standard-tests[patch]: Add pytest assert rewrites (#24408)

This will surface nice error messages in subclasses that fail assertions.

libs/standard-tests/langchain_standard_tests/integration_tests/__init__.py

@@ -1,3 +1,21 @@
+# ruff: noqa: E402
+import pytest
+
+# Rewrite assert statements for test suite so that implementations can
+# see the full error message from failed asserts.
+# https://docs.pytest.org/en/7.1.x/how-to/writing_plugins.html#assertion-rewriting
+modules = [
+    "base_store",
+    "cache",
+    "chat_models",
+    "vectorstores",
+]
+
+for module in modules:
+    pytest.register_assert_rewrite(
+        f"langchain_standard_tests.integration_tests.{module}"
+    )
+
 from langchain_standard_tests.integration_tests.chat_models import (
     ChatModelIntegrationTests,
 )

libs/standard-tests/langchain_standard_tests/integration_tests/vectorstores.py

@@ -1,4 +1,5 @@
 """Test suite to test vectostores."""
+
 import inspect
 from abc import ABC, abstractmethod
 

libs/standard-tests/langchain_standard_tests/unit_tests/__init__.py

@@ -1,3 +1,16 @@
+# ruff: noqa: E402
+import pytest
+
+# Rewrite assert statements for test suite so that implementations can
+# see the full error message from failed asserts.
+# https://docs.pytest.org/en/7.1.x/how-to/writing_plugins.html#assertion-rewriting
+modules = [
+    "chat_models",
+]
+
+for module in modules:
+    pytest.register_assert_rewrite(f"langchain_standard_tests.unit_tests.{module}")
+
 from langchain_standard_tests.unit_tests.chat_models import ChatModelUnitTests
 
 __all__ = ["ChatModelUnitTests"]

libs/standard-tests/tests/unit_tests/test_in_memory_base_store.py

@@ -1,4 +1,5 @@
 """Tests for the InMemoryStore class."""
+
 from typing import Tuple
 
 import pytest