fix: support legacy metadata (#777)

* fix: support legacy metadata

* Update unit coverage badge

---------

Co-authored-by: leoguillaume <leoguillaume@users.noreply.github.com>

Author: leoguillaume

.github/badges/coverage.json

@@ -1 +1 @@
-{"schemaVersion":1,"label":"coverage","message":"51.01%","color":"red"}
+{"schemaVersion":1,"label":"coverage","message":"50.18%","color":"red"}

api/schemas/chunks.py

@@ -1,7 +1,7 @@
 from datetime import datetime
 from typing import Annotated, Literal
 
-from pydantic import Field, StringConstraints, field_serializer, model_validator
+from pydantic import Field, StringConstraints, field_serializer, field_validator, model_validator
 
 from api.schemas import BaseModel
 
@@ -43,6 +43,25 @@ class Chunk(BaseModel):
     metadata: Annotated[ChunkMetadata | None, Field(default=None, description="Metadata of the chunk")]
     created: Annotated[datetime, Field(default=datetime.now(), description="The date of the chunk creation.")]
 
+    @field_validator("metadata", mode="before")
+    @classmethod
+    def support_legacy_metadata(cls, metadata: dict | None) -> dict | None:
+        if metadata is None:
+            return None
+
+        normalized_metadata = {}
+        for key, value in metadata.items():
+            if value is None:
+                continue
+            if isinstance(value, list):
+                normalized_value = ",".join(str(item).strip() for item in value if str(item).strip())
+                if normalized_value:
+                    normalized_metadata[key] = normalized_value
+                continue
+            normalized_metadata[key] = value
+
+        return normalized_metadata
+
     @field_serializer("created")
     def serialize_created(self, created: datetime) -> int:
         return int(created.timestamp())

api/tests/unit/test_legacy.py

@@ -0,0 +1,20 @@
+from datetime import datetime
+
+from api.schemas.chunks import Chunk
+
+
+def test_pydantic_chunck_model_support_legacy_metadata():
+    """Test that the Chunk model supports legacy metadata, None type and list. None are ignored, list are converted to a string by joining the strings with a comma."""
+    # Given
+    content = {
+        "id": 1,
+        "collection_id": 1,
+        "document_id": 1,
+        "content": "test",
+        "created": datetime.now(),
+        "metadata": {"list_metadata": ["tag1", "tag2"], "none_metadata": None},
+    }
+    # When
+    result = Chunk(**content)
+    # Then
+    assert result.metadata == {"list_metadata": "tag1,tag2"}