feat: adds support for asyncIterators (via readable-stream@3 dependency)

package.json

@@ -68,6 +68,7 @@
     "onetime": "^5.1.0",
     "p-limit": "^2.2.0",
     "pumpify": "^2.0.0",
+    "readable-stream": "^3.4.0",
     "snakeize": "^0.1.0",
     "stream-events": "^1.0.1",
     "through2": "^3.0.0",

src/file.ts

@@ -1190,6 +1190,9 @@ class File extends ServiceObject<File> {
 
     // tslint:disable-next-line:no-any
     let validateStream: any; // Created later, if necessary.
+
+    // TODO: remove `through2` dependency in favor of native PassThrough
+    // once Node 8 support is discontinued
     const throughStream = streamEvents(through()) as Duplex;
 
     let crc32c = true;

system-test/storage.ts

@@ -2061,6 +2061,19 @@ describe('storage', () => {
       });
     });
 
+    it('should support readable[Symbol.asyncIterator]()', async () => {
+      const fileContents = fs.readFileSync(FILES.big.path);
+
+      const [file] = await bucket.upload(FILES.big.path);
+      const stream = file.createReadStream();
+      const chunks: Buffer[] = [];
+      for await (const chunk of stream) {
+        chunks.push(chunk);
+      }
+      const remoteContents = Buffer.concat(chunks).toString();
+      assert.strictEqual(String(fileContents), String(remoteContents));
+    });
+
     it('should download a file to memory', done => {
       const fileContents = fs.readFileSync(FILES.big.path);
       bucket.upload(FILES.big.path, (err: Error | null, file?: File | null) => {