fix(community): normalize max_results before handing it to Firecrawl and fastCRW (#6175)

* fix(community): normalize max_results before handing it to Firecrawl and fastCRW

* test(community): pin the explicit-null max_results shape

The parametrized `omitted` case reused None as its "key absent" marker, so
`extra["max_results"] = configured` never ran for None and the key-present,
value-null YAML shape never reached _coerce_max_results. Use a distinct
sentinel for absence and add an explicit-null case per provider.

---------

Co-authored-by: Willem Jiang <willem.jiang@gmail.com>

backend/packages/harness/deerflow/community/fastcrw/tools.py

@@ -1,4 +1,5 @@
 import json
+import logging
 import os
 
 from firecrawl import FirecrawlApp
@@ -7,11 +8,30 @@ from langchain.tools import tool
 from deerflow.community.url_safety import validate_public_http_url
 from deerflow.config import get_app_config
 
+logger = logging.getLogger(__name__)
+
 # fastCRW is a Firecrawl-compatible web data engine (single Rust binary; self-host
 # or cloud). Because the REST API is Firecrawl-compatible, this provider reuses the
 # Firecrawl client and only swaps the base URL. Cloud default points at the managed
 # service; override `base_url` in the tool config (or set CRW_API_URL) for self-host.
 DEFAULT_BASE_URL = "https://fastcrw.com/api"
+DEFAULT_MAX_RESULTS = 5
+
+
+def _coerce_max_results(value: object) -> int:
+    """Normalize the configured ``max_results`` before handing it to the client."""
+    if isinstance(value, bool) or (isinstance(value, float) and not value.is_integer()):
+        # int() accepts booleans and silently truncates a YAML value such as 3.5.
+        count = 0
+    else:
+        try:
+            count = int(value)  # type: ignore[call-overload]
+        except (TypeError, ValueError, OverflowError):
+            count = 0
+    if count <= 0:
+        logger.warning("Invalid fastCRW max_results=%r; using default %s", value, DEFAULT_MAX_RESULTS)
+        return DEFAULT_MAX_RESULTS
+    return count
 
 
 def _get_fastcrw_client(tool_name: str = "web_search") -> FirecrawlApp:
@@ -56,9 +76,9 @@ def web_search_tool(query: str) -> str:
     """
     try:
         config = get_app_config().get_tool_config("web_search")
-        max_results = 5
+        max_results = DEFAULT_MAX_RESULTS
         if config is not None:
-            max_results = config.model_extra.get("max_results", max_results)
+            max_results = _coerce_max_results(config.model_extra.get("max_results", max_results))
 
         client = _get_fastcrw_client("web_search")
         result = client.search(query, limit=max_results)

backend/packages/harness/deerflow/community/firecrawl/tools.py

@@ -34,6 +34,25 @@ async def _aclose_firecrawl_client(client: AsyncFirecrawlApp) -> None:
         logger.warning("Failed to close the Firecrawl async HTTP pool", exc_info=True)
 
 
+DEFAULT_MAX_RESULTS = 5
+
+
+def _coerce_max_results(value: object) -> int:
+    """Normalize the configured ``max_results`` before handing it to Firecrawl."""
+    if isinstance(value, bool) or (isinstance(value, float) and not value.is_integer()):
+        # int() accepts booleans and silently truncates a YAML value such as 3.5.
+        count = 0
+    else:
+        try:
+            count = int(value)  # type: ignore[call-overload]
+        except (TypeError, ValueError, OverflowError):
+            count = 0
+    if count <= 0:
+        logger.warning("Invalid Firecrawl max_results=%r; using default %s", value, DEFAULT_MAX_RESULTS)
+        return DEFAULT_MAX_RESULTS
+    return count
+
+
 def _get_firecrawl_client(tool_name: str = "web_search") -> AsyncFirecrawlApp:
     config = get_app_config().get_tool_config(tool_name)
     api_key = None
@@ -59,9 +78,9 @@ async def web_search_tool(query: str) -> str:
     client: AsyncFirecrawlApp | None = None
     try:
         config = get_app_config().get_tool_config("web_search")
-        max_results = 5
+        max_results = DEFAULT_MAX_RESULTS
         if config is not None:
-            max_results = config.model_extra.get("max_results", max_results)
+            max_results = _coerce_max_results(config.model_extra.get("max_results", max_results))
 
         client = _get_firecrawl_client("web_search")
         result = await client.search(query, limit=max_results)

backend/tests/test_fastcrw_tools.py

@@ -2,6 +2,7 @@
 
 import ipaddress
 import json
+import logging
 from unittest.mock import MagicMock, patch
 
