community: Handling missing key in Google Trends API response. (#15864)

- **Description:** Handing response where _interest_over_time_ is
missing.
  - **Issue:** #15859
  - **Dependencies:** None

libs/community/langchain_community/utilities/google_trends.py

@@ -65,7 +65,12 @@ class GoogleTrendsAPIWrapper(BaseModel):
 
         total_results = []
         client = self.serp_search_engine(params)
-        total_results = client.get_dict()["interest_over_time"]["timeline_data"]
+        client_dict = client.get_dict()
+        total_results = (
+            client_dict["interest_over_time"]["timeline_data"]
+            if "interest_over_time" in client_dict
+            else None
+        )
 
         if not total_results:
             return "No good Trend Result was found"

libs/community/tests/integration_tests/utilities/test_google_trends.py

@@ -0,0 +1,33 @@
+"""Unit test for Google Trends API Wrapper."""
+import os
+from unittest.mock import patch
+
+from langchain_community.utilities.google_trends import GoogleTrendsAPIWrapper
+
+
+@patch("serpapi.SerpApiClient.get_json")
+def test_unexpected_response(mocked_serpapiclient):
+    os.environ["SERPAPI_API_KEY"] = "123abcd"
+    resp = {
+        "search_metadata": {
+            "id": "659f32ec36e6a9107b46b5b4",
+            "status": "Error",
+            "json_endpoint": "https://serpapi.com/searches/.../659f32ec36e6a9107b46b5b4.json",
+            "created_at": "2024-01-11 00:14:36 UTC",
+            "processed_at": "2024-01-11 00:14:36 UTC",
+            "google_trends_url": "https://trends.google.com/trends/api/explore?tz=420&req=%7B%22comparisonItem%22%3A%5B%7B%22keyword%22%3A%22Lego+building+trends+2022%22%2C%22geo%22%3A%22%22%2C%22time%22%3A%22today+12-m%22%7D%5D%2C%22category%22%3A0%2C%22property%22%3A%22%22%2C%22userConfig%22%3A%22%7BuserType%3A+%5C%22USER_TYPE_LEGIT_USER%5C%22%7D%22%7D",
+            "prettify_html_file": "https://serpapi.com/searches/.../659f32ec36e6a9107b46b5b4.prettify",
+            "total_time_taken": 90.14,
+        },
+        "search_parameters": {
+            "engine": "google_trends",
+            "q": "Lego building trends 2022",
+            "date": "today 12-m",
+            "tz": "420",
+            "data_type": "TIMESERIES",
+        },
+        "error": "We couldn't get valid ... Please try again later.",
+    }
+    mocked_serpapiclient.return_value = resp
+    tool = GoogleTrendsAPIWrapper()
+    tool.run("does not matter")