failed WRONG_FIX wrong_fix · 18 tool calls · 120 s · fastapi/fastapi
♻️ Validate Server Sent Event fields to avoid applications from sending broken data ## Pull Request <!-- Please start with a GitHub Discussion. Once a team member asks you to open a PR, create it and link the discussion here. Obvious typo fixes can be made in a PR without starting a discussion. --> Discussion: <!-- Link to the GitHub Discussion --> ## Description ♻️ Validate Server Sent Event fields to avoid applications from sending broken data This was reported multiple times as a "vulnerability" by users probably using automated AI tools, with the argument that if input was taken from the request and passed directly to an event unfiltered, it could break the client. If an app sets an `id` or `event` with multi-line content, I would consider that app broken, and probably the app itself vulnerable to something, not FastAPI. With this change, if any app sets invalid multi-line values (sourced from unfiltered input or in any other way), FastAPI will make it a server error (which it is, as the app is sending invalid data). I don't think the code before this PR has a bug, less a vulnerability. This change is mainly a quality of life improvement to prevent badly written apps from shooting themselves in the foot by passing unsanitized data directly to a SSE. <!-- Write the description of your PR here --> ## AI Disclaimer <!-- If using AI, write here the prompt and model used --> Codex with GPT-5.5 <details> <summary>AI transcript</summary> <!-- Paste here the entire AI transcript --> </details> ## Checklist - [ ] This PR is an obvious typo fix, or it links to a GitHub Discussion for the proposed code change. - [x] I added tests for the change. - [x] The new or updated tests fail on the main branch and pass on this PR. - [x] Coverage stays at 100%. - [x] The documentation explains the change if needed.
| # | Tool | Arguments | Result |
|---|---|---|---|
| 1 | run_command | {
"command": "grep -rn \"EventSourceResponse\" . | head -20"
} | {"status": "ok", "stdout": "./fastapi/.agents/skills/fastapi/references/streaming.md:16:To stream Server-Sent Events, use `response_class=EventSourceResponse` afull{"status": "ok", "stdout": "./fastapi/.agents/skills/fastapi/references/streaming.md:16:To stream Server-Sent Events, use `response_class=EventSourceResponse` and `yield` items from the endpoint.\n./fastapi/.agents/skills/fastapi/references/streaming.md:24:from fastapi.sse import EventSourceResponse\n./fastapi/.agents/skills/fastapi/references/streaming.md:35:@app.get(\"/items/stream\", response_class=EventSourceResponse)\n./fastapi/.agents/skills/fastapi/references/streaming.md:47:from fastapi.sse import EventSourceResponse, ServerSentEvent\n./fastapi/.agents/skills/fastapi/references/streaming.md:52:@app.get(\"/events\", response_class=EventSourceResponse)\n./fastapi/.agents/skills/fastapi/SKILL.md:333:See [the streaming reference](references/streaming.md) for JSON Lines, Server-Sent Events (`EventSourceResponse`, `ServerSentEvent`), and byte streaming (`StreamingResponse`) patterns.\n./fastapi/routing.py:64: EventSourceResponse,\n./fastapi/routing.py:376: is_sse_stream = lenient_issubclass(actual_response_class, EventSourceResponse)\n./fastapi/routing.py:856: # EventSourceResponse (SSE).