langchain[patch]: Fix how the serializable test identifies serializable objects (#21165)

dir() will not work if we're using optional imports. The only way to do this is by using contents of __all__

libs/langchain/tests/unit_tests/load/test_serializable.py

@@ -1,5 +1,7 @@
 import importlib
+import inspect
 import pkgutil
+from types import ModuleType
 
 from langchain_core.load.mapping import SERIALIZABLE_MAPPING
 
@@ -8,37 +10,71 @@ def import_all_modules(package_name: str) -> dict:
     package = importlib.import_module(package_name)
     classes: dict = {}
 
-    for attribute_name in dir(package):
-        attribute = getattr(package, attribute_name)
-        if hasattr(attribute, "is_lc_serializable") and isinstance(attribute, type):
+    def _handle_module(module: ModuleType) -> None:
+        # Iterate over all members of the module
+
+        names = dir(module)
+
+        if hasattr(module, "__all__"):
+            names += list(module.__all__)
+
+        names = sorted(set(names))
+
+        for name in names:
+            # Check if it's a class or function
+            attr = getattr(module, name)
+
+            if not inspect.isclass(attr):
+                continue
+
+            if not hasattr(attr, "is_lc_serializable") or not isinstance(attr, type):
+                continue
+
             if (
-                isinstance(attribute.is_lc_serializable(), bool)  # type: ignore
-                and attribute.is_lc_serializable()  # type: ignore
+                isinstance(attr.is_lc_serializable(), bool)  # type: ignore
+                and attr.is_lc_serializable()  # type: ignore
             ):
-                key = tuple(attribute.lc_id())  # type: ignore
-                value = tuple(attribute.__module__.split(".") + [attribute.__name__])
+                key = tuple(attr.lc_id())  # type: ignore
+                value = tuple(attr.__module__.split(".") + [attr.__name__])
                 if key in classes and classes[key] != value:
                     raise ValueError
                 classes[key] = value
-    if hasattr(package, "__path__"):
-        for loader, module_name, is_pkg in pkgutil.walk_packages(
-            package.__path__, package_name + "."
-        ):
-            if module_name not in (
-                "langchain.chains.llm_bash",
-                "langchain.chains.llm_symbolic_math",
-                "langchain_community.tools.python",
-                "langchain_community.vectorstores._pgvector_data_models",
-            ):
-                importlib.import_module(module_name)
-                new_classes = import_all_modules(module_name)
-                for k, v in new_classes.items():
-                    if k in classes and classes[k] != v:
-                        raise ValueError
-                    classes[k] = v
+
+    _handle_module(package)
+
+    for importer, modname, ispkg in pkgutil.walk_packages(
+        package.__path__, package.__name__ + "."
+    ):
+        try:
+            module = importlib.import_module(modname)
+        except ModuleNotFoundError:
+            continue
+        _handle_module(module)
+
     return classes
 
 
+def test_import_all_modules() -> None:
+    """Test import all modules works as expected"""
+    all_modules = import_all_modules("langchain")
+    filtered_modules = [
+        k
+        for k in all_modules
+        if len(k) == 4 and tuple(k[:2]) == ("langchain", "chat_models")
+    ]
+    # This test will need to be updated if new serializable classes are added
+    # to community
+    assert filtered_modules == [
+        ("langchain", "chat_models", "azure_openai", "AzureChatOpenAI"),
+        ("langchain", "chat_models", "bedrock", "BedrockChat"),
+        ("langchain", "chat_models", "anthropic", "ChatAnthropic"),
+        ("langchain", "chat_models", "fireworks", "ChatFireworks"),
+        ("langchain", "chat_models", "google_palm", "ChatGooglePalm"),
+        ("langchain", "chat_models", "openai", "ChatOpenAI"),
+        ("langchain", "chat_models", "vertexai", "ChatVertexAI"),
+    ]
+
+
 def test_serializable_mapping() -> None:
     to_skip = {
         # This should have had a different namespace, as it was never
@@ -59,6 +95,7 @@ def test_serializable_mapping() -> None:
         ),
     }
     serializable_modules = import_all_modules("langchain")
+
     missing = set(SERIALIZABLE_MAPPING).difference(
         set(serializable_modules).union(to_skip)
     )