refactor: Implement unified search abstraction, MemoryState refactoring, error handling, and unit test expansion

server/src/handlers/ast.rs

@@ -196,3 +196,54 @@ impl McpTool for ReplaceAstNodeHandler {
         Ok(result)
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use serde_json::json;
+    use tempfile::tempdir;
+
+    #[tokio::test]
+    async fn test_read_file_skeleton() {
+        let dir = tempdir().unwrap();
+        let state = Arc::new(MemoryState::new(dir.path().to_str().unwrap()));
+        let file_path = dir.path().join("test_skeleton.rs");
+        
+        let code = "fn my_func() {\n    let x = 1;\n}\n\nstruct MyStruct {\n    val: i32\n}";
+        std::fs::write(&file_path, code).unwrap();
+
+        let handler = ReadFileSkeletonHandler;
+        let args = json!({
+            "file_path": file_path.to_str().unwrap()
+        });
+
+        let res = handler.execute(args, state.clone()).await.unwrap();
+        assert!(res.contains("fn my_func()"));
+        assert!(res.contains("struct MyStruct"));
+    }
+
+    #[tokio::test]
+    async fn test_replace_ast_node() {
+        let dir = tempdir().unwrap();
+        let state = Arc::new(MemoryState::new(dir.path().to_str().unwrap()));
+        let file_path = dir.path().join("test_replace.rs");
+        
+        let code = "fn my_func() {\n    let x = 1;\n}\n\nstruct MyStruct {\n    val: i32\n}";
+        std::fs::write(&file_path, code).unwrap();
+
+        let handler = ReplaceAstNodeHandler;
+        let args = json!({
+            "file_path": file_path.to_str().unwrap(),
+            "node_type": "function_item",
+            "node_name": "my_func",
+            "new_content": "fn my_func() {\n    let x = 2;\n}"
+        });
+
+        let res = handler.execute(args, state.clone()).await.unwrap();
+        assert!(res.contains("Successfully replaced node"));
+
+        let new_code = std::fs::read_to_string(&file_path).unwrap();
+        assert!(new_code.contains("let x = 2;"));
+        assert!(!new_code.contains("let x = 1;"));
+    }
+}