feat(utils): Implement VFSHelper for in-memory artifact management

backend/tests/test_vfs.py

@@ -0,0 +1,49 @@
+import pytest
+from ea_chatbot.utils.vfs import VFSHelper
+
+def test_vfs_read_write():
+    """Verify that we can write and read from the VFS."""
+    vfs = {}
+    helper = VFSHelper(vfs)
+    
+    helper.write("test.txt", "Hello World", metadata={"type": "text"})
+    assert "test.txt" in vfs
+    assert vfs["test.txt"]["content"] == "Hello World"
+    assert vfs["test.txt"]["metadata"]["type"] == "text"
+    
+    content, metadata = helper.read("test.txt")
+    assert content == "Hello World"
+    assert metadata["type"] == "text"
+
+def test_vfs_list():
+    """Verify that we can list files in the VFS."""
+    vfs = {}
+    helper = VFSHelper(vfs)
+    
+    helper.write("a.txt", "content a")
+    helper.write("b.txt", "content b")
+    
+    files = helper.list()
+    assert "a.txt" in files
+    assert "b.txt" in files
+    assert len(files) == 2
+
+def test_vfs_delete():
+    """Verify that we can delete files from the VFS."""
+    vfs = {}
+    helper = VFSHelper(vfs)
+    
+    helper.write("test.txt", "Hello")
+    helper.delete("test.txt")
+    
+    assert "test.txt" not in vfs
+    assert len(helper.list()) == 0
+
+def test_vfs_not_found():
+    """Verify that reading a non-existent file returns None."""
+    vfs = {}
+    helper = VFSHelper(vfs)
+    
+    content, metadata = helper.read("missing.txt")
+    assert content is None
+    assert metadata is None