\n./fastapi/routing.py:862: or lenient_issubclass(response_class, EventSourceResponse)\n./fastapi/routing.py:971: response_class, EventSourceResponse\n./fastapi/responses.py:5:from fastapi.sse import EventSourceResponse as EventSourceResponse # noqa\n./fastapi/sse.py:20:class EventSourceResponse(StreamingResponse):\n./fastapi/sse.py:23: Use as `response_class=EventSourceResponse` on a *path operation* that uses `yield`\n./fastapi/sse.py:46: `response_class=EventSourceResponse`, each `ServerSentEvent` is encoded\n./tests/test_sse.py:8:from fastapi.responses import EventSourceResponse\n./tests/test_sse.py:29:@app.get(\"/items/stream\", response_class=EventSourceResponse)\n./tests/test_sse.py:35:@app.get(\"/items/stream-sync\", response_class=EventSourceResponse)\n./tests/test_sse.py:40:@app.get(\"/items/stream-no-anno |
| 2 | read_file | {
"filepath": "fastapi/sse.py"
} | {"status": "ok", "filepath": "fastapi/sse.py", "content": "from typing import Annotated, Any\n\nfrom annotated_doc import Doc\nfrom pydantic import AfterValidatfull{"status": "ok", "filepath": "fastapi/sse.py", "content": "from typing import Annotated, Any\n\nfrom annotated_doc import Doc\nfrom pydantic import AfterValidator, BaseModel, Field, model_validator\nfrom starlette.responses import StreamingResponse\n\n# Canonical SSE event schema matching the OpenAPI 3.2 spec\n# (Section 4.14.4 \"Special Considerations for Server-Sent Events\")\n_SSE_EVENT_SCHEMA: dict[str, Any] = {\n \"type\": \"object\",\n \"properties\": {\n \"data\": {\"type\": \"string\"},\n \"event\": {\"type\": \"string\"},\n \"id\": {\"type\": \"string\"},\n \"retry\": {\"type\": \"integer\", \"minimum\": 0},\n },\n}\n\n\nclass EventSourceResponse(StreamingResponse):\n \"\"\"Streaming response with `text/event-stream` media type.\n\n Use as `response_class=EventSourceResponse` on a *path operation* that uses `yield`\n to enable Server Sent Events (SSE) responses.\n\n Works with **any HTTP method** (`GET`, `POST`, etc.), which makes it compatible\n with protocols like MCP that stream SSE over `POST`.\n\n The actual encoding logic lives in the FastAPI routing layer. This class\n serves mainly as a marker and sets the correct `Content-Type`.\n \"\"\"\n\n media_type = \"text/event-stream\"\n\n\ndef _check_id_no_null(v: str | None) -> str | None:\n if v is not None and \"\\0\" in v:\n raise ValueError(\"SSE 'id' must not contain null characters\")\n return v\n\n\nclass ServerSentEvent(BaseModel):\n \"\"\"Represents a single Server-Sent Event.\n\n When `yield`ed from a *path operation function* that uses\n `response_class=EventSourceResponse`, each `ServerSentEvent` is encoded\n into the [SSE wire format](https://html.spec.whatwg.org/multipage/server-sent-events.html#parsing-an-event-stream)\n (`text/event-stream`).\n\n If you yield a plain object (dict, Pydantic model, etc.) instead, it is\n automatically JSON-encoded and sent as the `data:` field.\n\n All `data` |
| 3-4 ×2 | read_file | {
"filepath": "fastapi/sse.py",
"start_line": "151"
} | {"status": "error", "error_type": "FileReadError", "error_message": "'>' not supported between instances of 'int' and 'str'"}full{"status": "error", "error_type": "FileReadError", "error_message": "'>' not supported between instances of 'int' and 'str'"} |
| 5 | run_command | {
"command": "cat fastapi/sse.py"
