fix: getting data from session storage may throw

When operating in an environment without session storage, the
StorageManager should not throw on data retrieval.

Author: gyoshev

src/StorageManager.ts

@@ -35,10 +35,15 @@ export default class StorageManager {
       return alternateStorage[type][key]
     }
 
-    if (type === 'local') {
-      return localStorage[key]
-    } else {
-      return sessionStorage.getItem(key)
+    try {
+      if (type === 'local') {
+        return localStorage[key]
+      } else {
+        return sessionStorage.getItem(key)
+      }
+    } catch (e) {
+      storageEnabled[type] = false
+      return alternateStorage[type][key]
     }
   }
 

test/specs/StorageManager.test.ts

@@ -0,0 +1,59 @@
+import StorageManager from '../../src/StorageManager'
+
+describe(StorageManager, () => {
+  let key = ''
+
+  beforeEach(() => key = `key${Math.floor(Math.random() * 10000)}`)
+
+  afterEach(() => {
+    localStorage.clear()
+    sessionStorage.clear()
+    jest.resetAllMocks()
+  })
+
+  describe('localStorage', () => {
+    it('retrieves key from storage', () => {
+      localStorage[key] = 'foo'
+
+      expect(StorageManager.get(key, 'local')).toEqual('foo')
+    })
+
+    it('removes key from storage', () => {
+      localStorage[key] = 'foo'
+
+      StorageManager.remove(key)
+
+      expect(StorageManager.get(key, 'local')).toEqual(undefined)
+    })
+
+    it('falls back to alternate storage if storage is unavailable', () => {
+      jest.spyOn(Storage.prototype, 'getItem').mockImplementation(() => { throw 1 })
+
+      expect(StorageManager.get(key, 'local')).toEqual(undefined)
+
+      StorageManager.save(key, 'foo', 'local')
+
+      expect(StorageManager.get(key, 'local')).toEqual('foo')
+    })
+  })
+
+  describe('sessionStorage', () => {
+    it('removes key from storage', () => {
+      sessionStorage.setItem(key, 'foo')
+
+      StorageManager.remove(key)
+
+      expect(StorageManager.get(key, 'session')).toEqual(undefined)
+    })
+
+    it('falls back to alternate storage if storage is unavailable', () => {
+      jest.spyOn(Storage.prototype, 'getItem').mockImplementation(() => { throw 1 })
+
+      expect(StorageManager.get(key, 'session')).toEqual(undefined)
+
+      StorageManager.save(key, 'foo', 'session')
+
+      expect(StorageManager.get(key, 'session')).toEqual('foo')
+    })
+  })
+})