fix(images): backport the image[] and mask[] form key drop to rc/1.102.0 (#39512)

(cherry picked from commit 289c52bcd6)

litellm/proxy/image_endpoints/endpoints.py

@@ -33,6 +33,10 @@ router: Final = APIRouter()
 
 IMAGE_EDIT_NUMERIC_FORM_FIELDS: Final = numeric_form_fields(get_type_hints(ImageEditRequestParams))
 
+IMAGE_ARRAY_FIELD: Final = "image[]"
+MASK_ARRAY_FIELD: Final = "mask[]"
+BRACKETED_FILE_FIELDS: Final = frozenset({IMAGE_ARRAY_FIELD, MASK_ARRAY_FIELD})
+
 
 async def uploadfile_to_bytesio(upload: UploadFile) -> io.BytesIO:
     """
@@ -241,9 +245,9 @@ async def image_edit_api(
     fastapi_response: Response,
     user_api_key_dict: UserAPIKeyAuth = Depends(user_api_key_auth),
     image: list[UploadFile] | None = File(None),
-    image_array: list[UploadFile] | None = File(None, alias="image[]"),
+    image_array: list[UploadFile] | None = File(None, alias=IMAGE_ARRAY_FIELD),
     mask: list[UploadFile] | None = File(None),
-    mask_array: list[UploadFile] | None = File(None, alias="mask[]"),
+    mask_array: list[UploadFile] | None = File(None, alias=MASK_ARRAY_FIELD),
     model: str | None = None,
 ):
     """
@@ -291,12 +295,14 @@ async def image_edit_api(
     #########################################################
     # Read request body and convert UploadFiles to BytesIO
     #########################################################
-    data: Final = dict(
-        coerce_numeric_form_fields(
+    data: Final = {
+        key: value
+        for key, value in coerce_numeric_form_fields(
             parsed_body=await _read_request_body(request=request),
             numeric_fields=IMAGE_EDIT_NUMERIC_FORM_FIELDS,
-        )
-    )
+        ).items()
+        if key not in BRACKETED_FILE_FIELDS
+    }
     image_files: Final = await batch_to_bytesio(image)
     mask_files: Final = await batch_to_bytesio(mask)
     if image_files:

tests/test_litellm/proxy/image_endpoints/test_endpoints.py

@@ -92,18 +92,14 @@ async def test_image_generation_prompt_rerouting(monkeypatch):
     monkeypatch.setattr("litellm.proxy.proxy_server.general_settings", {})
     monkeypatch.setattr("litellm.proxy.proxy_server.llm_router", None)
     monkeypatch.setattr("litellm.proxy.proxy_server.proxy_config", {})
-    monkeypatch.setattr(
-        "litellm.proxy.proxy_server.proxy_logging_obj", fake_proxy_logger
-    )
+    monkeypatch.setattr("litellm.proxy.proxy_server.proxy_logging_obj", fake_proxy_logger)
     monkeypatch.setattr("litellm.proxy.proxy_server.user_model", None)
     monkeypatch.setattr("litellm.proxy.proxy_server.version", "test-version")
     monkeypatch.setattr(
         "litellm.proxy.common_request_processing.ProxyBaseLLMRequestProcessing.get_custom_headers",
         classmethod(lambda *args, **kwargs: {}),
     )
-    monkeypatch.setattr(
-        "litellm.proxy.image_endpoints.endpoints.route_request", fake_route_request
-    )
+    monkeypatch.setattr("litellm.proxy.image_endpoints.endpoints.route_request", fake_route_request)
 
     result = await endpoints.image_generation(
         request=request,
@@ -138,6 +134,60 @@ def _image_edit_client(monkeypatch, captured: Dict[str, Any]) -> TestClient:
     return TestClient(app)
 
