test: add more unit tests of tools (#315)

* test: add more test on test_tts.py

* test: add unit test of search and retriever in tools

* test: remove the main code of search.py

* test: add the travily_search unit test

* reformate the codes

* test: add unit tests of tools

* Added the pytest-asyncio dependency

* added the license header of test_tavily_search_api_wrapper.py

tests/unit/tools/test_search.py

@@ -0,0 +1,54 @@
+# Copyright (c) 2025 Bytedance Ltd. and/or its affiliates
+# SPDX-License-Identifier: MIT
+
+import os
+import pytest
+from unittest.mock import patch, MagicMock
+from src.tools.search import get_web_search_tool
+from src.config import SearchEngine
+
+
+class TestGetWebSearchTool:
+
+    @patch("src.tools.search.SELECTED_SEARCH_ENGINE", SearchEngine.TAVILY.value)
+    def test_get_web_search_tool_tavily(self):
+        tool = get_web_search_tool(max_search_results=5)
+        assert tool.name == "web_search"
+        assert tool.max_results == 5
+        assert tool.include_raw_content is True
+        assert tool.include_images is True
+        assert tool.include_image_descriptions is True
+
+    @patch("src.tools.search.SELECTED_SEARCH_ENGINE", SearchEngine.DUCKDUCKGO.value)
+    def test_get_web_search_tool_duckduckgo(self):
+        tool = get_web_search_tool(max_search_results=3)
+        assert tool.name == "web_search"
+        assert tool.max_results == 3
+
+    @patch("src.tools.search.SELECTED_SEARCH_ENGINE", SearchEngine.BRAVE_SEARCH.value)
+    @patch.dict(os.environ, {"BRAVE_SEARCH_API_KEY": "test_api_key"})
+    def test_get_web_search_tool_brave(self):
+        tool = get_web_search_tool(max_search_results=4)
+        assert tool.name == "web_search"
+        assert tool.search_wrapper.api_key == "test_api_key"
+
+    @patch("src.tools.search.SELECTED_SEARCH_ENGINE", SearchEngine.ARXIV.value)
+    def test_get_web_search_tool_arxiv(self):
+        tool = get_web_search_tool(max_search_results=2)
+        assert tool.name == "web_search"
+        assert tool.api_wrapper.top_k_results == 2
+        assert tool.api_wrapper.load_max_docs == 2
+        assert tool.api_wrapper.load_all_available_meta is True
+
+    @patch("src.tools.search.SELECTED_SEARCH_ENGINE", "unsupported_engine")
+    def test_get_web_search_tool_unsupported_engine(self):
+        with pytest.raises(
+            ValueError, match="Unsupported search engine: unsupported_engine"
+        ):
+            get_web_search_tool(max_search_results=1)
+
+    @patch("src.tools.search.SELECTED_SEARCH_ENGINE", SearchEngine.BRAVE_SEARCH.value)
+    @patch.dict(os.environ, {}, clear=True)
+    def test_get_web_search_tool_brave_no_api_key(self):
+        tool = get_web_search_tool(max_search_results=1)
+        assert tool.search_wrapper.api_key == ""