fix(tools): return ErrorArtifact instead of raising StopIteration for unsupported file types

griptape/tools/file_manager/tool.py

@@ -75,7 +75,10 @@ def load_files_from_disk(self, params: dict) -> ListArtifact | ErrorArtifact:
             # Fetch the file to try and determine the appropriate loader
             abs_path = os.path.join(self.file_manager_driver.workdir, path)
             mime_type = get_mime_type(abs_path)
-            loader = next((loader for key, loader in self.loaders.items() if mime_type.startswith(key)))
+            loader = next((loader for key, loader in self.loaders.items() if mime_type.startswith(key)), None)
+
+            if loader is None:
+                return ErrorArtifact(f"Failed to load file '{path}': no loader available for MIME type '{mime_type}'")
 
             artifact = loader.load(path)
             if isinstance(artifact, ListArtifact):

tests/unit/tools/test_file_manager.py

@@ -5,7 +5,7 @@
 
 import pytest
 
-from griptape.artifacts import ListArtifact, TextArtifact
+from griptape.artifacts import ErrorArtifact, ListArtifact, TextArtifact
 from griptape.drivers.file_manager.local_file_manager_driver import LocalFileManagerDriver
 from griptape.tools import FileManagerTool
 from tests.utils import defaults
@@ -44,6 +44,16 @@ def test_load_files_from_disk_with_encoding(self, file_manager):
         assert len(result.value) == 1
         assert isinstance(result.value[0], TextArtifact)
 
+    def test_load_files_from_disk_with_unsupported_file_type(self, temp_dir):
+        with open(os.path.join(temp_dir, "config.json"), "w") as f:
+            f.write('{"a": 1}')
+
+        file_manager = FileManagerTool(file_manager_driver=LocalFileManagerDriver(workdir=temp_dir))
+        result = file_manager.load_files_from_disk({"values": {"paths": ["config.json"]}})
+
+        assert isinstance(result, ErrorArtifact)
+        assert "no loader available" in result.value
+
     def test_save_memory_artifacts_to_disk_for_one_artifact(self, temp_dir):
         memory = defaults.text_task_memory("Memory1")
         artifact = TextArtifact("foobar")