a few changes to make A/B testing easier

app/utils.js

@@ -0,0 +1,156 @@
+function arrayToHex(iv) {
+  let hexStr = '';
+  // eslint-disable-next-line prefer-const
+  for (let i in iv) {
+    if (iv[i] < 16) {
+      hexStr += '0' + iv[i].toString(16);
+    } else {
+      hexStr += iv[i].toString(16);
+    }
+  }
+  return hexStr;
+}
+
+function hexToArray(str) {
+  const iv = new Uint8Array(str.length / 2);
+  for (let i = 0; i < str.length; i += 2) {
+    iv[i / 2] = parseInt(str.charAt(i) + str.charAt(i + 1), 16);
+  }
+
+  return iv;
+}
+
+function notify(str) {
+  return str;
+  /* TODO: enable once we have an opt-in ui element
+  if (!('Notification' in window)) {
+    return;
+  } else if (Notification.permission === 'granted') {
+    new Notification(str);
+  } else if (Notification.permission !== 'denied') {
+    Notification.requestPermission(function(permission) {
+      if (permission === 'granted') new Notification(str);
+    });
+  }
+  */
+}
+
+function loadShim(polyfill) {
+  return new Promise((resolve, reject) => {
+    const shim = document.createElement('script');
+    shim.src = polyfill;
+    shim.addEventListener('load', () => resolve(true));
+    shim.addEventListener('error', () => resolve(false));
+    document.head.appendChild(shim);
+  });
+}
+
+async function canHasSend(polyfill) {
+  try {
+    const key = await window.crypto.subtle.generateKey(
+      {
+        name: 'AES-GCM',
+        length: 128
+      },
+      true,
+      ['encrypt', 'decrypt']
+    );
+
+    await window.crypto.subtle.encrypt(
+      {
+        name: 'AES-GCM',
+        iv: window.crypto.getRandomValues(new Uint8Array(12)),
+        tagLength: 128
+      },
+      key,
+      new ArrayBuffer(8)
+    );
+    return true;
+  } catch (err) {
+    return loadShim(polyfill);
+  }
+}
+
+function isFile(id) {
+  return /^[0-9a-fA-F]{10}$/.test(id);
+}
+
+function copyToClipboard(str) {
+  const aux = document.createElement('input');
+  aux.setAttribute('value', str);
+  aux.contentEditable = true;
+  aux.readOnly = true;
+  document.body.appendChild(aux);
+  if (navigator.userAgent.match(/iphone|ipad|ipod/i)) {
+    const range = document.createRange();
+    range.selectNodeContents(aux);
+    const sel = window.getSelection();
+    sel.removeAllRanges();
+    sel.addRange(range);
+    aux.setSelectionRange(0, str.length);
+  } else {
+    aux.select();
+  }
+  const result = document.execCommand('copy');
+  document.body.removeChild(aux);
+  return result;
+}
+
+const LOCALIZE_NUMBERS = !!(
+  typeof Intl === 'object' &&
+  Intl &&
+  typeof Intl.NumberFormat === 'function' &&
+  typeof navigator === 'object'
+);
+
+const UNITS = ['B', 'kB', 'MB', 'GB'];
+function bytes(num) {
+  const exponent = Math.min(Math.floor(Math.log10(num) / 3), UNITS.length - 1);
+  const n = Number(num / Math.pow(1000, exponent));
+  const nStr = LOCALIZE_NUMBERS
+    ? n.toLocaleString(navigator.languages, {
+        minimumFractionDigits: 1,
+        maximumFractionDigits: 1
+      })
+    : n.toFixed(1);
+  return `${nStr}${UNITS[exponent]}`;
+}
+
+function percent(ratio) {
+  return LOCALIZE_NUMBERS
+    ? ratio.toLocaleString(navigator.languages, { style: 'percent' })
+    : `${Math.floor(ratio * 100)}%`;
+}
+
+function allowedCopy() {
+  const support = !!document.queryCommandSupported;
+  return support ? document.queryCommandSupported('copy') : false;
+}
+
+function delay(delay = 100) {
+  return new Promise(resolve => setTimeout(resolve, delay));
+}
+
+function fadeOut(id) {
+  const classes = document.getElementById(id).classList;
+  classes.remove('fadeIn');
+  classes.add('fadeOut');
+  return delay(300);
+}
+
+const ONE_DAY_IN_MS = 86400000;
+
+module.exports = {
+  fadeOut,
+  delay,
+  allowedCopy,
+  bytes,
+  percent,
+  copyToClipboard,
+  arrayToHex,
+  hexToArray,
+  notify,
+  canHasSend,
+  isFile,
+  ONE_DAY_IN_MS
+};