@@ -228,7 +228,7 @@ def dummy_extensions_typed_dict_docstring() -> type:
     return dummy_function
 
 
-@pytest.fixture()
+@pytest.fixture
 def json_schema() -> dict:
     return {
         "title": "dummy_function",
@@ -246,7 +246,7 @@ def json_schema() -> dict:
     }
 
 
-@pytest.fixture()
+@pytest.fixture
 def anthropic_tool() -> dict:
     return {
         "name": "dummy_function",
@@ -266,7 +266,7 @@ def anthropic_tool() -> dict:
     }
 
 
-@pytest.fixture()
+@pytest.fixture
 def bedrock_converse_tool() -> dict:
     return {
         "toolSpec": {

libs/core/tests/unit_tests/utils/test_iter.py

@@ -4,7 +4,7 @@ from langchain_core.utils.iter import batch_iterate
 
 
 @pytest.mark.parametrize(
-    "input_size, input_iterable, expected_output",
+    ("input_size", "input_iterable", "expected_output"),
     [
         (2, [1, 2, 3, 4, 5], [[1, 2], [3, 4], [5]]),
         (3, [10, 20, 30, 40, 50], [[10, 20, 30], [40, 50]]),

libs/core/tests/unit_tests/utils/test_json_schema.py

@@ -147,7 +147,7 @@ def test_dereference_refs_remote_ref() -> None:
             "first_name": {"$ref": "https://somewhere/else/name"},
         },
     }
-    with pytest.raises(ValueError):
+    with pytest.raises(ValueError, match="ref paths are expected to be URI fragments"):
         dereference_refs(schema)
 
 

libs/core/tests/unit_tests/utils/test_rm_titles.py

@@ -220,7 +220,7 @@ output5 = {
 
 
 @pytest.mark.parametrize(
-    "schema, output",
+    ("schema", "output"),
     [
         (schema1, output1),
         (schema2, output2),

libs/core/tests/unit_tests/utils/test_usage.py

@@ -29,12 +29,17 @@ def test_dict_int_op_nested() -> None:
 def test_dict_int_op_max_depth_exceeded() -> None:
     left = {"a": {"b": {"c": 1}}}
     right = {"a": {"b": {"c": 2}}}
-    with pytest.raises(ValueError):
+    with pytest.raises(
+        ValueError, match="max_depth=2 exceeded, unable to combine dicts."
+    ):
         _dict_int_op(left, right, operator.add, max_depth=2)
 
 
 def test_dict_int_op_invalid_types() -> None:
     left = {"a": 1, "b": "string"}
     right = {"a": 2, "b": 3}
-    with pytest.raises(ValueError):
+    with pytest.raises(
+        ValueError,
+        match="Only dict and int values are supported.",
+    ):
         _dict_int_op(left, right, operator.add)

libs/core/tests/unit_tests/utils/test_utils.py

@@ -46,7 +46,7 @@ def test_check_package_version(
 
 @pytest.mark.parametrize(
     ("left", "right", "expected"),
-    (
+    [
         # Merge `None` and `1`.
         ({"a": None}, {"a": 1}, {"a": 1}),
         # Merge `1` and `None`.
@@ -111,7 +111,7 @@ def test_check_package_version(
             {"a": [{"idx": 0, "b": "f"}]},
             {"a": [{"idx": 0, "b": "{"}, {"idx": 0, "b": "f"}]},
         ),
-    ),
+    ],
 )
 def test_merge_dicts(
     left: dict, right: dict, expected: Union[dict, AbstractContextManager]
@@ -130,7 +130,7 @@ def test_merge_dicts(
 
 @pytest.mark.parametrize(
     ("left", "right", "expected"),
-    (
+    [
         # 'type' special key handling
         ({"type": "foo"}, {"type": "foo"}, {"type": "foo"}),
         (
@@ -138,7 +138,7 @@ def test_merge_dicts(
             {"type": "bar"},
             pytest.raises(ValueError, match="Unable to merge."),
         ),
-    ),
+    ],
 )
 @pytest.mark.xfail(reason="Refactors to make in 0.3")
 def test_merge_dicts_0_3(
@@ -183,36 +183,32 @@ def test_guard_import(
 
 
 @pytest.mark.parametrize(
-    ("module_name", "pip_name", "package"),
+    ("module_name", "pip_name", "package", "expected_pip_name"),
     [
-        ("langchain_core.utilsW", None, None),
-        ("langchain_core.utilsW", "langchain-core-2", None),
-        ("langchain_core.utilsW", None, "langchain-coreWX"),
-        ("langchain_core.utilsW", "langchain-core-2", "langchain-coreWX"),
-        ("langchain_coreW", None, None),  # ModuleNotFoundError
+        ("langchain_core.utilsW", None, None, "langchain-core"),
+        ("langchain_core.utilsW", "langchain-core-2", None, "langchain-core-2"),
+        ("langchain_core.utilsW", None, "langchain-coreWX", "langchain-core"),
+        (
+            "langchain_core.utilsW",
+            "langchain-core-2",
+            "langchain-coreWX",
+            "langchain-core-2",
+        ),
+        ("langchain_coreW", None, None, "langchain-coreW"),  # ModuleNotFoundError
     ],
 )
 def test_guard_import_failure(
-    module_name: str, pip_name: Optional[str], package: Optional[str]
+    module_name: str,
+    pip_name: Optional[str],
+    package: Optional[str],
+    expected_pip_name: str,
 ) -> None:
-    with pytest.raises(ImportError) as exc_info:
-        if package is None and pip_name is None:
-            guard_import(module_name)
-        elif package is None and pip_name is not None:
-            guard_import(module_name, pip_name=pip_name)
-        elif package is not None and pip_name is None:
-            guard_import(module_name, package=package)
-        elif package is not None and pip_name is not None:
-            guard_import(module_name, pip_name=pip_name, package=package)
-        else:
-            msg = "Invalid test case"
-            raise ValueError(msg)
-    pip_name = pip_name or module_name.split(".")[0].replace("_", "-")
-    err_msg = (
-        f"Could not import {module_name} python package. "
-        f"Please install it with `pip install {pip_name}`."
-    )
-    assert exc_info.value.msg == err_msg
+    with pytest.raises(
+        ImportError,
+        match=f"Could not import {module_name} python package. "
+        f"Please install it with `pip install {expected_pip_name}`.",
+    ):
+        guard_import(module_name, pip_name=pip_name, package=package)
 
 
 @pytest.mark.skipif(PYDANTIC_MAJOR_VERSION != 2, reason="Requires pydantic 2")