Files
ragflow/test
nickmopen 5b02fe4841 fix(api): stop duplicating answer in openai-compatible chat completions stream (#15286) (#15443)
### What problem does this PR solve?

Fixes #15286.

When calling `/api/v1/openai/<chat_id>/chat/completions` with `"stream":
true`, the response contains the answer **twice** — the final message
repeats everything that was already streamed.

#### Root cause

RAGFlow's `async_chat` streams the body as incremental `delta.content`
chunks, then emits a terminating `final` event whose `answer` is the
**complete** (decorated) message. The handler re-emitted that full
answer as one more `delta.content` chunk:

```python
if ans.get("final"):
    if ans.get("answer"):
        full_content = ans["answer"]
        response["choices"][0]["delta"]["content"] = full_content   # <-- whole answer again
        yield ...
```

So a client accumulating `delta.content` ends up with the message
duplicated.

#### Fix

Drop the re-emission. The complete answer from the `final` event is now
surfaced **only** through the trailing chunk's `final_content` and
`reference` fields, which matches OpenAI streaming semantics: deltas are
incremental, and the final chunk carries only `finish_reason` / `usage`
(plus RAGFlow's `reference` / `final_content` extensions).

This matches the expected behavior described in the issue: "The stream
should only yield content chunks once, and the final message should only
contain reference, usage, and finish_reason."

#### Testability refactor

The streaming SSE assembly was a closure inside the request handler, so
it could only be exercised against a live server + real LLM. I extracted
it into a module-level `_stream_chat_completion_sse` async generator
(behavior-preserving) so it can be unit-tested with a fake event stream.

#### Tests

Adds
`test/unit_test/api/apps/restful_apis/test_openai_stream_no_duplicate.py`
(same import-stub pattern as the existing `test_get_agent_session.py`):

- body is streamed exactly once (the regression);
- the complete answer is never re-emitted as a content chunk;
- the terminating chunk has `finish_reason="stop"`, `content=None`, and
correct `usage`;
- `final_content` / `reference` are present on the trailing chunk;
- reasoning (`think`) deltas stream separately and are not duplicated.

> Note: this is unrelated to #15442, which only changes the `stream`
default — it does not touch the duplication logic.

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)
- [x] Added test cases

---------

Co-authored-by: Wang Qi <wangq8@outlook.com>
2026-06-02 13:20:40 +08:00
..


(1). Deploy RAGFlow services and images

https://ragflow.io/docs/build_docker_image

(2). Configure the required environment for testing

Install Python dependencies (including test dependencies):

uv sync --python 3.13 --only-group test --no-default-groups --frozen

Activate the environment:

source .venv/bin/activate

Install SDK:

uv pip install sdk/python 

Modify the .env file: Add the following code:

COMPOSE_PROFILES=${COMPOSE_PROFILES},tei-cpu
TEI_MODEL=BAAI/bge-small-en-v1.5
RAGFLOW_IMAGE=infiniflow/ragflow:v0.25.6 #Replace with the image you are using

Start the containerwait two minutes:

docker compose -f docker/docker-compose.yml up -d


(3). Test Elasticsearch

a) Run sdk tests against Elasticsearch:

export HTTP_API_TEST_LEVEL=p2
export HOST_ADDRESS=http://127.0.0.1:9380  # Ensure that this port is the API port mapped to your localhost
pytest -s --tb=short --level=${HTTP_API_TEST_LEVEL} test/testcases/test_sdk_api 

b) Run http api tests against Elasticsearch:

pytest -s --tb=short --level=${HTTP_API_TEST_LEVEL} test/testcases/test_http_api 


(4). Test Infinity

Modify the .env file:

DOC_ENGINE=${DOC_ENGINE:-infinity}

Start the container:

docker compose -f docker/docker-compose.yml down -v 
docker compose -f docker/docker-compose.yml up -d

a) Run sdk tests against Infinity:

DOC_ENGINE=infinity pytest -s --tb=short --level=${HTTP_API_TEST_LEVEL} test/testcases/test_sdk_api 

b) Run http api tests against Infinity:

DOC_ENGINE=infinity pytest -s --tb=short --level=${HTTP_API_TEST_LEVEL} test/testcases/test_http_api