fix: Edge throws unspecified error

run tests on FF

.travis.yml

@@ -5,6 +5,7 @@ addons:
       - google-chrome
     packages:
       - google-chrome-stable
+  firefox: latest
 language: node_js
 node_js:
   - "node"

karma.conf.js

@@ -53,7 +53,14 @@ module.exports = function (config) {
 
     // start these browsers
     // available browser launchers: https://npmjs.org/browse/keyword/karma-launcher
-    browsers: ['ChromeHeadless'],
+    browsers: ['ChromeHeadless', 'FirefoxHeadless'],
+
+    customLaunchers: {
+      FirefoxHeadless: {
+        base: 'Firefox',
+        flags: ['-headless']
+      }
+    },
 
     // Continuous Integration mode
     // if true, Karma captures browsers, runs the tests and exits

local-storage-poorlyfill.js

@@ -20,8 +20,6 @@
  *
  */
 
-/* global DOMException */
-
 // strict mode
 'use strict';
 
@@ -98,11 +96,9 @@
         supported = false
       }
     } catch (e) {
-      /* istanbul ignore next */
-      if (e instanceof DOMException) {
-        // access is denied for this document
-        supported = false
-      }
+      // chrome throws DOMException
+      // edge throws Unspecified error
+      supported = false
     }
 
     return supported

test/test.js

@@ -95,6 +95,23 @@ describe('localStorage poorlyfill', function () {
       })
     })
 
+    context('when using window.localStorage throws Unspecified error', function () {
+      before(function () {
+        // localStorage is disabled
+        sandbox.replaceGetter(window, 'localStorage', function () {
+          throw new Error()
+        })
+      })
+
+      after(function () {
+        sandbox.restore()
+      })
+
+      it('should return false', function () {
+        assert.isFalse(window.__localStorage._isSupported(), 'not supported')
+      })
+    })
+
     context('when window.localStorage is not an object', function () {
       before(function () {
         // localStorage is disabled