} | {"status": "ok", "stdout": "from typing import Annotated, Any\n\nfrom annotated_doc import Doc\nfrom pydantic import AfterValidator, BaseModel, Field, model_valfull{"status": "ok", "stdout": "from typing import Annotated, Any\n\nfrom annotated_doc import Doc\nfrom pydantic import AfterValidator, BaseModel, Field, model_validator\nfrom starlette.responses import StreamingResponse\n\n# Canonical SSE event schema matching the OpenAPI 3.2 spec\n# (Section 4.14.4 \"Special Considerations for Server-Sent Events\")\n_SSE_EVENT_SCHEMA: dict[str, Any] = {\n \"type\": \"object\",\n \"properties\": {\n \"data\": {\"type\": \"string\"},\n \"event\": {\"type\": \"string\"},\n \"id\": {\"type\": \"string\"},\n \"retry\": {\"type\": \"integer\", \"minimum\": 0},\n },\n}\n\n\nclass EventSourceResponse(StreamingResponse):\n \"\"\"Streaming response with `text/event-stream` media type.\n\n Use as `response_class=EventSourceResponse` on a *path operation* that uses `yield`\n to enable Server Sent Events (SSE) responses.\n\n Works with **any HTTP method** (`GET`, `POST`, etc.), which makes it compatible\n with protocols like MCP that stream SSE over `POST`.\n\n The actual encoding logic lives in the FastAPI routing layer. This class\n serves mainly as a marker and sets the correct `Content-Type`.\n \"\"\"\n\n media_type = \"text/event-stream\"\n\n\ndef _check_id_no_null(v: str | None) -> str | None:\n if v is not None and \"\\0\" in v:\n raise ValueError(\"SSE 'id' must not contain null characters\")\n return v\n\n\nclass ServerSentEvent(BaseModel):\n \"\"\"Represents a single Server-Sent Event.\n\n When `yield`ed from a *path operation function* that uses\n `response_class=EventSourceResponse`, each `ServerSentEvent` is encoded\n into the [SSE wire format](https://html.spec.whatwg.org/multipage/server-sent-events.html#parsing-an-event-stream)\n (`text/event-stream`).\n\n If you yield a plain object (dict, Pydantic model, etc.) instead, it is\n automatically JSON-encoded and sent as the `data:` field.\n\n All `data` values **including plain string |
| 6 | run_command | {
"command": "tail -n +150 fastapi/sse.py"
} | {"status": "ok", "stdout": " Doc(\n \"\"\"\n Pre-serialized data string to use as the `data:` field.\n \"\"\"\n ),\n ] = None,\n event: Annotated[\n str | None,full{"status": "ok", "stdout": " Doc(\n \"\"\"\n Pre-serialized data string to use as the `data:` field.\n \"\"\"\n ),\n ] = None,\n event: Annotated[\n str | None,\n Doc(\n \"\"\"\n Optional event type name (`event:` field).\n \"\"\"\n ),\n ] = None,\n id: Annotated[\n str | None,\n Doc(\n \"\"\"\n Optional event ID (`id:` field).\n \"\"\"\n ),\n ] = None,\n retry: Annotated[\n int | None,\n Doc(\n \"\"\"\n Optional reconnection time in milliseconds (`retry:` field).\n \"\"\"\n ),\n ] = None,\n comment: Annotated[\n str | None,\n Doc(\n \"\"\"\n Optional comment line(s) (`:` prefix).\n \"\"\"\n ),\n ] = None,\n) -> bytes:\n \"\"\"Build SSE wire-format bytes from **pre-serialized** data.\n\n The result always ends with `\\n\\n` (the event terminator).\n \"\"\"\n lines: list[str] = []\n\n if comment is not None:\n for line in comment.splitlines():\n lines.append(f\": {line}\")\n\n if event is not None:\n lines.append(f\"event: {event}\")\n\n if data_str is not None:\n for line in data_str.splitlines():\n lines.append(f\"data: {line}\")\n\n if id is not None:\n lines.append(f\"id: {id}\")\n\n if retry is not None:\n lines.append(f\"retry: {retry}\")\n\n lines.append(\"\")\n lines.append(\"\")\n return \"\\n\".join(lines).encode(\"utf-8\")\n\n\n# Keep-alive comment, per the SSE spec recommendation\nKEEPALIVE_COMMENT = b\": ping\\n\\n\"\n\n# Seconds between keep-alive pings when a generator is idle.\n# Private but importable so tests can monkeypatch it.\n_PING_INTERVAL: float = 15.0\n", "stderr": "", "exit_code": 0} |
| 7 | run_command | {
"command": "grep -n \"def _check_id_no_null\" fastapi/sse.py"
