[router] add deepseek tool parser (#9694)

Co-authored-by: Chang Su <chang.s.su@oracle.com>

sgl-router/tests/tool_parser_deepseek.rs

@@ -0,0 +1,183 @@
+//! DeepSeek V3 Parser Integration Tests
+
+use sglang_router_rs::tool_parser::{DeepSeekParser, ParseState, StreamResult, ToolParser};
+
+#[tokio::test]
+async fn test_deepseek_complete_parsing() {
+    let parser = DeepSeekParser::new();
+
+    // Test single tool call
+    let input = r#"Let me help you with that.
+<｜tool▁calls▁begin｜><｜tool▁call▁begin｜>function<｜tool▁sep｜>get_weather
+```json
+{"location": "Tokyo", "units": "celsius"}
+```<｜tool▁call▁end｜><｜tool▁calls▁end｜>
+The weather in Tokyo is..."#;
+
+    let result = parser.parse_complete(input).await.unwrap();
+    assert_eq!(result.len(), 1);
+    assert_eq!(result[0].function.name, "get_weather");
+
+    // Verify arguments
+    let args: serde_json::Value = serde_json::from_str(&result[0].function.arguments).unwrap();
+    assert_eq!(args["location"], "Tokyo");
+    assert_eq!(args["units"], "celsius");
+}
+
+#[tokio::test]
+async fn test_deepseek_multiple_tools() {
+    let parser = DeepSeekParser::new();
+
+    let input = r#"<｜tool▁calls▁begin｜>
+<｜tool▁call▁begin｜>function<｜tool▁sep｜>search
+```json
+{"query": "rust programming"}
+```<｜tool▁call▁end｜>
+<｜tool▁call▁begin｜>function<｜tool▁sep｜>translate
+```json
+{"text": "Hello World", "to": "ja"}
+```<｜tool▁call▁end｜>
+<｜tool▁calls▁end｜>"#;
+
+    let result = parser.parse_complete(input).await.unwrap();
+    assert_eq!(result.len(), 2);
+    assert_eq!(result[0].function.name, "search");
+    assert_eq!(result[1].function.name, "translate");
+}
+
+#[tokio::test]
+async fn test_deepseek_streaming() {
+    let parser = DeepSeekParser::new();
+    let mut state = ParseState::new();
+
+    // Simulate streaming chunks
+    let chunks = vec![
+        "<｜tool▁calls▁begin｜><｜tool▁call▁begin｜>",
+        "function<｜tool▁sep｜>get_weather\n",
+        "```json\n",
+        r#"{"location": "#,
+        r#""Beijing", "#,
+        r#""units": "metric"}"#,
+        "\n```<｜tool▁call▁end｜><｜tool▁calls▁end｜>",
+    ];
+
+    let mut found_name = false;
+    let mut found_complete = false;
+
+    for chunk in chunks {
+        let result = parser.parse_incremental(chunk, &mut state).await.unwrap();
+
+        match result {
+            StreamResult::ToolName { name, .. } => {
+                assert_eq!(name, "get_weather");
+                found_name = true;
+            }
+            StreamResult::ToolComplete(tool) => {
+                assert_eq!(tool.function.name, "get_weather");
+                found_complete = true;
+            }
+            _ => {}
+        }
+    }
+
+    assert!(found_name || found_complete);
+}
+
+#[tokio::test]
+async fn test_deepseek_nested_json() {
+    let parser = DeepSeekParser::new();
+
+    let input = r#"<｜tool▁calls▁begin｜><｜tool▁call▁begin｜>function<｜tool▁sep｜>process
+```json
+{
+    "data": {
+        "nested": {
+            "deep": [1, 2, 3]
+        }
+    }
+}
+```<｜tool▁call▁end｜><｜tool▁calls▁end｜>"#;
+
+    let result = parser.parse_complete(input).await.unwrap();
+    assert_eq!(result.len(), 1);
+    assert_eq!(result[0].function.name, "process");
+
+    let args: serde_json::Value = serde_json::from_str(&result[0].function.arguments).unwrap();
+    assert!(args["data"]["nested"]["deep"].is_array());
+}
+
+#[test]
+fn test_deepseek_format_detection() {
+    let parser = DeepSeekParser::new();
+
+    // Should detect DeepSeek format
+    assert!(parser.detect_format("<｜tool▁calls▁begin｜>"));
+    assert!(parser.detect_format("text with <｜tool▁calls▁begin｜> marker"));
+
+    // Should not detect other formats
+    assert!(!parser.detect_format("[TOOL_CALLS]"));
+    assert!(!parser.detect_format("<tool_call>"));
+    assert!(!parser.detect_format("plain text"));
+}
+
+#[tokio::test]
+async fn test_deepseek_malformed_json_handling() {
+    let parser = DeepSeekParser::new();
+
+    // Malformed JSON should be skipped
+    let input = r#"<｜tool▁calls▁begin｜>
+<｜tool▁call▁begin｜>function<｜tool▁sep｜>broken
+```json
+{invalid json}
+```<｜tool▁call▁end｜>
+<｜tool▁call▁begin｜>function<｜tool▁sep｜>valid
+```json
+{"key": "value"}
+```<｜tool▁call▁end｜>
+<｜tool▁calls▁end｜>"#;
+
+    let result = parser.parse_complete(input).await.unwrap();
+    // Only the valid tool call should be parsed
+    assert_eq!(result.len(), 1);
+    assert_eq!(result[0].function.name, "valid");
+}
+
+#[tokio::test]
+async fn test_normal_text_extraction() {
+    let parser = DeepSeekParser::new();
+
+    // Python extracts text before tool calls as normal_text
+    let input = r#"Let me help you with that.
+<｜tool▁calls▁begin｜><｜tool▁call▁begin｜>function<｜tool▁sep｜>get_weather
+```json
+{"location": "Tokyo"}
+```<｜tool▁call▁end｜><｜tool▁calls▁end｜>"#;
+
+    let result = parser.parse_complete(input).await.unwrap();
+    assert_eq!(result.len(), 1);
+    assert_eq!(result[0].function.name, "get_weather");
+
+    // TODO: Verify normal text extraction when parser returns it
+    // In Python: normal_text = "Let me help you with that."
+}
+
+#[tokio::test]
+async fn test_multiple_tool_calls() {
+    let parser = DeepSeekParser::new();
+
+    let input = r#"<｜tool▁calls▁begin｜>
+<｜tool▁call▁begin｜>function<｜tool▁sep｜>get_weather
+```json
+{"location": "Tokyo"}
+```<｜tool▁call▁end｜>
+<｜tool▁call▁begin｜>function<｜tool▁sep｜>get_weather
+```json
+{"location": "Paris"}
+```<｜tool▁call▁end｜>
+<｜tool▁calls▁end｜><｜end▁of▁sentence｜>"#;
+
+    let result = parser.parse_complete(input).await.unwrap();
+    assert_eq!(result.len(), 2);
+    assert_eq!(result[0].function.name, "get_weather");
+    assert_eq!(result[1].function.name, "get_weather");
+}