Make text() accessor handle mixed-parts responses

packages/vertexai/src/requests/response-helpers.test.ts

@@ -40,54 +40,85 @@ const fakeResponseText: GenerateContentResponse = {
   ]
 };
 
+const functionCallPart1 = {
+  functionCall: {
+    name: 'find_theaters',
+    args: {
+      location: 'Mountain View, CA',
+      movie: 'Barbie'
+    }
+  }
+};
+
+const functionCallPart2 = {
+  functionCall: {
+    name: 'find_times',
+    args: {
+      location: 'Mountain View, CA',
+      movie: 'Barbie',
+      time: '20:00'
+    }
+  }
+};
+
 const fakeResponseFunctionCall: GenerateContentResponse = {
   candidates: [
     {
       index: 0,
       content: {
         role: 'model',
-        parts: [
-          {
-            functionCall: {
-              name: 'find_theaters',
-              args: {
-                location: 'Mountain View, CA',
-                movie: 'Barbie'
-              }
-            }
-          }
-        ]
+        parts: [functionCallPart1]
       }
     }
   ]
 };
 
 const fakeResponseFunctionCalls: GenerateContentResponse = {
+  candidates: [
+    {
+      index: 0,
+      content: {
+        role: 'model',
+        parts: [functionCallPart1, functionCallPart2]
+      }
+    }
+  ]
+};
+
+const fakeResponseMixed1: GenerateContentResponse = {
+  candidates: [
+    {
+      index: 0,
+      content: {
+        role: 'model',
+        parts: [{ text: 'some text' }, functionCallPart2]
+      }
+    }
+  ]
+};
+
+const fakeResponseMixed2: GenerateContentResponse = {
+  candidates: [
+    {
+      index: 0,
+      content: {
+        role: 'model',
+        parts: [functionCallPart1, { text: 'some text' }]
+      }
+    }
+  ]
+};
+
+const fakeResponseMixed3: GenerateContentResponse = {
   candidates: [
     {
       index: 0,
       content: {
         role: 'model',
         parts: [
-          {
-            functionCall: {
-              name: 'find_theaters',
-              args: {
-                location: 'Mountain View, CA',
-                movie: 'Barbie'
-              }
-            }
-          },
-          {
-            functionCall: {
-              name: 'find_times',
-              args: {
-                location: 'Mountain View, CA',
-                movie: 'Barbie',
-                time: '20:00'
-              }
-            }
-          }
+          { text: 'some text' },
+          functionCallPart1,
+          { text: ' and more text' }
         ]
       }
     }
@@ -109,19 +140,43 @@ describe('response-helpers methods', () => {
     it('good response text', async () => {
       const enhancedResponse = addHelpers(fakeResponseText);
       expect(enhancedResponse.text()).to.equal('Some text and some more text');
+      expect(enhancedResponse.functionCalls()).to.be.undefined;
     });
     it('good response functionCall', async () => {
       const enhancedResponse = addHelpers(fakeResponseFunctionCall);
+      expect(enhancedResponse.text()).to.equal('');
       expect(enhancedResponse.functionCalls()).to.deep.equal([
-        fakeResponseFunctionCall.candidates?.[0].content.parts[0].functionCall
+        functionCallPart1.functionCall
       ]);
     });
     it('good response functionCalls', async () => {
       const enhancedResponse = addHelpers(fakeResponseFunctionCalls);
+      expect(enhancedResponse.text()).to.equal('');
+      expect(enhancedResponse.functionCalls()).to.deep.equal([
+        functionCallPart1.functionCall,
+        functionCallPart2.functionCall
+      ]);
+    });
+    it('good response text/functionCall', async () => {
+      const enhancedResponse = addHelpers(fakeResponseMixed1);
+      expect(enhancedResponse.functionCalls()).to.deep.equal([
+        functionCallPart2.functionCall
+      ]);
+      expect(enhancedResponse.text()).to.equal('some text');
+    });
+    it('good response functionCall/text', async () => {
+      const enhancedResponse = addHelpers(fakeResponseMixed2);
+      expect(enhancedResponse.functionCalls()).to.deep.equal([
+        functionCallPart1.functionCall
+      ]);
+      expect(enhancedResponse.text()).to.equal('some text');
+    });
+    it('good response text/functionCall/text', async () => {
+      const enhancedResponse = addHelpers(fakeResponseMixed3);
       expect(enhancedResponse.functionCalls()).to.deep.equal([
-        fakeResponseFunctionCalls.candidates?.[0].content.parts[0].functionCall,
-        fakeResponseFunctionCalls.candidates?.[0].content.parts[1].functionCall
+        functionCallPart1.functionCall
       ]);
+      expect(enhancedResponse.text()).to.equal('some text and more text');
     });
     it('bad response safety', async () => {
       const enhancedResponse = addHelpers(badFakeResponse);

packages/vertexai/src/requests/response-helpers.ts

@@ -85,13 +85,19 @@ export function addHelpers(
 }
 
 /**
- * Returns text of first candidate.
+ * Returns all text found in all parts of first candidate.
  */
 export function getText(response: GenerateContentResponse): string {
-  if (response.candidates?.[0].content?.parts?.[0]?.text) {
-    return response.candidates[0].content.parts
-      .map(({ text }) => text)
-      .join('');
+  const textStrings = [];
+  if (response.candidates?.[0].content?.parts) {
+    for (const part of response.candidates?.[0].content?.parts) {
+      if (part.text) {
+        textStrings.push(part.text);
+      }
+    }
+  }
+  if (textStrings.length > 0) {
+    return textStrings.join('');
   } else {
     return '';
   }