refactor(fs): Handle legacy streams lacking Symbol.asyncIterator in Resource.setStream

Streams from older userland packages like readable-stream@2 (used by
replacestream) have .pipe but no Symbol.asyncIterator, causing
"stream is not async iterable" errors when the resource content is later
consumed by node:stream/consumers. Also handle WHATWG TransformStream
objects by unwrapping to their readable side.

Author: RandomByte

internal/e2e-tests/test/build.js

@@ -183,13 +183,6 @@ describe("ui5 build", () => {
 		await fs.writeFile(newControllerPath, newControllerContent, "utf-8");
 
 		// #2 Build
-		// FIXME: Currently failing here for IB (https://github.com/UI5/cli/pull/1267), April 02 2026 - aa3a2c1c04f7a5cd27650335cde37a798baacf2a
-		// Error message:
-		// ("Minification failed with error: Unexpected token punc «{», expected punc «,»
-		// in file /resources/application/a/controller/New.controller.js (line 4, col 16, pos 114)")
-		//
-		// -> Probably, the string replacement doesn't get executed as very first middleware
-		// (minify happens earlier unexpectedly)
 		await fixtureHelper.build(assert, ui5YamlName);
 
 		// Test: the placeholder in the source file is replaced in the dist output

packages/fs/lib/Resource.js

@@ -1,4 +1,4 @@
-import {Readable} from "node:stream";
+import {Readable, PassThrough} from "node:stream";
 import {buffer as streamToBuffer} from "node:stream/consumers";
 import ssri from "ssri";
 import clone from "clone";
@@ -528,6 +528,15 @@ class Resource {
 			this.#createStreamFactory = stream;
 			this.#contentType = CONTENT_TYPES.FACTORY;
 		} else {
+			if (stream instanceof TransformStream) {
+				stream = Readable.fromWeb(stream.readable);
+			} else if (!(Symbol.asyncIterator in stream)) {
+				// Legacy streams (e.g. from readable-stream@2) that lack Symbol.asyncIterator
+				// need to be wrapped in a native stream to be consumed by stream/consumers
+				const wrapper = new PassThrough();
+				stream.pipe(wrapper);
+				stream = wrapper;
+			}
 			this.#content = stream;
 			this.#contentType = CONTENT_TYPES.STREAM;
 		}

packages/fs/test/lib/Resource.js

@@ -743,6 +743,59 @@ test("Resource: clone resource with stream", async (t) => {
 	t.is(clonedResourceContent, "Content", "Cloned resource has correct content string");
 });
 
+test("Resource: clone resource with WHATWG TransformStream", async (t) => {
+	const ts = new TransformStream({
+		transform(chunk, controller) {
+			controller.enqueue(chunk);
+		}
+	});
+
+	const writer = ts.writable.getWriter();
+	writer.write(Buffer.from("TransformStream Content"));
+	writer.close();
+
+	const resource = new Resource({
+		path: "/my/path/to/resource"
+	});
+	resource.setStream(ts);
+
+	const clonedResource = await resource.clone();
+	t.pass("Resource cloned");
+
+	const clonedResourceContent = await clonedResource.getString();
+	t.is(clonedResourceContent, "TransformStream Content", "Cloned resource has correct content string");
+});
+
+test("Resource: clone resource with legacy stream lacking Symbol.asyncIterator", async (t) => {
+	// Simulate a stream from readable-stream@2 (e.g. replacestream) which has .pipe but no Symbol.asyncIterator
+	const stream = new Stream.Transform({
+		transform(chunk, enc, cb) {
+			cb(null, chunk.toString().replace("old", "new"));
+		}
+	});
+
+	// Remove Symbol.asyncIterator to simulate legacy readable-stream@2 behavior
+	stream[Symbol.asyncIterator] = undefined;
+	delete stream[Symbol.asyncIterator];
+
+	const input = new Stream.Readable();
+	input._read = function() {};
+	input.push("old content");
+	input.push(null);
+	input.pipe(stream);
+
+	const resource = new Resource({
+		path: "/my/path/to/resource"
+	});
+	resource.setStream(stream);
+
+	const clonedResource = await resource.clone();
+	t.pass("Resource cloned");
+
+	const clonedResourceContent = await clonedResource.getString();
+	t.is(clonedResourceContent, "new content", "Cloned resource has correct content string");
+});
+
 test("Resource: clone resource with createBuffer factory", async (t) => {
 	const resource = new Resource({
 		path: "/my/path/to/resource",