google-common[patch]: Merge adjacent function results in google common

libs/langchain-google-common/src/chat_models.ts

@@ -111,11 +111,20 @@ class ChatConnection<AuthOptions> extends AbstractGoogleLLMConnection<
         baseMessageToContent(msg, input[i - 1], this.useSystemInstruction)
       )
       .reduce((acc, cur) => {
-        // Filter out the system content, since those don't belong
-        // in the actual content.
-        const hasNoSystem = cur.every((content) => content.role !== "system");
-        return hasNoSystem ? [...acc, ...cur] : acc;
-      }, []);
+        // Filter out the system content
+        if (cur.every((content) => content.role === "system")) {
+          return acc;
+        }
+
+        // Combine adjacent function messages
+        if (cur[0]?.role === "function" && acc.length > 0 && acc[acc.length - 1].role === "function") {
+          acc[acc.length - 1].parts = [...acc[acc.length - 1].parts, ...cur[0].parts];
+        } else {
+          acc.push(...cur);
+        }
+
+        return acc;
+      }, [] as GeminiContent[]);
   }
 
   formatSystemInstruction(