test: add edge case tests for llm request rules

tests/unit/service/test_llm_request_rules.py

@@ -150,3 +150,159 @@ def test_fill_missing_reasoning_content_thinking_disabled():
     next_request, applied_rules = apply_llm_request_rules(request)
 
     assert "FillMissingReasoningContentRule" not in applied_rules
+
+
+# ===== StripRequiredToolChoiceForReasoningRule 边界场景 =====
+
+
+def test_strip_tool_choice_not_triggered_when_reasoning_effort_empty_string():
+    """reasoning_effort 为空字符串时不触发 StripRequiredToolChoiceForReasoningRule。"""
+    request = llmApiUtil.OpenAIRequest(
+        model="deepseek-v4-pro",
+        messages=[llmApiUtil.OpenAIMessage.text(llmApiUtil.OpenaiApiRole.USER, "hello")],
+        tool_choice="required",
+        provider_params={"reasoning_effort": ""},
+    )
+
+    next_request, applied_rules = apply_llm_request_rules(request)
+
+    assert next_request.tool_choice == "required"
+    assert applied_rules == ()
+
+
+def test_strip_tool_choice_not_triggered_when_tool_choice_is_none():
+    """tool_choice 为 None 时不触发 StripRequiredToolChoiceForReasoningRule。"""
+    request = llmApiUtil.OpenAIRequest(
+        model="deepseek-v4-pro",
+        messages=[llmApiUtil.OpenAIMessage.text(llmApiUtil.OpenaiApiRole.USER, "hello")],
+        tool_choice=None,
+        provider_params={"reasoning_effort": "high"},
+    )
+
+    next_request, applied_rules = apply_llm_request_rules(request)
+
+    assert next_request.tool_choice is None
+    assert applied_rules == ()
+
+
+def test_strip_tool_choice_not_triggered_when_provider_params_empty():
+    """provider_params 为空字典时不触发 StripRequiredToolChoiceForReasoningRule。"""
+    request = llmApiUtil.OpenAIRequest(
+        model="deepseek-v4-pro",
+        messages=[llmApiUtil.OpenAIMessage.text(llmApiUtil.OpenaiApiRole.USER, "hello")],
+        tool_choice="required",
+        provider_params={},
+    )
+
+    next_request, applied_rules = apply_llm_request_rules(request)
+
+    assert next_request.tool_choice == "required"
+    assert applied_rules == ()
+
+
+# ===== FillMissingReasoningContentRule 边界场景 =====
+
+
+def test_fill_missing_reasoning_content_not_triggered_for_plain_assistant_message():
+    """纯文本 assistant 消息（无 tool_calls）的 reasoning_content=None 不应被补填。"""
+    plain_assistant_msg = llmApiUtil.OpenAIMessage(
+        role=llmApiUtil.OpenaiApiRole.ASSISTANT,
+        content="I am a plain response",
+        reasoning_content=None,
+        tool_calls=None,
+    )
+    request = llmApiUtil.OpenAIRequest(
+        model="deepseek-v4-pro",
+        messages=[
+            llmApiUtil.OpenAIMessage.text(llmApiUtil.OpenaiApiRole.USER, "hello"),
+            plain_assistant_msg,
+        ],
+        provider_params=THINKING_PARAMS,
+    )
+
+    next_request, applied_rules = apply_llm_request_rules(request)
+
+    assert "FillMissingReasoningContentRule" not in applied_rules
+    assistant_msgs = [m for m in next_request.messages if m.role == llmApiUtil.OpenaiApiRole.ASSISTANT]
+    assert assistant_msgs[0].reasoning_content is None
+
+
+def test_fill_missing_reasoning_content_not_triggered_when_provider_params_empty():
+    """provider_params 为空字典时不触发 FillMissingReasoningContentRule。"""
+    msg_no_rc = _make_assistant_tool_call_msg(reasoning_content=None)
+    request = llmApiUtil.OpenAIRequest(
+        model="deepseek-v4-pro",
+        messages=[
+            llmApiUtil.OpenAIMessage.text(llmApiUtil.OpenaiApiRole.USER, "hello"),
+            msg_no_rc,
+        ],
+        provider_params={},
+    )
+
+    next_request, applied_rules = apply_llm_request_rules(request)
+
+    assert "FillMissingReasoningContentRule" not in applied_rules
+    assistant_msgs = [m for m in next_request.messages if m.role == llmApiUtil.OpenaiApiRole.ASSISTANT]
+    assert assistant_msgs[0].reasoning_content is None
+
+
+def test_fill_missing_reasoning_content_not_triggered_when_thinking_is_string():
+    """thinking 为非 dict 值（如字符串）时不触发规则。"""
+    msg_no_rc = _make_assistant_tool_call_msg(reasoning_content=None)
+    request = llmApiUtil.OpenAIRequest(
+        model="deepseek-v4-pro",
+        messages=[
+            llmApiUtil.OpenAIMessage.text(llmApiUtil.OpenaiApiRole.USER, "hello"),
+            msg_no_rc,
+        ],
+        provider_params={"thinking": "enabled"},
+    )
+
+    next_request, applied_rules = apply_llm_request_rules(request)
+
+    assert "FillMissingReasoningContentRule" not in applied_rules
+
+
+# ===== 两条规则同时触发的组合场景 =====
+
+
+def test_both_rules_triggered_simultaneously():
+    """reasoning_effort + tool_choice="required" + thinking enabled + 缺失 reasoning_content，
+    两条规则应同时触发。"""
+    msg_no_rc = _make_assistant_tool_call_msg(reasoning_content=None)
+    request = llmApiUtil.OpenAIRequest(
+        model="deepseek-v4-pro",
+        messages=[
+            llmApiUtil.OpenAIMessage.text(llmApiUtil.OpenaiApiRole.USER, "hello"),
+            msg_no_rc,
+        ],
+        tool_choice="required",
+        provider_params={
+            "reasoning_effort": "high",
+            "thinking": {"type": "enabled"},
+        },
+    )
+
+    next_request, applied_rules = apply_llm_request_rules(request)
+
+    assert next_request.tool_choice is None
+    assert "StripRequiredToolChoiceForReasoningRule" in applied_rules
+    assert "FillMissingReasoningContentRule" in applied_rules
+    assistant_msgs = [m for m in next_request.messages if m.role == llmApiUtil.OpenaiApiRole.ASSISTANT]
+    assert assistant_msgs[0].reasoning_content == ""
+
+
+def test_no_rules_triggered_when_no_conditions_match():
+    """无任何规则匹配时，请求原样返回。"""
+    request = llmApiUtil.OpenAIRequest(
+        model="gpt-4o",
+        messages=[llmApiUtil.OpenAIMessage.text(llmApiUtil.OpenaiApiRole.USER, "hello")],
+        tool_choice="auto",
+        provider_params={},
+    )
+
+    next_request, applied_rules = apply_llm_request_rules(request)
+
+    assert next_request.tool_choice == "auto"
+    assert next_request.messages == request.messages
+    assert applied_rules == ()