Implemented multi-file upload/download

app/archive.js

@@ -0,0 +1,33 @@
+import { blobStream, concatStream } from './streams';
+
+export default class Archive {
+  constructor(files) {
+    this.files = Array.from(files);
+  }
+
+  get name() {
+    return this.files.length > 1 ? 'Send-Archive.zip' : this.files[0].name;
+  }
+
+  get type() {
+    return this.files.length > 1 ? 'send-archive' : this.files[0].type;
+  }
+
+  get size() {
+    return this.files.reduce((total, file) => total + file.size, 0);
+  }
+
+  get manifest() {
+    return {
+      files: this.files.map(file => ({
+        name: file.name,
+        size: file.size,
+        type: file.type
+      }))
+    };
+  }
+
+  get stream() {
+    return concatStream(this.files.map(file => blobStream(file)));
+  }
+}