feat(orchestrator): Harden VFS and enhance artifact awareness across workers

backend/tests/test_vfs_robustness.py

@@ -0,0 +1,48 @@
+import pytest
+import threading
+from ea_chatbot.utils.vfs import safe_vfs_copy
+
+def test_safe_vfs_copy_success():
+    """Test standard success case."""
+    vfs = {
+        "test.csv": {"content": "data", "metadata": {"type": "csv"}},
+        "num": 42
+    }
+    copied = safe_vfs_copy(vfs)
+    assert copied == vfs
+    assert copied is not vfs
+    assert copied["test.csv"] is not vfs["test.csv"]
+
+def test_safe_vfs_copy_handles_non_copyable():
+    """Test replacing uncopyable objects with error placeholders."""
+    # A threading.Lock is famously uncopyable
+    lock = threading.Lock()
+    
+    vfs = {
+        "safe_file": "important data",
+        "unsafe_lock": lock
+    }
+    
+    copied = safe_vfs_copy(vfs)
+    
+    # Safe one remains
+    assert copied["safe_file"] == "important data"
+    
+    # Unsafe one is REPLACED with an error dict
+    assert isinstance(copied["unsafe_lock"], dict)
+    assert "content" in copied["unsafe_lock"]
+    assert "ERROR" in copied["unsafe_lock"]["content"]
+    assert copied["unsafe_lock"]["metadata"]["type"] == "error"
+    assert "lock" in str(copied["unsafe_lock"]["metadata"]["error"]).lower()
+    
+    # Original is unchanged (it was a lock)
+    assert vfs["unsafe_lock"] is lock
+
+def test_safe_vfs_copy_preserves_nested_copyable():
+    """Test deepcopy still works for complex but copyable objects."""
+    vfs = {
+        "data": {"a": [1, 2, 3], "b": {"c": True}}
+    }
+    copied = safe_vfs_copy(vfs)
+    assert copied["data"]["a"] == [1, 2, 3]
+    assert copied["data"]["a"] is not vfs["data"]["a"]