} | {"status": "ok", "stdout": "36:def _check_id_no_null(v: str | None) -> str | None:\n", "stderr": "", "exit_code": 0}full{"status": "ok", "stdout": "36:def _check_id_no_null(v: str | None) -> str | None:\n", "stderr": "", "exit_code": 0} |
| 8 | run_command | {
"command": "cat -n fastapi/sse.py"
} | {"status": "ok", "stdout": " 1\tfrom typing import Annotated, Any\n 2\t\n 3\tfrom annotated_doc import Doc\n 4\tfrom pydantic import AfterValidator, BaseModel, full{"status": "ok", "stdout": " 1\tfrom typing import Annotated, Any\n 2\t\n 3\tfrom annotated_doc import Doc\n 4\tfrom pydantic import AfterValidator, BaseModel, Field, model_validator\n 5\tfrom starlette.responses import StreamingResponse\n 6\t\n 7\t# Canonical SSE event schema matching the OpenAPI 3.2 spec\n 8\t# (Section 4.14.4 \"Special Considerations for Server-Sent Events\")\n 9\t_SSE_EVENT_SCHEMA: dict[str, Any] = {\n 10\t \"type\": \"object\",\n 11\t \"properties\": {\n 12\t \"data\": {\"type\": \"string\"},\n 13\t \"event\": {\"type\": \"string\"},\n 14\t \"id\": {\"type\": \"string\"},\n 15\t \"retry\": {\"type\": \"integer\", \"minimum\": 0},\n 16\t },\n 17\t}\n 18\t\n 19\t\n 20\tclass EventSourceResponse(StreamingResponse):\n 21\t \"\"\"Streaming response with `text/event-stream` media type.\n 22\t\n 23\t Use as `response_class=EventSourceResponse` on a *path operation* that uses `yield`\n 24\t to enable Server Sent Events (SSE) responses.\n 25\t\n 26\t Works with **any HTTP method** (`GET`, `POST`, etc.), which makes it compatible\n 27\t with protocols like MCP that stream SSE over `POST`.\n 28\t\n 29\t The actual encoding logic lives in the FastAPI routing layer. This class\n 30\t serves mainly as a marker and sets the correct `Content-Type`.\n 31\t \"\"\"\n 32\t\n 33\t media_type = \"text/event-stream\"\n 34\t\n 35\t\n 36\tdef _check_id_no_null(v: str | None) -> str | None:\n 37\t if v is not None and \"\\0\" in v:\n 38\t raise ValueError(\"SSE 'id' must not contain null characters\")\n 39\t return v\n 40\t\n 41\t\n 42\tclass ServerSentEvent(BaseModel):\n 43\t \"\"\"Represents a single Server-Sent Event.\n 44\t\n 45\t When `yield`ed from a *path operation function* that uses\n 46\t `response_class=EventSourceResponse`, each |
| 9 | run_command | {
"command": "tail -n +131 fastapi/sse.py"
} | {"status": "ok", "stdout": " \"\"\"\n ),\n ] = None\n\n @model_validator(mode=\"after\")\n def _check_data_exclusive(self) -> \"ServerSentEvent\":\n if self.datfull{"status": "ok", "stdout": " \"\"\"\n ),\n ] = None\n\n @model_validator(mode=\"after\")\n def _check_data_exclusive(self) -> \"ServerSentEvent\":\n if self.data is not None and self.raw_data is not None:\n raise ValueError(\n \"Cannot set both 'data' and 'raw_data' on the same \"\n \"ServerSentEvent. Use 'data' for JSON-serialized payloads \"\n \"or 'raw_data' for pre-formatted strings.\"\n )\n return self\n\n\ndef format_sse_event(\n *,\n data_str: Annotated[\n str | None,\n Doc(\n \"\"\"\n Pre-serialized data string to use as the `data:` field.\n \"\"\"\n ),\n ] = None,\n event: Annotated[\n str | None,\n Doc(\n \"\"\"\n Optional event type name (`event:` field).\n \"\"\"\n ),\n ] = None,\n id: Annotated[\n str | None,\n Doc(\n \"\"\"\n Optional event ID (`id:` field).\n \"\"\"\n ),\n ] = None,\n retry: Annotated[\n int | None,\n Doc(\n \"\"\"\n Optional reconnection time in milliseconds (`retry:` field).\n \"\"\"\n ),\n ] = None,\n comment: Annotated[\n str | None,\n Doc(\n \"\"\"\n Optional comment line(s) (`:` prefix).\n \"\"\"\n ),\n ] = None,\n) -> bytes:\n \"\"\"Build SSE wire-format bytes from **pre-serialized** data.\n\n The result always ends with `\\n\\n` (the event terminator).\n \"\"\"\n lines: list[str] = []\n\n if comment is not None:\n for line in comment.splitlines():\n lines.append(f\": {line}\")\n\n if event is not None:\n lines.append(f\"event: {event}\")\n\n if data_str is not None:\n for line in data_str.splitlines():\n lines.append(f\"data: {line}\")\n\n if id is not None: |
