Move logic into a function

Author: dlarocque

packages/vertexai/src/requests/stream-reader.ts

@@ -63,17 +63,7 @@ async function getResponsePromise(
       return enhancedResponse;
     }
 
-    // The backend can send empty text parts, but if they are sent back (e.g. in a chat history) there
-    // will be an error. To prevent this, filter out the empty text part from responses.
-    if (value.candidates && value.candidates.length > 0) {
-      value.candidates.forEach(candidate => {
-        if (candidate.content) {
-          candidate.content.parts = candidate.content.parts.filter(
-            part => part.text !== ''
-          );
-        }
-      });
-    }
+    deleteEmptyTextParts(value);
     allResponses.push(value);
   }
 }
@@ -88,17 +78,7 @@ async function* generateResponseSequence(
       break;
     }
 
-    // The backend can send empty text parts, but if they are sent back (e.g. in a chat history) there
-    // will be an error. To prevent this, filter out the empty text part from responses.
-    if (value.candidates && value.candidates.length > 0) {
-      value.candidates.forEach(candidate => {
-        if (candidate.content) {
-          candidate.content.parts = candidate.content.parts.filter(
-            part => part.text !== ''
-          );
-        }
-      });
-    }
+    deleteEmptyTextParts(value);
     const enhancedResponse = createEnhancedContentResponse(value);
     yield enhancedResponse;
   }
@@ -226,3 +206,21 @@ export function aggregateResponses(
   }
   return aggregatedResponse;
 }
+
+/**
+ * The backend can send empty text parts, but if they are sent back (e.g. in a chat history) there
+ * will be an error. To prevent this, filter out the empty text part from responses.
+ *
+ * See: https://github.com/firebase/firebase-js-sdk/issues/8714
+ */
+export function deleteEmptyTextParts(response: GenerateContentResponse): void {
+  if (response.candidates) {
+    response.candidates.forEach(candidate => {
+      if (candidate.content && candidate.content.parts) {
+        candidate.content.parts = candidate.content.parts.filter(
+          part => part.text !== ''
+        );
+      }
+    });
+  }
+}