Support nested fenced blocks in stream fence tracking

internal/util/toolcalls_candidates.go

@@ -7,6 +7,8 @@ import (
 
 var toolCallPattern = regexp.MustCompile(`\{\s*["']tool_calls["']\s*:\s*\[(.*?)\]\s*\}`)
 var fencedJSONPattern = regexp.MustCompile("(?s)```(?:json)?\\s*(.*?)\\s*```")
+var fencedCodeBlockPattern = regexp.MustCompile("(?s)```[\\s\\S]*?```")
+var markupToolSyntaxPattern = regexp.MustCompile(`(?i)<(?:(?:[a-z0-9_:-]+:)?(?:tool_call|function_call|invoke)\b|(?:[a-z0-9_:-]+:)?function_calls\b|(?:[a-z0-9_:-]+:)?tool_use\b)`)
 
 func buildToolCallCandidates(text string) []string {
 	trimmed := strings.TrimSpace(text)
@@ -173,3 +175,22 @@ func looksLikeToolExampleContext(text string) bool {
 	}
 	return strings.Contains(t, "```")
 }
+
+func shouldSkipToolCallParsingForCodeFenceExample(text string) bool {
+	if !looksLikeToolCallSyntax(text) || looksLikeMarkupToolSyntax(text) {
+		return false
+	}
+	stripped := strings.TrimSpace(stripFencedCodeBlocks(text))
+	return !looksLikeToolCallSyntax(stripped)
+}
+
+func looksLikeMarkupToolSyntax(text string) bool {
+	return markupToolSyntaxPattern.MatchString(text)
+}
+
+func stripFencedCodeBlocks(text string) string {
+	if text == "" {
+		return ""
+	}
+	return fencedCodeBlockPattern.ReplaceAllString(text, " ")
+}

internal/util/toolcalls_parse.go

@@ -26,6 +26,9 @@ func ParseToolCallsDetailed(text string, availableToolNames []string) ToolCallPa
 		return result
 	}
 	result.SawToolCallSyntax = looksLikeToolCallSyntax(text)
+	if shouldSkipToolCallParsingForCodeFenceExample(text) {
+		return result
+	}
 
 	candidates := buildToolCallCandidates(text)
 	var parsed []ParsedToolCall
@@ -74,6 +77,9 @@ func ParseStandaloneToolCallsDetailed(text string, availableToolNames []string)
 		return result
 	}
 	result.SawToolCallSyntax = looksLikeToolCallSyntax(trimmed)
+	if shouldSkipToolCallParsingForCodeFenceExample(trimmed) {
+		return result
+	}
 	candidates := buildToolCallCandidates(trimmed)
 	var parsed []ParsedToolCall
 	for _, candidate := range candidates {
@@ -183,6 +189,9 @@ func parseToolCallsPayload(payload string) []ParsedToolCall {
 	switch v := decoded.(type) {
 	case map[string]any:
 		if tc, ok := v["tool_calls"]; ok {
+			if isLikelyChatMessageEnvelope(v) {
+				return nil
+			}
 			return parseToolCallList(tc)
 		}
 		if parsed, ok := parseToolCallItem(v); ok {
@@ -194,6 +203,28 @@ func parseToolCallsPayload(payload string) []ParsedToolCall {
 	return nil
 }
 
+func isLikelyChatMessageEnvelope(v map[string]any) bool {
+	if v == nil {
+		return false
+	}
+	if _, ok := v["tool_calls"]; !ok {
+		return false
+	}
+	if role, ok := v["role"].(string); ok {
+		switch strings.ToLower(strings.TrimSpace(role)) {
+		case "assistant", "tool", "user", "system":
+			return true
+		}
+	}
+	if _, ok := v["tool_call_id"]; ok {
+		return true
+	}
+	if _, ok := v["content"]; ok {
+		return true
+	}
+	return false
+}
+
 func looksLikeToolCallSyntax(text string) bool {
 	lower := strings.ToLower(text)
 	return strings.Contains(lower, "tool_calls") ||

internal/util/toolcalls_test.go

@@ -19,11 +19,11 @@ func TestParseToolCalls(t *testing.T) {
 	}
 }
 
-func TestParseToolCallsFromFencedJSON(t *testing.T) {
+func TestParseToolCallsIgnoresFencedJSON(t *testing.T) {
 	text := "I will call tools now\n```json\n{\"tool_calls\":[{\"name\":\"search\",\"input\":{\"q\":\"news\"}}]}\n```"
 	calls := ParseToolCalls(text, []string{"search"})
-	if len(calls) != 1 {
-		t.Fatalf("expected fenced tool_call payload to be parsed, got %#v", calls)
+	if len(calls) != 0 {
+		t.Fatalf("expected fenced tool_call payload to be ignored, got %#v", calls)
 	}
 }
 
@@ -112,10 +112,17 @@ func TestParseStandaloneToolCallsSupportsMixedProsePayload(t *testing.T) {
 	}
 }
 
-func TestParseStandaloneToolCallsParsesFencedCodeBlock(t *testing.T) {
+func TestParseStandaloneToolCallsIgnoresFencedCodeBlock(t *testing.T) {
 	fenced := "```json\n{\"tool_calls\":[{\"name\":\"search\",\"input\":{\"q\":\"go\"}}]}\n```"
-	if calls := ParseStandaloneToolCalls(fenced, []string{"search"}); len(calls) != 1 {
-		t.Fatalf("expected fenced tool_call payload to be parsed, got %#v", calls)
+	if calls := ParseStandaloneToolCalls(fenced, []string{"search"}); len(calls) != 0 {
+		t.Fatalf("expected fenced tool_call payload to be ignored, got %#v", calls)
+	}
+}
+
+func TestParseStandaloneToolCallsIgnoresChatTranscriptEnvelope(t *testing.T) {
+	transcript := `[{"role":"user","content":"请展示完整会话"},{"role":"assistant","content":null,"tool_calls":[{"function":{"name":"search","arguments":"{\"q\":\"go\"}"}}]}]`
+	if calls := ParseStandaloneToolCalls(transcript, []string{"search"}); len(calls) != 0 {
+		t.Fatalf("expected transcript envelope not to trigger tool call parse, got %#v", calls)
 	}
 }
 

internal/util/util_edge_test.go

@@ -409,8 +409,8 @@ func TestParseToolCallsWithFunctionWrapper(t *testing.T) {
 func TestParseStandaloneToolCallsFencedCodeBlock(t *testing.T) {
 	fenced := "Here's an example:\n```json\n{\"tool_calls\":[{\"name\":\"search\",\"input\":{\"q\":\"go\"}}]}\n```\nDon't execute this."
 	calls := ParseStandaloneToolCalls(fenced, []string{"search"})
-	if len(calls) != 1 {
-		t.Fatalf("expected fenced code block to be parsed, got %d calls", len(calls))
+	if len(calls) != 0 {
+		t.Fatalf("expected fenced code block to be ignored, got %d calls", len(calls))
 	}
 }