| 10 | run_command | {
"command": "python3 -m pytest tests/test_sse.py"
} | {"status": "ok", "stdout": "============================= test session starts ==============================\nplatform linux -- Python 3.13.14, pytest-9.1.1, plfull{"status": "ok", "stdout": "============================= test session starts ==============================\nplatform linux -- Python 3.13.14, pytest-9.1.1, pluggy-1.6.0\ncodspeed: 5.0.3 (disabled, mode: walltime, callgraph: enabled, timer_resolution: 1.0ns)\nrootdir: /workspace\nconfigfile: pytest.ini (WARNING: ignoring pytest config in pyproject.toml!)\nplugins: anyio-4.15.1, sugar-1.1.1, inline-snapshot-0.35.4, timeout-2.4.0, xdist-3.8.0, codspeed-5.0.3, cov-7.1.0\ncollected 18 items\n\ntests/test_sse.py .................. [100%]\n\n=============================== warnings summary ===============================\n../../../../../../kaggle/tmp/envs/overlays/starlette-1.6.0-py3-none-any/starlette/testclient.py:53\n /kaggle/tmp/envs/overlays/starlette-1.6.0-py3-none-any/starlette/testclient.py:53: DeprecationWarning: The anyio.abc.BlockingPortal alias is deprecated, use anyio.from_thread.BlockingPortal instead.\n _PortalFactoryType = Callable[[], AbstractContextManager[anyio.abc.BlockingPortal]]\n\n-- Docs: https://docs.pytest.org/en/stable/how-to/capture-warnings.html\n======================== 18 passed, 1 warning in 2.87s =========================\n", "stderr": "", "exit_code": 0} |
| 11 | write_file | {
"content": "from fastapi import FastAPI\nfrom fastapi.sse import EventSourceResponse, ServerSentEvent\nfrom fastapi.testclient import TestClient\nimport pytest\n\napp = FastAPI()\n\n@app.get(\"/sse\")\nasync def sse_endpoint():\n yield ServerSentEvent(data=\"hello\", event=\"test\\nbreak\")\n\nclient = TestClient(app)\n\ndef test_sse_invalid_event_newline():\n with pytest.raises(ValueError) as excinfo:\n # We need to trigger the validation. \n # In FastAPI, ServerSentEvent is a Pydantic model, so it validates on instantiation.\n ServerSentEvent(data=\"hello\", event=\"test\\nbreak\")\n assert \"SSE 'event' must not contain newlines\" in str(excinfo.value)\n\ndef test_sse_invalid_id_newline():\n with pytest.raises(ValueError) as excinfo:\n ServerSentEvent(data=\"hello\", id=\"id1\\nbreak\")\n assert \"SSE 'id' must not contain newlines\" in str(excinfo.value)\n\ndef test_sse_valid_event():\n event = ServerSentEvent(data=\"hello\", event=\"test\")\n assert event.event == \"test\"\n\ndef test_sse_valid_id():\n event = ServerSentEvent(data=\"hello\", id=\"id1\")\n assert event.id == \"id1\"\n",
"filepath": "tests/test_sse_validation.py"
} | {"status": "ok", "filepath": "tests/test_sse_validation.py", "size": 1083}full{"status": "ok", "filepath": "tests/test_sse_validation.py", "size": 1083} |
| 12 | run_command | {
"command": "python3 -m pytest tests/test_sse_validation.py"