 import pytest
@@ -190,3 +191,47 @@ class TestWebFetchTool:
             "http://10.0.0.5/dashboard",
             formats=["markdown"],
         )
+
+
+# `None` is itself a configured value (`max_results:` with nothing after it in YAML), so an absent key
+# needs its own sentinel — otherwise the key-present case is never built and never tested.
+_OMITTED = object()
+
+
+@pytest.mark.parametrize(
+    ("configured", "expected_limit", "warns"),
+    [
+        pytest.param(True, 5, True, id="bool"),
+        pytest.param(0, 5, True, id="zero"),
+        pytest.param(-3, 5, True, id="negative"),
+        pytest.param(3.5, 5, True, id="fractional"),
+        pytest.param("many", 5, True, id="non-numeric-string"),
+        pytest.param("8", 8, False, id="integer-string"),
+        pytest.param(7, 7, False, id="plain-int"),
+        pytest.param(None, 5, True, id="explicit-null"),
+        pytest.param(_OMITTED, 5, False, id="omitted"),
+    ],
+)
+@patch.dict("os.environ", {}, clear=True)
+@patch("deerflow.community.fastcrw.tools.FirecrawlApp")
+@patch("deerflow.community.fastcrw.tools.get_app_config")
+def test_search_normalizes_max_results_before_calling_the_client(mock_get_app_config, mock_fastcrw_cls, caplog, configured, expected_limit, warns):
+    search_config = MagicMock()
+    extra: dict[str, object] = {"api_key": "fastcrw-search-key"}
+    if configured is not _OMITTED:
+        extra["max_results"] = configured
+    search_config.model_extra = extra
+    mock_get_app_config.return_value.get_tool_config.return_value = search_config
+
+    mock_result = MagicMock()
+    mock_result.web = []
+    mock_fastcrw_cls.return_value.search.return_value = mock_result
+
+    from deerflow.community.fastcrw.tools import web_search_tool
+
+    with caplog.at_level(logging.WARNING, logger="deerflow.community.fastcrw.tools"):
+        result = web_search_tool.invoke({"query": "q"})
+
+    assert result == "[]"
+    mock_fastcrw_cls.return_value.search.assert_called_once_with("q", limit=expected_limit)
+    assert ("Invalid fastCRW max_results" in caplog.text) is warns

backend/tests/test_firecrawl_tools.py

@@ -279,3 +279,47 @@ class TestPerCallClientTeardown:
         result = await web_search_tool.ainvoke({"query": "test query"})
 
         assert result == "[]"
+
+
+# `None` is itself a configured value (`max_results:` with nothing after it in YAML), so an absent key
+# needs its own sentinel — otherwise the key-present case is never built and never tested.
+_OMITTED = object()
+
+
+@pytest.mark.parametrize(
+    ("configured", "expected_limit", "warns"),
+    [
+        pytest.param(True, 5, True, id="bool"),
+        pytest.param(0, 5, True, id="zero"),
+        pytest.param(-3, 5, True, id="negative"),
+        pytest.param(3.5, 5, True, id="fractional"),
+        pytest.param("many", 5, True, id="non-numeric-string"),
+        pytest.param("8", 8, False, id="integer-string"),
+        pytest.param(7, 7, False, id="plain-int"),
+        pytest.param(None, 5, True, id="explicit-null"),
+        pytest.param(_OMITTED, 5, False, id="omitted"),
+    ],
+)
+@patch("deerflow.community.firecrawl.tools.AsyncFirecrawlApp")
+@patch("deerflow.community.firecrawl.tools.get_app_config")
+@pytest.mark.anyio
+async def test_search_normalizes_max_results_before_calling_the_client(mock_get_app_config, mock_firecrawl_cls, caplog, configured, expected_limit, warns):
+    search_config = MagicMock()
+    extra: dict[str, object] = {"api_key": "firecrawl-search-key"}
+    if configured is not _OMITTED:
+        extra["max_results"] = configured
+    search_config.model_extra = extra
+    mock_get_app_config.return_value.get_tool_config.return_value = search_config
+
+    mock_result = MagicMock()
+    mock_result.web = []
+    mock_firecrawl_cls.return_value.search = AsyncMock(return_value=mock_result)
+
+    from deerflow.community.firecrawl.tools import web_search_tool
+
+    with caplog.at_level(logging.WARNING, logger="deerflow.community.firecrawl.tools"):
+        result = await web_search_tool.ainvoke({"query": "q"})
+
+    assert result == "[]"
+    mock_firecrawl_cls.return_value.search.assert_called_once_with("q", limit=expected_limit)
+    assert ("Invalid Firecrawl max_results" in caplog.text) is warns