feat: add pydantic-compatible import validation and deprecate old utilities

Author: greysonlalonde

src/crewai/utilities/import_utils.py

@@ -2,29 +2,94 @@
 
 import importlib
 from types import ModuleType
+from typing import Annotated, Any, TypeAlias
 
+from pydantic import AfterValidator, TypeAdapter
+from typing_extensions import deprecated
 
+
+@deprecated(
+    "Not needed when using `crewai.utilities.import_utils.import_and_validate_definition`"
+)
 class OptionalDependencyError(ImportError):
     """Exception raised when an optional dependency is not installed."""
 
 
-def require(name: str, *, purpose: str) -> ModuleType:
-    """Import a module, raising a helpful error if it's not installed.
+@deprecated(
+    "Use `crewai.utilities.import_utils.import_and_validate_definition` instead."
+)
+def require(name: str, *, purpose: str, attr: str | None = None) -> ModuleType | Any:
+    """Import a module, optionally returning a specific attribute.
 
     Args:
         name: The module name to import.
         purpose: Description of what requires this dependency.
+        attr: Optional attribute name to get from the module.
 
     Returns:
-        The imported module.
+        The imported module or the specified attribute.
 
     Raises:
         OptionalDependencyError: If the module is not installed.
+        AttributeError: If the specified attribute doesn't exist.
     """
     try:
-        return importlib.import_module(name)
+        module = importlib.import_module(name)
+        if attr is not None:
+            return getattr(module, attr)
+        return module
     except ImportError as exc:
+        package_name = name.split(".")[0]
         raise OptionalDependencyError(
             f"{purpose} requires the optional dependency '{name}'.\n"
-            f"Install it with: uv add {name}"
+            f"Install it with: uv add {package_name}"
         ) from exc
+    except AttributeError as exc:
+        raise AttributeError(f"Module '{name}' has no attribute '{attr}'") from exc
+
+
+def validate_import_path(v: str) -> Any:
+    """Import and return the class/function from the import path.
+
+    Args:
+        v: Import path string in the format 'module.path.ClassName'.
+
+    Returns:
+        The imported class or function.
+
+    Raises:
+        ValueError: If the import path is malformed or the module cannot be imported.
+    """
+    module_path, _, attr = v.rpartition(".")
+    if not module_path or not attr:
+        raise ValueError(f"import_path '{v}' must be of the form 'module.ClassName'")
+
+    try:
+        mod = importlib.import_module(module_path)
+    except ImportError as exc:
+        parts = module_path.split(".")
+        if not parts:
+            raise ValueError(f"Malformed import path: '{v}'") from exc
+        package = parts[0]
+        raise ValueError(
+            f"Package '{package}' could not be imported. Install it with: uv add {package}"
+        ) from exc
+
+    if not hasattr(mod, attr):
+        raise ValueError(f"Attribute '{attr}' not found in module '{module_path}'")
+    return getattr(mod, attr)
+
+
+ImportedDefinition: TypeAlias = Annotated[Any, AfterValidator(validate_import_path)]
+adapter = TypeAdapter(ImportedDefinition)
+
+
+def import_and_validate_definition(v: str) -> Any:
+    """Pydantic-compatible function to import a class/function from a string path.
+
+    Args:
+        v: Import path string in the format 'module.path.ClassName'.
+    Returns:
+        The imported class or function
+    """
+    return adapter.validate_python(v)

tests/utilities/test_import_utils.py

@@ -1,9 +1,16 @@
 """Tests for import utilities."""
 
+import sys
+from unittest.mock import MagicMock, patch
+
 import pytest
-from unittest.mock import patch
 
-from crewai.utilities.import_utils import require, OptionalDependencyError
+from crewai.utilities.import_utils import (
+    OptionalDependencyError,
+    import_and_validate_definition,
+    require,
+    validate_import_path,
+)
 
