fix: functionResponse should be user role

PiperOrigin-RevId: 613650762

Author: yyyu-google

README.md

@@ -259,7 +259,7 @@ async function functionCallingGenerateContentStream() {
     contents: [
       {role: 'user', parts: [{text: 'What is the weather in Boston?'}]},
       {role: 'model', parts: [{functionCall: {name: 'get_current_weather', args: {'location': 'Boston'}}}]},
-      {role: 'model', parts: functionResponseParts}
+      {role: 'user', parts: functionResponseParts}
     ],
     tools: functionDeclarations,
   };

src/models/chat_session.ts

@@ -407,7 +407,7 @@ function assignRoleToPartsAndValidateSendMessageRequest(
   parts: Array<Part>
 ): Content[] {
   const userContent: Content = {role: constants.USER_ROLE, parts: []};
-  const functionContent: Content = {role: constants.MODEL_ROLE, parts: []};
+  const functionContent: Content = {role: constants.USER_ROLE, parts: []};
   let hasUserContent = false;
   let hasFunctionContent = false;
   for (const part of parts) {

system_test/end_to_end_sample_test.ts

@@ -367,7 +367,7 @@ describe('generateContentStream', () => {
       contents: [
         {role: 'user', parts: [{text: 'What is the weather in Boston?'}]},
         {role: 'model', parts: FUNCTION_CALL},
-        {role: 'model', parts: FUNCTION_RESPONSE_PART},
+        {role: 'user', parts: FUNCTION_RESPONSE_PART},
       ],
       tools: TOOLS_WITH_FUNCTION_DECLARATION,
     };
@@ -387,7 +387,7 @@ describe('generateContentStream', () => {
       contents: [
         {role: 'user', parts: [{text: 'What is the weather in Boston?'}]},
         {role: 'model', parts: FUNCTION_CALL},
-        {role: 'model', parts: FUNCTION_RESPONSE_PART},
+        {role: 'user', parts: FUNCTION_RESPONSE_PART},
       ],
       tools: TOOLS_WITH_FUNCTION_DECLARATION,
     };
@@ -534,7 +534,7 @@ describe('generateContent', () => {
       contents: [
         {role: 'user', parts: [{text: 'What is the weather in Boston?'}]},
         {role: 'model', parts: FUNCTION_CALL},
-        {role: 'model', parts: FUNCTION_RESPONSE_PART},
+        {role: 'user', parts: FUNCTION_RESPONSE_PART},
       ],
       tools: TOOLS_WITH_FUNCTION_DECLARATION,
     };
@@ -552,7 +552,7 @@ describe('generateContent', () => {
       contents: [
         {role: 'user', parts: [{text: 'What is the weather in Boston?'}]},
         {role: 'model', parts: FUNCTION_CALL},
-        {role: 'model', parts: FUNCTION_RESPONSE_PART},
+        {role: 'user', parts: FUNCTION_RESPONSE_PART},
       ],
       tools: TOOLS_WITH_FUNCTION_DECLARATION,
     };