Add assistant aggregator test for tool use with no argument

Author: ovistoica

test/voice_fn/mock_data.clj

@@ -111,6 +111,12 @@
     :model "gpt-4o-mini-2024-07-18"}
    :done])
 
+(def mock-tool-call-response-single-argument
+  [{:service_tier "default", :created 1738211745, :choices [{:finish_reason nil, :index 0, :logprobs nil, :delta {:role "assistant", :content nil, :refusal nil, :tool_calls [{:index 0, :type "function", :function {:arguments "", :name "end_call"}, :id "call_J9MSffmnxdPj8r28tNzCO8qj"}]}}], :system_fingerprint "fp_bd83329f63", :id "chatcmpl-AvGZFNfbFY8QqV8JXsIlWn3E9Yp2o", :object "chat.completion.chunk", :model "gpt-4o-mini-2024-07-18"}
+   {:service_tier "default", :created 1738211745, :choices [{:finish_reason nil, :index 0, :logprobs nil, :delta {:tool_calls [{:index 0, :function {:arguments "{}"}}]}}], :system_fingerprint "fp_bd83329f63", :id "chatcmpl-AvGZFNfbFY8QqV8JXsIlWn3E9Yp2o", :object "chat.completion.chunk", :model "gpt-4o-mini-2024-07-18"}
+   {:service_tier "default", :created 1738211745, :choices [{:finish_reason "tool_calls", :index 0, :logprobs nil, :delta {}}], :system_fingerprint "fp_bd83329f63", :id "chatcmpl-AvGZFNfbFY8QqV8JXsIlWn3E9Yp2o", :object "chat.completion.chunk", :model "gpt-4o-mini-2024-07-18"}
+   :done])
+
 (def twilio-start-event
   {:sequenceNumber "1"
    :streamSid "MZ48f5da1eae19d83dcc3782e4ed89a45d"

test/voice_fn/processors/llm_context_aggregator_test.clj

@@ -278,6 +278,44 @@
                                                                          :name "retrieve_latest_stock_data"}
                                                               :id "call_frPVnoe8ruDicw50T8sLHki7"
                                                               :type :function}]}]}))
+    (fact "Handles tool calls with no arguments"
+          (let [final-state (reduce (fn [current-state frame]
+                                      (let [[next-state] (sut/assistant-aggregator-transform
+                                                           current-state
+                                                           nil
+                                                           frame)]
+                                        next-state))
+                              sstate
+                              (map chunk->frame mock/mock-tool-call-response-single-argument))
+                ;; Final state after end frame
+                [next-state {:keys [out tool-write]}] (sut/assistant-aggregator-transform
+                                                        final-state
+                                                        nil
+                                                        (frame/llm-full-response-end true))
+                out-frame (first out)
+                tool-write-frame (first tool-write)]
+            next-state => {:content-aggregation nil
+                           :function-arguments nil
+                           :function-name nil
+                           :tool-call-id nil
+                           :llm/context {:messages [{:content "You are a helpful assistant"
+                                                     :role "assistant"}
+                                                    {:content "Hello there" :role "user"}
+                                                    {:role :assistant
+                                                     :tool_calls [{:function {:arguments "{}"
+                                                                              :name "end_call"}
+                                                                   :id "call_J9MSffmnxdPj8r28tNzCO8qj"
+                                                                   :type :function}]}]}}
+            (= out-frame tool-write-frame) => true
+
+            (:frame/type out-frame) => :frame.llm/context
+            (:frame/data out-frame) => {:messages [{:content "You are a helpful assistant" :role "assistant"}
+                                                   {:content "Hello there" :role "user"}
+                                                   {:role :assistant
+                                                    :tool_calls [{:function {:arguments "{}"
+                                                                             :name "end_call"}
+                                                                  :id "call_J9MSffmnxdPj8r28tNzCO8qj"
+                                                                  :type :function}]}]}))
     (fact
       "Handles system-config-change frames"
       (let [nc {:messages [{:role :system