Created Storage service test

test/utils/services/Storage.test.js

@@ -0,0 +1,50 @@
+import * as sinon from 'sinon';
+import Storage from '../../../src/utils/services/Storage';
+
+describe('Storage', () => {
+  const localStorageMock = {
+    getItem: sinon.fake((key) => key === 'shlink.foo' ? JSON.stringify({ foo: 'bar' }) : null),
+    setItem: sinon.spy(),
+  };
+  let storage;
+
+  beforeEach(() => {
+    localStorageMock.getItem.resetHistory();
+    localStorageMock.setItem.resetHistory();
+
+    storage = new Storage(localStorageMock);
+  });
+
+  describe('set', () => {
+    it('writes an stringified representation of provided value in local storage', () => {
+      const value = { bar: 'baz' };
+
+      storage.set('foo', value);
+
+      expect(localStorageMock.setItem.callCount).toEqual(1);
+      expect(localStorageMock.setItem.getCall(0).args).toEqual([
+        'shlink.foo',
+        JSON.stringify(value),
+      ]);
+    });
+  });
+
+  describe('get', () => {
+    it('fetches item from local storage', () => {
+      storage.get('foo');
+      expect(localStorageMock.getItem.callCount).toEqual(1);
+    });
+
+    it('returns parsed value when requested value is found in local storage', () => {
+      const value = storage.get('foo');
+
+      expect(value).toEqual({ foo: 'bar' });
+    });
+
+    it('returns undefined when requested value is not found in local storage', () => {
+      const value = storage.get('bar');
+
+      expect(value).toBeUndefined();
+    });
+  });
+});