Add supportsUploadProgress() tests

packages/@uppy/core/src/supportsUploadProgress.js

@@ -1,8 +1,11 @@
 // Edge 15.x does not fire 'progress' events on uploads.
 // See https://github.com/transloadit/uppy/issues/945
 // And https://developer.microsoft.com/en-us/microsoft-edge/platform/issues/12224510/
-module.exports = function supportsUploadProgress () {
-  const userAgent = typeof navigator !== 'undefined' ? navigator.userAgent : null
+module.exports = function supportsUploadProgress (userAgent) {
+  // Allow passing in userAgent for tests
+  if (userAgent == null) {
+    userAgent = typeof navigator !== 'undefined' ? navigator.userAgent : null
+  }
   // Assume it works because basically everything supports progress events.
   if (!userAgent) return true
 
@@ -10,7 +13,9 @@ module.exports = function supportsUploadProgress () {
   if (!m) return true
 
   const edgeVersion = m[1]
-  const [major, minor] = edgeVersion.split('.')
+  let [major, minor] = edgeVersion.split('.')
+  major = parseInt(major, 10)
+  minor = parseInt(minor, 10)
 
   // Worked before:
   // Edge 40.15063.0.0
@@ -21,7 +26,7 @@ module.exports = function supportsUploadProgress () {
 
   // Fixed in:
   // Microsoft EdgeHTML 18.18218
-  if (major > 18 || (major === 18 && minor > 18218)) {
+  if (major > 18 || (major === 18 && minor >= 18218)) {
     return true
   }
 

packages/@uppy/core/src/supportsUploadProgress.test.js

@@ -0,0 +1,28 @@
+const supportsUploadProgress = require('./supportsUploadProgress')
+
+describe('supportsUploadProgress', () => {
+  it('returns true in working browsers', () => {
+    // Firefox 64 (dev edition)
+    expect(supportsUploadProgress('Mozilla/5.0 (X11; Linux x86_64; rv:64.0) Gecko/20100101 Firefox/64.0')).toBe(true)
+
+    // Chromium 70
+    expect(supportsUploadProgress('Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/70.0.3538.110 Safari/537.36')).toBe(true)
+
+    // IE 11
+    expect(supportsUploadProgress('Mozilla/5.0 (Windows NT 10.0; WOW64; Trident/7.0; .NET4.0C; .NET4.0E; rv:11.0) like Gecko')).toBe(true)
+
+    // MS Edge 14
+    expect(supportsUploadProgress('Chrome (AppleWebKit/537.1; Chrome50.0; Windows NT 6.3) AppleWebKit/537.36 (KHTML like Gecko) Chrome/51.0.2704.79 Safari/537.36 Edge/14.14393')).toBe(true)
+
+    // MS Edge 18, supposedly fixed
+    expect(supportsUploadProgress('Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/52.0.2743.116 Safari/537.36 Edge/18.18218')).toBe(true)
+  })
+
+  it('returns false in broken browsers', () => {
+    // MS Edge 15, first broken version
+    expect(supportsUploadProgress('Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/52.0.2743.116 Safari/537.36 Edge/15.15063')).toBe(false)
+
+    // MS Edge 17
+    expect(supportsUploadProgress('Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/64.0.3282.140 Safari/537.36 Edge/17.17134')).toBe(false)
+  })
+})