feat(cloud): harden multi-tenant runtime resources

tests/unit_tests/provider/runners/test_remote_stream_limits.py

@@ -0,0 +1,49 @@
+from __future__ import annotations
+
+import pytest
+
+from langbot.libs.deerflow_api.client import (
+    ERROR_BODY_MAX_BYTES,
+    _read_error_body,
+)
+from langbot.libs.deerflow_api.errors import DeerFlowAPIError
+from langbot.pkg.provider.runners.langflowapi import (
+    _MAX_LANGFLOW_LINE_CHARS,
+    _MAX_LANGFLOW_RESPONSE_BYTES,
+    _iter_limited_lines,
+    _read_limited_response,
+)
+
+
+class _ChunkedResponse:
+    def __init__(self, chunks: list[bytes]):
+        self._chunks = chunks
+
+    async def aiter_bytes(self, chunk_size=None):
+        del chunk_size
+        for chunk in self._chunks:
+            yield chunk
+
+
+@pytest.mark.asyncio
+async def test_langflow_rejects_oversized_stream_event():
+    response = _ChunkedResponse([b'x' * (_MAX_LANGFLOW_LINE_CHARS + 1)])
+
+    with pytest.raises(ValueError, match='event exceeds'):
+        await anext(_iter_limited_lines(response))
+
+
+@pytest.mark.asyncio
+async def test_langflow_rejects_oversized_blocking_response():
+    response = _ChunkedResponse([b'x' * (_MAX_LANGFLOW_RESPONSE_BYTES + 1)])
+
+    with pytest.raises(ValueError, match='response exceeds'):
+        await _read_limited_response(response)
+
+
+@pytest.mark.asyncio
+async def test_deerflow_rejects_oversized_error_body():
+    response = _ChunkedResponse([b'x' * (ERROR_BODY_MAX_BYTES + 1)])
+
+    with pytest.raises(DeerFlowAPIError, match='response exceeds'):
+        await _read_error_body(response)