From 433b5426dae6012c58124cf7f57e6807d8edb04d Mon Sep 17 00:00:00 2001
From: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
Date: Thu, 17 Sep 2026 20:46:18 +0000
Subject: [PATCH] test: cover TaskHint hint selection dispatch, embedding
 ranking and encode retries (bug risk coverage gap)

---
 tests/agents/test_tool_use_agent_hints.py | 108 ++++++++++++++++++++++
 1 file changed, 108 insertions(+)
 create mode 100644 tests/agents/test_tool_use_agent_hints.py

diff --git a/tests/agents/test_tool_use_agent_hints.py b/tests/agents/test_tool_use_agent_hints.py
new file mode 100644
index 000000000..9ba8c2261
--- /dev/null
+++ b/tests/agents/test_tool_use_agent_hints.py
@@ -0,0 +1,108 @@
+import numpy as np
+import pandas as pd
+import pytest
+import requests
+
+from agentlab.agents.tool_use_agent.tool_use_agent import TaskHint
+
+HINT_DB = pd.DataFrame(
+    {
+        "task_name": ["task.a", "task.b", "task.c"],
+        "semantic_keys": ["forms", "search", "navigation"],
+        "hint": ["fill the form", "use the search bar", "use the back button"],
+    }
+)
+
+
+def make_hint(**kwargs) -> TaskHint:
+    hint_block = TaskHint(**kwargs)
+    hint_block.hint_db = HINT_DB.copy()
+    return hint_block
+
+
+def test_choose_hints_dispatches_to_each_mode(monkeypatch):
+    calls = {}
+
+    def record(name, value):
+        calls[name] = value
+        return [name]
+
+    for mode, expected_arg in [("llm", "the goal"), ("direct", "task.a"), ("emb", "the goal")]:
+        hint_block = make_hint(hint_retrieval_mode=mode)
+        monkeypatch.setattr(
+            hint_block, "choose_hints_llm", lambda llm, goal: record("llm", goal), raising=False
+        )
+        monkeypatch.setattr(
+            hint_block,
+            "choose_hints_direct",
+            lambda task_name: record("direct", task_name),
+            raising=False,
+        )
+        monkeypatch.setattr(
+            hint_block, "choose_hints_emb", lambda goal: record("emb", goal), raising=False
+        )
+
+        assert hint_block.choose_hints(None, "task.a", "the goal") == [mode]
+        assert calls[mode] == expected_arg
+
+
+def test_choose_hints_unknown_mode_raises():
+    hint_block = make_hint()
+    hint_block.hint_retrieval_mode = "unknown"
+
+    with pytest.raises(ValueError, match="Unknown hint retrieval mode: unknown"):
+        hint_block.choose_hints(None, "task.a", "the goal")
+
+
+def test_choose_hints_emb_returns_top_n(monkeypatch):
+    hint_block = make_hint(hint_retrieval_mode="emb", top_n=2)
+    hint_block.uniq_hints = HINT_DB.copy()
+    hint_block.hint_embeddings = np.eye(3)
+
+    monkeypatch.setattr(hint_block, "_encode", lambda texts, prompt="": np.array([[1.0, 0.0, 0.0]]))
+    monkeypatch.setattr(
+        hint_block, "_similarity", lambda texts1, texts2: np.array([[0.1, 0.9, 0.5]])
+    )
+
+    # sorted by increasing similarity, so the most relevant hint comes last
+    assert hint_block.choose_hints_emb("the goal") == ["use the back button", "use the search bar"]
+
+
+def test_encode_retries_then_returns(monkeypatch):
+    hint_block = make_hint(hint_retrieval_mode="emb")
+    attempts = []
+
+    class Response:
+        def json(self):
+            return {"embeddings": [[1.0, 2.0]]}
+
+    def post(url, json, timeout):
+        attempts.append(url)
+        if len(attempts) < 3:
+            raise requests.exceptions.Timeout("boom")
+        return Response()
+
+    monkeypatch.setattr(requests, "post", post)
+    monkeypatch.setattr("agentlab.agents.tool_use_agent.tool_use_agent.time.sleep", lambda s: None)
+
+    embeddings = hint_block._encode(["the goal"], prompt="task description")
+
+    assert len(attempts) == 3
+    np.testing.assert_allclose(embeddings, np.array([[1.0, 2.0]]))
+
+
+def test_encode_reraises_after_max_retries(monkeypatch):
+    hint_block = make_hint(hint_retrieval_mode="emb")
+    attempts = []
+
+    def post(url, json, timeout):
+        attempts.append(url)
+        raise requests.exceptions.ConnectionError("no server")
+
+    monkeypatch.setattr(requests, "post", post)
+    monkeypatch.setattr("agentlab.agents.tool_use_agent.tool_use_agent.time.sleep", lambda s: None)
+
+    with pytest.raises(requests.exceptions.ConnectionError):
+        hint_block._encode(["the goal"], max_retries=3)
+
+    assert len(attempts) == 3