fix(functions): do not duplicate function when valid JSON is inside XML tags

pkg/functions/parse.go

@@ -1492,7 +1492,7 @@ func ParseFunctionCall(llmresult string, functionConfig FunctionsConfig) []FuncC
 	results := []FuncCallResults{}
 	llmResults := []string{}
 
-	returnResult := func(results []string) (result []FuncCallResults, e error) {
+	extractJSON := func(results []string) (result []FuncCallResults, e error) {
 		// As we have to change the result before processing, we can't stream the answer token-by-token (yet?)
 		result = make([]FuncCallResults, 0)
 
@@ -1593,7 +1593,7 @@ func ParseFunctionCall(llmresult string, functionConfig FunctionsConfig) []FuncC
 		if len(llmResults) == 0 {
 			llmResults = append(llmResults, llmresult)
 		}
-		results, _ = returnResult(llmResults)
+		results, _ = extractJSON(llmResults)
 	}
 
 	// Determine which XML format to use (if any)
@@ -1632,8 +1632,16 @@ func ParseFunctionCall(llmresult string, functionConfig FunctionsConfig) []FuncC
 		// But skip if JSONRegexMatch or ResponseRegex was used (they already extracted the content)
 		xmlResults, err := ParseXML(llmresult, xmlFormat)
 		if err == nil && len(xmlResults) > 0 {
-			xlog.Debug("Found additional XML tool calls alongside JSON", "xml_count", len(xmlResults))
-			results = append(results, xmlResults...)
+			// Check if JSON is inside XML tags, if so, skip it
+			for _, result := range xmlResults {
+				jsonResults, _ := extractJSON([]string{result.Name})
+				if len(jsonResults) > 0 {
+					xlog.Debug("Found valid JSON inside XML tags, skipping XML parsing", "json_count", len(jsonResults))
+				} else {
+					xlog.Debug("Found additional XML tool calls alongside JSON", "xml_count", len(xmlResults))
+					results = append(results, xmlResults...)
+				}
+			}
 		}
 	}
 

pkg/functions/parse_test.go

@@ -820,6 +820,23 @@ Final text`
 			Expect(results[0].Name).To(Equal("first"))
 			Expect(results[1].Name).To(Equal("second"))
 		})
+
+		It("should not duplicate parse JSON inside tool_call tags", func() {
+			// This test reproduces a bug where JSON inside <tool_call> tags
+			// gets parsed twice: once as JSON (correctly) and once as XML (incorrectly)
+			// The XML parser should not run when JSON parsing already found valid results
+			input := `<tool_call>
+{"name": "get_current_weather", "arguments": {"location": "Beijing", "unit": "celsius"}}
+</tool_call>`
+
+			results := ParseFunctionCall(input, functionConfig)
+			// Should only have 1 result, not 2 (one correct + one malformed)
+			Expect(results).To(HaveLen(1), "Should not create duplicate entries when JSON is inside XML tags")
+			Expect(results[0].Name).To(Equal("get_current_weather"))
+			Expect(results[0].Arguments).To(Equal(`{"location":"Beijing","unit":"celsius"}`))
+			// Verify the name is not the entire JSON object (which would indicate malformed XML parsing)
+			Expect(results[0].Name).NotTo(ContainSubstring(`{"name"`), "Function name should not contain JSON object")
+		})
 	})
 
 	Context("Iterative Parser (ChatMsgParser)", func() {