 
 class TestRequire:
@@ -40,3 +47,143 @@ def test_require_with_import_error(self):
     def test_optional_dependency_error_is_import_error(self):
         """Test that OptionalDependencyError is a subclass of ImportError."""
         assert issubclass(OptionalDependencyError, ImportError)
+
+    def test_require_with_attr(self):
+        """Test requiring a specific attribute from a module."""
+        loads = require("json", purpose="testing", attr="loads")
+        import json
+
+        assert loads == json.loads
+
+    def test_require_with_nonexistent_attr(self):
+        """Test requiring a nonexistent attribute raises AttributeError."""
+        with pytest.raises(AttributeError) as exc_info:
+            require("json", purpose="testing", attr="nonexistent_attr")
+
+        assert "Module 'json' has no attribute 'nonexistent_attr'" in str(
+            exc_info.value
+        )
+
+    def test_require_extracts_package_name(self):
+        """Test that require correctly extracts package name from module path."""
+        with pytest.raises(OptionalDependencyError) as exc_info:
+            require("some.nested.module.path", purpose="testing")
+
+        error_msg = str(exc_info.value)
+        assert "uv add some" in error_msg
+
+
+class TestValidateImportPath:
+    """Test the validate_import_path function."""
+
+    def test_validate_import_path_success(self):
+        """Test successful import of a class."""
+        result = validate_import_path("json.JSONDecoder")
+        import json
+
+        assert result == json.JSONDecoder
+
+    def test_validate_import_path_malformed_no_module(self):
+        """Test validation with no module path."""
+        with pytest.raises(ValueError) as exc_info:
+            validate_import_path("ClassName")
+
+        assert "import_path 'ClassName' must be of the form 'module.ClassName'" in str(
+            exc_info.value
+        )
+
+    def test_validate_import_path_empty_string(self):
+        """Test validation with empty string."""
+        with pytest.raises(ValueError) as exc_info:
+            validate_import_path("")
+
+        assert "import_path '' must be of the form 'module.ClassName'" in str(
+            exc_info.value
+        )
+
+    def test_validate_import_path_module_not_found(self):
+        """Test validation with non-existent module."""
+        with pytest.raises(ValueError) as exc_info:
+            validate_import_path("nonexistent_module.ClassName")
+
+        error_msg = str(exc_info.value)
+        assert "Package 'nonexistent_module' could not be imported" in error_msg
+        assert "uv add nonexistent_module" in error_msg
+
+    def test_validate_import_path_attribute_not_found(self):
+        """Test validation when attribute doesn't exist in module."""
+        with pytest.raises(ValueError) as exc_info:
+            validate_import_path("json.NonExistentClass")
+
+        assert "Attribute 'NonExistentClass' not found in module 'json'" in str(
+            exc_info.value
+        )
+
+    def test_validate_import_path_nested_module(self):
+        """Test validation with nested module path."""
+        result = validate_import_path("unittest.mock.MagicMock")
+        from unittest.mock import MagicMock
+
+        assert result == MagicMock
+
+    def test_validate_import_path_extracts_package_name(self):
+        """Test that package name is correctly extracted for error message."""
+        with pytest.raises(ValueError) as exc_info:
+            validate_import_path("some.nested.module.path.ClassName")
+
+        error_msg = str(exc_info.value)
+        assert "Package 'some' could not be imported" in error_msg
+        assert "uv add some" in error_msg
+
+
+class TestImportAndValidateDefinition:
+    """Test the import_and_validate_definition function."""
+
+    def test_import_and_validate_definition_success(self):
+        """Test successful import through Pydantic adapter."""
+        result = import_and_validate_definition("json.JSONEncoder")
+        import json
+
+        assert result == json.JSONEncoder
+
+    def test_import_and_validate_definition_with_function(self):
+        """Test importing a function instead of a class."""
+        result = import_and_validate_definition("json.loads")
+        import json
+
+        assert result == json.loads
+
+    def test_import_and_validate_definition_invalid(self):
+        """Test that invalid paths raise ValueError."""
+        with pytest.raises(ValueError) as exc_info:
+            import_and_validate_definition("InvalidPath")
+
+        assert "must be of the form 'module.ClassName'" in str(exc_info.value)
+
+    def test_import_and_validate_definition_module_error(self):
+        """Test error handling for missing modules."""
+        with pytest.raises(ValueError) as exc_info:
+            import_and_validate_definition("missing_package.SomeClass")
+
+        error_msg = str(exc_info.value)
+        assert "Package 'missing_package' could not be imported" in error_msg
+        assert "uv add missing_package" in error_msg
+
+    def test_import_and_validate_definition_attribute_error(self):
+        """Test error handling for missing attributes."""
+        with pytest.raises(ValueError) as exc_info:
+            import_and_validate_definition("json.MissingClass")
+
+        assert "Attribute 'MissingClass' not found in module 'json'" in str(
+            exc_info.value
+        )
+
+    def test_import_and_validate_definition_with_mock(self):
+        """Test that mocked modules work correctly."""
+        mock_module = MagicMock()
+        mock_class = MagicMock()
+        mock_module.MockClass = mock_class
+
+        with patch.dict(sys.modules, {"mocked_module": mock_module}):
+            result = import_and_validate_definition("mocked_module.MockClass")
+            assert result == mock_class