Add firebase functions genStreamEmpty, genStreamResultOnly, genStreamLargeData on index.js.

- Modify genStreamError.

Author: MustafaJadid2025

firebase-functions/src/androidTest/backend/functions/index.js

@@ -151,32 +151,19 @@ async function* generateText() {
 exports.genStream = functionsV2.https.onCall(async (request, response) => {
   if (request.acceptsStreaming) {
     for await (const chunk of generateText()) {
-      response.sendChunk({chunk});
+      response.sendChunk(chunk);
     }
   }
   return streamData.join(' ');
 });
 
 exports.genStreamError = functionsV2.https.onCall(
     async (request, response) => {
-      if (request.acceptsStreaming) {
-        for await (const chunk of generateText()) {
-          response.sendChunk({chunk});
-        }
-      }
-      throw new Error('BOOM');
+      // Note: The functions backend does not pass the error message to the
+      // client at this time.
+      throw Error("BOOM")
     });
 
-exports.genStreamNoReturn = functionsV2.https.onCall(
-    async (request, response) => {
-      if (request.acceptsStreaming) {
-        for await (const chunk of generateText()) {
-          response.sendChunk({chunk});
-        }
-      }
-    },
-);
-
 const weatherForecasts = {
   Toronto: { conditions: 'snowy', temperature: 25 },
   London: { conditions: 'rainy', temperature: 50 },
@@ -209,3 +196,36 @@ exports.genStreamWeather = functionsV2.https.onCall(
       }
       return {forecasts};
     });
+
+exports.genStreamEmpty = functionsV2.https.onCall(
+  async (request, response) => {
+    if (request.acceptsStreaming) {
+      // Send no chunks
+    }
+    // Implicitly return null.
+  }
+);
+
+exports.genStreamResultOnly = functionsV2.https.onCall(
+  async (request, response) => {
+    if (request.acceptsStreaming) {
+      // Do not send any chunks.
+    }
+    return "Only a result";
+  }
+);
+
+exports.genStreamLargeData = functionsV2.https.onCall(
+  async (request, response) => {
+    if (request.acceptsStreaming) {
+      const largeString = 'A'.repeat(10000);
+      const chunkSize = 1024;
+      for (let i = 0; i < largeString.length; i += chunkSize) {
+        const chunk = largeString.substring(i, i + chunkSize);
+        response.sendChunk(chunk);
+        await sleep(100);
+      }
+    }
+    return "Stream Completed";
+  }
+);