} | {"status": "error", "error_type": "CommandError", "error_message": "============================= test session starts ==============================\nplatform lfull{"status": "error", "error_type": "CommandError", "error_message": "============================= test session starts ==============================\nplatform linux -- Python 3.13.14, pytest-9.1.1, pluggy-1.6.0\ncodspeed: 5.0.3 (disabled, mode: walltime, callgraph: enabled, timer_resolution: 1.0ns)\nrootdir: /workspace\nconfigfile: pytest.ini (WARNING: ignoring pytest config in pyproject.toml!)\nplugins: anyio-4.15.1, sugar-1.1.1, inline-snapshot-0.35.4, timeout-2.4.0, xdist-3.8.0, codspeed-5.0.3, cov-7.1.0\ncollected 4 items\n\ntests/test_sse_validation.py FF.. [100%]\n\n=================================== FAILURES ===================================\n________________________ test_sse_invalid_event_newline ________________________\n\n def test_sse_invalid_event_newline():\n> with pytest.raises(ValueError) as excinfo:\n ^^^^^^^^^^^^^^^^^^^^^^^^^\nE Failed: DID NOT RAISE ValueError\n\ntests/test_sse_validation.py:15: Failed\n_________________________ test_sse_invalid_id_newline __________________________\n\n def test_sse_invalid_id_newline():\n> with pytest.raises(ValueError) as excinfo:\n ^^^^^^^^^^^^^^^^^^^^^^^^^\nE Failed: DID NOT RAISE ValueError\n\ntests/test_sse_validation.py:22: Failed\n=============================== warnings summary ===============================\n../../../../../../kaggle/tmp/envs/overlays/starlette-1.6.0-py3-none-any/starlette/testclient.py:53\n /kaggle/tmp/envs/overlays/starlette-1.6.0-py3-none-any/starlette/testclient.py:53: DeprecationWarning: The anyio.abc.BlockingPortal alias is deprecated, use anyio.from_thread.BlockingPortal instead.\n _PortalFactoryType = Callable[[], AbstractContextManager[anyio.abc.BlockingPortal]]\n\n-- Docs: https://docs.pytest.org/en/stable/how-to/capture-warnings.html\n=========================== short test summary info ============================\nFAILED tests/test_sse_validation.py::test_sse_invalid_event_newli |
| 13 | edit_file | {
"filepath": "fastapi/sse.py",
"new_string": "def _check_sse_no_newline(v: str | None, field_name: str) -> str | None:\n if v is not None and \"\\n\" in v:\n raise ValueError(f\"SSE '{field_name}' must not contain newlines\")\n return v\n\n\ndef _check_id_no_null(v: str | None) -> str | None:\n if v is not None and \"\\0\" in v:\n raise ValueError(\"SSE 'id' must not contain null characters\")\n return v\n",
"old_string": "def _check_id_no_null(v: str | None) -> str | None:\n if v is not None and \"\\0\" in v:\n raise ValueError(\"SSE 'id' must not contain null characters\")\n return v\n"
} | {"status": "ok", "filepath": "fastapi/sse.py", "occurrences": 1, "strategy": "exact", "diff": "--- a/fastapi/sse.py\n+++ b/fastapi/sse.py\n@@ -33,6 +33,12 @@\n full{"status": "ok", "filepath": "fastapi/sse.py", "occurrences": 1, "strategy": "exact", "diff": "--- a/fastapi/sse.py\n+++ b/fastapi/sse.py\n@@ -33,6 +33,12 @@\n media_type = \"text/event-stream\"\n \n \n+def _check_sse_no_newline(v: str | None, field_name: str) -> str | None:\n+ if v is not None and \"\\n\" in v:\n+ raise ValueError(f\"SSE '{field_name}' must not contain newlines\")\n+ return v\n+\n+\n def _check_id_no_null(v: str | None) -> str | None:\n if v is not None and \"\\0\" in v:\n raise ValueError(\"SSE 'id' must not contain null characters\")\n", "is_truncated": false} |
| 14 | edit_file | {
"filepath": "fastapi/sse.py",
"new_string": " event: Annotated[\n str | None,\n AfterValidator(lambda v: _check_sse_no_newline(v, \"event\")),\n Doc(\n \"\"\"\n Optional event type name.\n",
"old_string": " event: Annotated[\n str | None,\n Doc(\n \"\"\"\n Optional event type name.\n"
