a few changes to make A/B testing easier

app/fileSender.js

@@ -0,0 +1,146 @@
+import Nanobus from 'nanobus';
+import { arrayToHex, bytes } from './utils';
+
+export default class FileSender extends Nanobus {
+  constructor(file) {
+    super('FileSender');
+    this.file = file;
+    this.msg = 'importingFile';
+    this.progress = [0, 1];
+    this.cancelled = false;
+    this.iv = window.crypto.getRandomValues(new Uint8Array(12));
+    this.uploadXHR = new XMLHttpRequest();
+    this.key = window.crypto.subtle.generateKey(
+      {
+        name: 'AES-GCM',
+        length: 128
+      },
+      true,
+      ['encrypt']
+    );
+  }
+
+  static delete(id, token) {
+    return new Promise((resolve, reject) => {
+      if (!id || !token) {
+        return reject();
+      }
+      const xhr = new XMLHttpRequest();
+      xhr.open('POST', `/api/delete/${id}`);
+      xhr.setRequestHeader('Content-Type', 'application/json');
+
+      xhr.onreadystatechange = () => {
+        if (xhr.readyState === XMLHttpRequest.DONE) {
+          resolve();
+        }
+      };
+
+      xhr.send(JSON.stringify({ delete_token: token }));
+    });
+  }
+
+  get progressRatio() {
+    return this.progress[0] / this.progress[1];
+  }
+
+  get sizes() {
+    return {
+      partialSize: bytes(this.progress[0]),
+      totalSize: bytes(this.progress[1])
+    };
+  }
+
+  cancel() {
+    this.cancelled = true;
+    if (this.msg === 'fileSizeProgress') {
+      this.uploadXHR.abort();
+    }
+  }
+
+  readFile() {
+    return new Promise((resolve, reject) => {
+      const reader = new FileReader();
+      reader.readAsArrayBuffer(this.file);
+      reader.onload = function(event) {
+        const plaintext = new Uint8Array(this.result);
+        resolve(plaintext);
+      };
+      reader.onerror = function(err) {
+        reject(err);
+      };
+    });
+  }
+
+  uploadFile(encrypted, keydata) {
+    return new Promise((resolve, reject) => {
+      const file = this.file;
+      const id = arrayToHex(this.iv);
+      const dataView = new DataView(encrypted);
+      const blob = new Blob([dataView], { type: file.type });
+      const fd = new FormData();
+      fd.append('data', blob, file.name);
+
+      const xhr = this.uploadXHR;
+
+      xhr.upload.addEventListener('progress', e => {
+        if (e.lengthComputable) {
+          this.progress = [e.loaded, e.total];
+          this.emit('progress', this.progress);
+        }
+      });
+
+      xhr.onreadystatechange = () => {
+        if (xhr.readyState === XMLHttpRequest.DONE) {
+          if (xhr.status === 200) {
+            this.progress = [1, 1];
+            this.msg = 'notifyUploadDone';
+            const responseObj = JSON.parse(xhr.responseText);
+            return resolve({
+              url: responseObj.url,
+              id: responseObj.id,
+              secretKey: keydata.k,
+              deleteToken: responseObj.delete
+            });
+          }
+          this.msg = 'errorPageHeader';
+          reject(new Error(xhr.status));
+        }
+      };
+
+      xhr.open('post', '/api/upload', true);
+      xhr.setRequestHeader(
+        'X-File-Metadata',
+        JSON.stringify({
+          id: id,
+          filename: encodeURIComponent(file.name)
+        })
+      );
+      xhr.send(fd);
+      this.msg = 'fileSizeProgress';
+    });
+  }
+
+  async upload() {
+    const key = await this.key;
+    const plaintext = await this.readFile();
+    if (this.cancelled) {
+      throw new Error(0);
+    }
+    this.msg = 'encryptingFile';
+    this.emit('encrypting');
+    const encrypted = await window.crypto.subtle.encrypt(
+      {
+        name: 'AES-GCM',
+        iv: this.iv,
+        tagLength: 128
+      },
+      key,
+      plaintext
+    );
+    if (this.cancelled) {
+      throw new Error(0);
+    }
+    const keydata = await window.crypto.subtle.exportKey('jwk', key);
+    return this.uploadFile(encrypted, keydata);
+  }
+}