fix types

src/crewai/knowledge/source/base_file_knowledge_source.py

@@ -1,8 +1,8 @@
 from abc import ABC, abstractmethod
 from pathlib import Path
-from typing import Dict, List, Union
+from typing import Dict, List, Optional, Union
 
-from pydantic import Field
+from pydantic import Field, field_validator
 
 from crewai.knowledge.source.base_knowledge_source import BaseKnowledgeSource
 from crewai.knowledge.storage.knowledge_storage import KnowledgeStorage
@@ -14,17 +14,24 @@ class BaseFileKnowledgeSource(BaseKnowledgeSource, ABC):
     """Base class for knowledge sources that load content from files."""
 
     _logger: Logger = Logger(verbose=True)
-    file_path: Union[Path, List[Path], str, List[str]] = Field(
+    file_path: Optional[Union[Path, List[Path], str, List[str]]] = Field(
         default=None,
         description="[Deprecated] The path to the file. Use file_paths instead.",
     )
-    file_paths: Union[Path, List[Path], str, List[str]] = Field(
+    file_paths: Optional[Union[Path, List[Path], str, List[str]]] = Field(
-        ..., description="The path to the file"
+        default_factory=list, description="The path to the file"
     )
     content: Dict[Path, str] = Field(init=False, default_factory=dict)
     storage: KnowledgeStorage = Field(default_factory=KnowledgeStorage)
     safe_file_paths: List[Path] = Field(default_factory=list)
 
+    @field_validator("file_path", "file_paths", mode="before")
+    def validate_file_path(cls, v, values):
+        """Validate that at least one of file_path or file_paths is provided."""
+        if v is None and ("file_path" not in values or values.get("file_path") is None):
+            raise ValueError("Either file_path or file_paths must be provided")
+        return v
+
     def model_post_init(self, _):
         """Post-initialization method to load content."""
         self.safe_file_paths = self._process_file_paths()
@@ -77,6 +84,8 @@ class BaseFileKnowledgeSource(BaseKnowledgeSource, ABC):
                 else self.file_path
             )
         else:
+            if self.file_paths is None:
+                raise ValueError("Your source must be provided with a file_paths: []")
             paths = (
                 [self.file_paths]
                 if isinstance(self.file_paths, (str, Path))