} | {"status": "ok", "filepath": "fastapi/sse.py", "occurrences": 1, "strategy": "exact", "diff": "--- a/fastapi/sse.py\n+++ b/fastapi/sse.py\n@@ -92,6 +92,7 @@\n ]full{"status": "ok", "filepath": "fastapi/sse.py", "occurrences": 1, "strategy": "exact", "diff": "--- a/fastapi/sse.py\n+++ b/fastapi/sse.py\n@@ -92,6 +92,7 @@\n ] = None\n event: Annotated[\n str | None,\n+ AfterValidator(lambda v: _check_sse_no_newline(v, \"event\")),\n Doc(\n \"\"\"\n Optional event type name.\n", "is_truncated": false} |
| 15 | edit_file | {
"filepath": "fastapi/sse.py",
"new_string": " id: Annotated[\n str | None,\n AfterValidator(lambda v: _check_sse_no_newline(v, \"id\")),\n AfterValidator(_check_id_no_null),\n Doc(\n \"\"\"\n Optional event ID.\n",
"old_string": " id: Annotated[\n str | None,\n AfterValidator(_check_id_no_null),\n Doc(\n \"\"\"\n Optional event ID.\n"
} | {"status": "ok", "filepath": "fastapi/sse.py", "occurrences": 1, "strategy": "exact", "diff": "--- a/fastapi/sse.py\n+++ b/fastapi/sse.py\n@@ -104,6 +104,7 @@\nfull{"status": "ok", "filepath": "fastapi/sse.py", "occurrences": 1, "strategy": "exact", "diff": "--- a/fastapi/sse.py\n+++ b/fastapi/sse.py\n@@ -104,6 +104,7 @@\n ] = None\n id: Annotated[\n str | None,\n+ AfterValidator(lambda v: _check_sse_no_newline(v, \"id\")),\n AfterValidator(_check_id_no_null),\n Doc(\n \"\"\"\n", "is_truncated": false} |
| 16 | run_command | {
"command": "python3 -m pytest tests/test_sse_validation.py"
} | {"status": "ok", "stdout": "============================= test session starts ==============================\nplatform linux -- Python 3.13.14, pytest-9.1.1, plfull{"status": "ok", "stdout": "============================= test session starts ==============================\nplatform linux -- Python 3.13.14, pytest-9.1.1, pluggy-1.6.0\ncodspeed: 5.0.3 (disabled, mode: walltime, callgraph: enabled, timer_resolution: 1.0ns)\nrootdir: /workspace\nconfigfile: pytest.ini (WARNING: ignoring pytest config in pyproject.toml!)\nplugins: anyio-4.15.1, sugar-1.1.1, inline-snapshot-0.35.4, timeout-2.4.0, xdist-3.8.0, codspeed-5.0.3, cov-7.1.0\ncollected 4 items\n\ntests/test_sse_validation.py .... [100%]\n\n=============================== warnings summary ===============================\n../../../../../../kaggle/tmp/envs/overlays/starlette-1.6.0-py3-none-any/starlette/testclient.py:53\n /kaggle/tmp/envs/overlays/starlette-1.6.0-py3-none-any/starlette/testclient.py:53: DeprecationWarning: The anyio.abc.BlockingPortal alias is deprecated, use anyio.from_thread.BlockingPortal instead.\n _PortalFactoryType = Callable[[], AbstractContextManager[anyio.abc.BlockingPortal]]\n\n-- Docs: https://docs.pytest.org/en/stable/how-to/capture-warnings.html\n======================== 4 passed, 1 warning in 17.67s =========================\n", "stderr": "", "exit_code": 0} |
| 17 | run_command | {
"command": "python3 -m pytest tests/test_sse.py"
} | {"status": "ok", "stdout": "============================= test session starts ==============================\nplatform linux -- Python 3.13.14, pytest-9.1.1, plfull{"status": "ok", "stdout": "============================= test session starts ==============================\nplatform linux -- Python 3.13.14, pytest-9.1.1, pluggy-1.6.0\ncodspeed: 5.0.3 (disabled, mode: walltime, callgraph: enabled, timer_resolution: 1.0ns)\nrootdir: /workspace\nconfigfile: pytest.ini (WARNING: ignoring pytest config in pyproject.toml!)