 
+def test_image_edit_image_array_alias_is_not_forwarded(monkeypatch):
+    """The documented `image[]` alias must reach the provider only as `image`."""
+    captured: Dict[str, Any] = {}
+
+    response = _image_edit_client(monkeypatch, captured).post(
+        "/v1/images/edits",
+        files={"image[]": ("tree.png", b"\x89PNG\r\n\x1a\ntree", "image/png")},
+        data={"model": "gpt-image-1", "prompt": "add a hat"},
+    )
+
+    assert response.status_code == 200
+    assert "image[]" not in captured
+    assert [buffer.getvalue() for buffer in captured["image"]] == [b"\x89PNG\r\n\x1a\ntree"]
+    assert [buffer.name for buffer in captured["image"]] == ["tree.png"]
+
+
+def test_image_edit_mask_array_alias_is_not_forwarded(monkeypatch):
+    """`mask[]` has the same shape as `image[]` and must be dropped the same way."""
+    captured: Dict[str, Any] = {}
+
+    response = _image_edit_client(monkeypatch, captured).post(
+        "/v1/images/edits",
+        files={
+            "image": ("tree.png", b"\x89PNG\r\n\x1a\ntree", "image/png"),
+            "mask[]": ("mask.png", b"\x89PNG\r\n\x1a\nmask", "image/png"),
+        },
+        data={"model": "gpt-image-1", "prompt": "add a hat"},
+    )
+
+    assert response.status_code == 200
+    assert "mask[]" not in captured
+    assert [buffer.getvalue() for buffer in captured["mask"]] == [b"\x89PNG\r\n\x1a\nmask"]
+    assert [buffer.getvalue() for buffer in captured["image"]] == [b"\x89PNG\r\n\x1a\ntree"]
+
+
+def test_image_edit_canonical_file_fields_still_reach_the_provider(monkeypatch):
+    """Dropping the bracketed aliases must not touch the canonical fields."""
+    captured: Dict[str, Any] = {}
+
+    response = _image_edit_client(monkeypatch, captured).post(
+        "/v1/images/edits",
+        files={
+            "image": ("tree.png", b"\x89PNG\r\n\x1a\ntree", "image/png"),
+            "mask": ("mask.png", b"\x89PNG\r\n\x1a\nmask", "image/png"),
+        },
+        data={"model": "gpt-image-1", "prompt": "add a hat"},
+    )
+
+    assert response.status_code == 200
+    assert [buffer.getvalue() for buffer in captured["image"]] == [b"\x89PNG\r\n\x1a\ntree"]
+    assert [buffer.getvalue() for buffer in captured["mask"]] == [b"\x89PNG\r\n\x1a\nmask"]
+    assert captured["prompt"] == "add a hat"
+
+
 def test_image_edit_multipart_n_reaches_the_provider_as_an_int(monkeypatch):
     """A multipart `n` must not arrive as the string Starlette parsed it into."""
     captured: Dict[str, Any] = {}
@@ -177,7 +227,9 @@ async def test_a_model_the_router_cannot_serve_answers_an_openai_typed_error(mon
     async def fake_add_litellm_data_to_request(**kwargs: object) -> object:
         return kwargs["data"]
 
-    async def fake_pre_call_hook(*, user_api_key_dict: UserAPIKeyAuth, data: dict[str, object], call_type: str) -> dict[str, object]:
+    async def fake_pre_call_hook(
+        *, user_api_key_dict: UserAPIKeyAuth, data: dict[str, object], call_type: str
+    ) -> dict[str, object]:
         return data
 
     async def fake_post_call_failure_hook(**_: object) -> None:
@@ -208,6 +260,8 @@ async def test_a_model_the_router_cannot_serve_answers_an_openai_typed_error(mon
     request = Request({"type": "http", "method": "POST", "path": "/v1/images/generations", "headers": []}, receive)
 
     with pytest.raises(ProxyException) as raised:
-        await endpoints.image_generation(request=request, fastapi_response=Response(), user_api_key_dict=UserAPIKeyAuth())
+        await endpoints.image_generation(
+            request=request, fastapi_response=Response(), user_api_key_dict=UserAPIKeyAuth()
+        )
 
     assert (raised.value.type, raised.value.param, raised.value.code) == ("invalid_request_error", None, "404")