1 files changed, 91 insertions, 1 deletions
diff --git a/spec/javascripts/signin_tabs_memoizer_spec.js b/spec/javascripts/signin_tabs_memoizer_spec.js
index d83d9a57b42..0a32797c3e2 100644
--- a/spec/javascripts/signin_tabs_memoizer_spec.js
+++ b/spec/javascripts/signin_tabs_memoizer_spec.js
@@ -1,4 +1,6 @@
-require('~/signin_tabs_memoizer');
+import AccessorUtilities from '~/lib/utils/accessor';
+
+import '~/signin_tabs_memoizer';
 
 ((global) => {
   describe('SigninTabsMemoizer', () => {
@@ -19,6 +21,8 @@ require('~/signin_tabs_memoizer');
 
     beforeEach(() => {
       loadFixtures(fixtureTemplate);
+
+      spyOn(AccessorUtilities, 'isLocalStorageAccessSafe').and.returnValue(true);
     });
 
     it('does nothing if no tab was previously selected', () => {
@@ -49,5 +53,91 @@ require('~/signin_tabs_memoizer');
 
       expect(memo.readData()).toEqual('#standard');
     });
+
+    describe('class constructor', () => {
+      beforeEach(() => {
+        memo = createMemoizer();
+      });
+
+      it('should set .isLocalStorageAvailable', () => {
+        expect(AccessorUtilities.isLocalStorageAccessSafe).toHaveBeenCalled();
+        expect(memo.isLocalStorageAvailable).toBe(true);
+      });
+    });
+
+    describe('saveData', () => {
+      beforeEach(() => {
+        memo = {
+          currentTabKey,
+        };
+
+        spyOn(localStorage, 'setItem');
+      });
+
+      describe('if .isLocalStorageAvailable is `false`', () => {
+        beforeEach(function () {
+          memo.isLocalStorageAvailable = false;
+
+          global.ActiveTabMemoizer.prototype.saveData.call(memo);
+        });
+
+        it('should not call .setItem', () => {
+          expect(localStorage.setItem).not.toHaveBeenCalled();
+        });
+      });
+
+      describe('if .isLocalStorageAvailable is `true`', () => {
+        const value = 'value';
+
+        beforeEach(function () {
+          memo.isLocalStorageAvailable = true;
+
+          global.ActiveTabMemoizer.prototype.saveData.call(memo, value);
+        });
+
+        it('should call .setItem', () => {
+          expect(localStorage.setItem).toHaveBeenCalledWith(currentTabKey, value);
+        });
+      });
+    });
+
+    describe('readData', () => {
+      const itemValue = 'itemValue';
+      let readData;
+
+      beforeEach(() => {
+        memo = {
+          currentTabKey,
+        };
+
+        spyOn(localStorage, 'getItem').and.returnValue(itemValue);
+      });
+
+      describe('if .isLocalStorageAvailable is `false`', () => {
+        beforeEach(function () {
+          memo.isLocalStorageAvailable = false;
+
+          readData = global.ActiveTabMemoizer.prototype.readData.call(memo);
+        });
+
+        it('should not call .getItem and should return `null`', () => {
+          expect(localStorage.getItem).not.toHaveBeenCalled();
+          expect(readData).toBe(null);
+        });
+      });
+
+      describe('if .isLocalStorageAvailable is `true`', () => {
+        beforeEach(function () {
+          memo.isLocalStorageAvailable = true;
+
+          readData = global.ActiveTabMemoizer.prototype.readData.call(memo);
+        });
+
+        it('should call .getItem and return the localStorage value', () => {
+          expect(window.localStorage.getItem).toHaveBeenCalledWith(currentTabKey);
+          expect(readData).toBe(itemValue);
+        });
+      });
+    });
   });
 })(window);