\nplugins: anyio-4.15.1, sugar-1.1.1, inline-snapshot-0.35.4, timeout-2.4.0, xdist-3.8.0, codspeed-5.0.3, cov-7.1.0\ncollected 18 items\n\ntests/test_sse.py .................. [100%]\n\n=============================== warnings summary ===============================\n../../../../../../kaggle/tmp/envs/overlays/starlette-1.6.0-py3-none-any/starlette/testclient.py:53\n /kaggle/tmp/envs/overlays/starlette-1.6.0-py3-none-any/starlette/testclient.py:53: DeprecationWarning: The anyio.abc.BlockingPortal alias is deprecated, use anyio.from_thread.BlockingPortal instead.\n _PortalFactoryType = Callable[[], AbstractContextManager[anyio.abc.BlockingPortal]]\n\n-- Docs: https://docs.pytest.org/en/stable/how-to/capture-warnings.html\n======================== 18 passed, 1 warning in 2.12s =========================\n", "stderr": "", "exit_code": 0} |
| 18 | run_command | {
"command": "rm tests/test_sse_validation.py"
} | {"status": "ok", "stdout": "", "stderr": "", "exit_code": 0}full{"status": "ok", "stdout": "", "stderr": "", "exit_code": 0} |
| 19 | submit_patch | {} | {"status": "ok", "patch_size": 1093, "files_changed": 1}full{"status": "ok", "patch_size": 1093, "files_changed": 1} |
diff --git a/fastapi/sse.py b/fastapi/sse.py
index 901d82496..a42135784 100644
--- a/fastapi/sse.py
+++ b/fastapi/sse.py
@@ -33,6 +33,12 @@ class EventSourceResponse(StreamingResponse):
media_type = "text/event-stream"
+def _check_sse_no_newline(v: str | None, field_name: str) -> str | None:
+ if v is not None and "\n" in v:
+ raise ValueError(f"SSE '{field_name}' must not contain newlines")
+ return v
+
+
def _check_id_no_null(v: str | None) -> str | None:
if v is not None and "\0" in v:
raise ValueError("SSE 'id' must not contain null characters")
@@ -86,6 +92,7 @@ class ServerSentEvent(BaseModel):
] = None
event: Annotated[
str | None,
+ AfterValidator(lambda v: _check_sse_no_newline(v, "event")),
Doc(
"""
Optional event type name.
@@ -97,6 +104,7 @@ class ServerSentEvent(BaseModel):
] = None
id: Annotated[
str | None,
+ AfterValidator(lambda v: _check_sse_no_newline(v, "id")),
AfterValidator(_check_id_no_null),
Doc(
"""
..........F
=================================== FAILURES ===================================
_ test_server_sent_event_single_line_fields_reject_newlines[first\nsecond-event] _
field_name = 'event', value = 'first\nsecond'
@pytest.mark.parametrize("field_name", ["event", "id"])
@pytest.mark.parametrize("value", ["first\nsecond", "first\rsecond", "first\r\nsecond"])
def test_server_sent_event_single_line_fields_reject_newlines(
field_name: str, value: str
):
> with pytest.raises(ValueError, match=f"SSE '{field_name}' must be a single line"):
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
E AssertionError: Regex pattern did not match.
E Expected regex: "SSE 'event' must be a single line"
E Actual message: "1 validation error for ServerSentEvent\nevent\n Value error, SSE 'event' must not contain newlines [type=value_error, input_value='first\\nsecond', input_type=str]\n For further information visit https://errors.pydantic.dev/2.13/v/value_error"
tests/test_sse.py:229: AssertionError
=============================== warnings summary ===============================
../../../../../../kaggle/tmp/envs/overlays/starlette-1.6.0-py3-none-any/starlette/testclient.py:53
/kaggle/tmp/envs/overlays/starlette-1.6.0-py3-none-any/starlette/testclient.py:53: DeprecationWarning: The anyio.abc.BlockingPortal alias is deprecated, use anyio.from_thread.BlockingPortal instead.
_PortalFactoryType = Callable[[], AbstractContextManager[anyio.abc.BlockingPortal]]
-- Docs: https://docs.pytest.org/en/stable/how-to/capture-warnings.html
!!!!!!!!!!!!!!!!!!!!!!!!!! stopping after 1 failures !!!!!!!!!!!!!!!!!!!!!!!!!!!
1 failed, 10 passed, 1 warning in 0.79s