Fix HttpResponseBodyInit to support Node.js Readable streams

package.json

@@ -1,6 +1,6 @@
 {
     "name": "@azure/functions",
-    "version": "4.11.1",
+    "version": "4.11.2",
     "description": "Microsoft Azure Functions NodeJS Framework",
     "keywords": [
         "azure",

src/constants.ts

@@ -1,6 +1,6 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT License.
 
-export const version = '4.11.1';
+export const version = '4.11.2';
 
 export const returnBindingKey = '$return';

test/http/HttpResponse.test.ts

@@ -6,6 +6,7 @@ import { Blob } from 'buffer';
 import * as chai from 'chai';
 import { expect } from 'chai';
 import * as chaiAsPromised from 'chai-as-promised';
+import { Readable } from 'stream';
 import { ReadableStream } from 'stream/web';
 import { HttpResponse } from '../../src/http/HttpResponse';
 
@@ -366,6 +367,39 @@ describe('HttpResponse', () => {
             });
             expect(await res.text()).to.equal('Stream content');
         });
+
+        it('Node.js Readable stream body', async () => {
+            // Create a Node.js Readable stream (common for HTTP streaming scenarios)
+            const readable = new Readable({
+                read() {
+                    this.push('Readable ');
+                    this.push('stream ');
+                    this.push('content');
+                    this.push(null); // Signal end of stream
+                },
+            });
+
+            const res = new HttpResponse({
+                body: readable,
+            });
+            expect(await res.text()).to.equal('Readable stream content');
+        });
+
+        it('Node.js Readable stream from async generator', async () => {
+            // Common pattern for HTTP streaming (e.g., AI chat responses)
+            function* generateChunks() {
+                yield 'Hello ';
+                yield 'from ';
+                yield 'stream';
+            }
+
+            const readable = Readable.from(generateChunks());
+
+            const res = new HttpResponse({
+                body: readable,
+            });
+            expect(await res.text()).to.equal('Hello from stream');
+        });
     });
 
     describe('HttpHeadersInit types', () => {

types/http.d.ts

@@ -2,6 +2,7 @@
 // Licensed under the MIT License.
 
 import { Blob } from 'buffer';
+import { Readable } from 'stream';
 import { ReadableStream } from 'stream/web';
 import { URLSearchParams } from 'url';
 import { FunctionOptions, FunctionOutput, FunctionResult, FunctionTrigger } from './index';
@@ -11,9 +12,11 @@ import { InvocationContext } from './InvocationContext';
  * Represents the body types that can be used in an HTTP response.
  * This is a local definition to avoid dependency on lib.dom.
  * Compatible with Node.js native Fetch API body types.
+ * Includes Node.js Readable streams for HTTP streaming scenarios.
  */
 export type HttpResponseBodyInit =
     | ReadableStream
+    | Readable
     | Blob
     | ArrayBufferView
     | ArrayBuffer