fix: guard runtime answers with knowledge retrieval

internal/ai/runtime/executor/knowledge_guard_test.go

@@ -0,0 +1,69 @@
+package executor
+
+import (
+	"strings"
+	"testing"
+
+	"cs-agent/internal/ai/rag"
+	"cs-agent/internal/ai/runtime/internal/impl/retrievers"
+	"cs-agent/internal/models"
+	"cs-agent/internal/pkg/enums"
+)
+
+func TestBuildKnowledgeGuardDecisionFallsBackWhenKnowledgeMisses(t *testing.T) {
+	agent := newKnowledgeGuardAgentFixture()
+	decision := buildKnowledgeGuardDecision(&agent, &retrievers.KnowledgeRetrieveResult{
+		KnowledgeBaseIDs: []int64{1},
+		FallbackMode:     enums.KnowledgeFallbackModeSuggestRetry,
+	})
+
+	if decision.FallbackReply != "当前知识库里没有找到足够明确的信息，你可以换个更具体的问法再试一次。" {
+		t.Fatalf("unexpected fallback reply: %q", decision.FallbackReply)
+	}
+	if len(decision.Instructions) != 0 {
+		t.Fatalf("expected no instructions on miss, got %d", len(decision.Instructions))
+	}
+}
+
+func TestBuildKnowledgeGuardDecisionUsesAgentFallbackMessage(t *testing.T) {
+	agent := newKnowledgeGuardAgentFixture()
+	agent.FallbackMessage = "请联系人工客服"
+	decision := buildKnowledgeGuardDecision(&agent, &retrievers.KnowledgeRetrieveResult{
+		KnowledgeBaseIDs: []int64{1},
+		FallbackMode:     enums.KnowledgeFallbackModeNoAnswer,
+	})
+
+	if decision.FallbackReply != "请联系人工客服" {
+		t.Fatalf("expected agent fallback message, got %q", decision.FallbackReply)
+	}
+}
+
+func TestBuildKnowledgeGuardDecisionInjectsStrictInstructionOnHit(t *testing.T) {
+	agent := newKnowledgeGuardAgentFixture()
+	decision := buildKnowledgeGuardDecision(&agent, &retrievers.KnowledgeRetrieveResult{
+		KnowledgeBaseIDs: []int64{1},
+		Hits: []rag.RetrieveResult{
+			{KnowledgeBaseID: 1, Score: 0.88},
+		},
+		AnswerMode:   enums.KnowledgeAnswerModeStrict,
+		FallbackMode: enums.KnowledgeFallbackModeNoAnswer,
+	})
+
+	if decision.FallbackReply != "" {
+		t.Fatalf("expected no fallback reply on hit, got %q", decision.FallbackReply)
+	}
+	if len(decision.Instructions) != 1 {
+		t.Fatalf("expected one instruction, got %d", len(decision.Instructions))
+	}
+	content := decision.Instructions[0].Content
+	if !strings.Contains(content, "只能依据后续提供的知识片段回答") {
+		t.Fatalf("unexpected strict instruction: %q", content)
+	}
+	if !strings.Contains(content, "当前知识库暂无明确信息。") {
+		t.Fatalf("expected fallback text in instruction, got %q", content)
+	}
+}
+
+func newKnowledgeGuardAgentFixture() models.AIAgent {
+	return models.AIAgent{}
+}