阶段4（上）：LangGraph、Function Calling、MCP（SDK 2.x）、Agent 评测与运维、Agent 设计专题；run_examples 设置 RUN_EXAMPLES=1

topics/ai/function-calling/examples/tool-loop/test_tool_loop.py

@@ -0,0 +1,43 @@
+# requires: pydantic, pytest
+import tool_loop as tl
+
+
+def setup_function():
+    tl.REFUNDS.clear()
+
+
+def test_happy_path_with_self_correction():
+    out = tl.run_agent(tl.ScriptedModel(tl.demo_script()), "退款", {"user_id": "u1"}, lambda n, a: True)
+    assert out["answer"].startswith("已为订单") and tl.REFUNDS == {"A1001": 199.0}
+
+
+def test_user_rejects_refund():
+    out = tl.run_agent(tl.ScriptedModel(tl.demo_script()), "退款", {"user_id": "u1"}, lambda n, a: False)
+    assert tl.REFUNDS == {} and out["trace"][2][2] == {"error": "用户拒绝执行该操作"}
+
+
+def test_other_users_order_hidden():
+    script = [{"role": "assistant", "tool_calls": [tl.call("c1", "get_order", {"order_id": "A1001"})]},
+              {"role": "assistant", "content": "没有找到订单"}]
+    out = tl.run_agent(tl.ScriptedModel(script), "查订单", {"user_id": "u2"}, lambda n, a: True)
+    assert out["trace"][0][2] == {"error": "订单不存在"}
+
+
+def test_amount_over_paid_rejected_and_unknown_tool():
+    script = [{"role": "assistant", "tool_calls": [
+                  tl.call("c1", "refund", {"order_id": "A1001", "amount": 500}),
+                  tl.call("c2", "drop_table", {})]},
+              {"role": "assistant", "content": "无法退款"}]
+    model = tl.ScriptedModel(script)
+    out = tl.run_agent(model, "退 500", {"user_id": "u1"}, lambda n, a: True)
+    assert "不能超过" in out["trace"][0][2]["error"] and "未知工具" in out["trace"][1][2]["error"]
+    # 两个工具结果都回传给了模型，并且 tool_call_id 对应
+    last = model.seen[-1]
+    assert [m["tool_call_id"] for m in last if m["role"] == "tool"] == ["c1", "c2"]
+
+
+def test_max_steps():
+    script = [{"role": "assistant", "tool_calls": [tl.call(f"c{i}", "get_order", {"order_id": "A1001"})]}
+              for i in range(10)]
+    out = tl.run_agent(tl.ScriptedModel(script), "x", {"user_id": "u1"}, lambda n, a: True, max_steps=3)
+    assert out["steps"] == 3 and "转人工" in out["answer"]