diff -r 1f340f3597a8 -r ea92f4fe783d client/src/selectors/__tests__/syncSelectors.test.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/client/src/selectors/__tests__/syncSelectors.test.js	Mon Oct 08 18:35:47 2018 +0200
@@ -0,0 +1,186 @@
+import {
+  getLastSync,
+  isSynchronizing,
+  isSynchronized
+} from '../syncSelectors';
+
+import { ActionEnum } from '../../constants';
+
+describe('Sync selector test', () => {
+
+  test('getLastSync', ()  => {
+    const inputState = {
+      status: {
+        isSynchronizing: false,
+        online: false
+      },
+      authStatus: {
+        token: '',
+        isAuthenticated: false,
+        clientId: null,
+        lastSync: 110,
+        currentUser: null,
+        currentGroup: null
+      },
+    };
+
+    expect(getLastSync(inputState)).toBe(110);
+  });
+
+  test('getLastSyncAbsent', ()  => {
+    const inputState = {
+      status: {
+        isSynchronizing: false,
+        online: false
+      },
+      authStatus: {
+        token: '',
+        isAuthenticated: false,
+        clientId: null,
+        currentUser: null,
+        currentGroup: null
+      },
+    };
+
+    expect(getLastSync(inputState)).toBe(0);
+  });
+
+
+  test('getLastSyncAuthStatusAbsent', ()  => {
+    const inputState = {
+      status: {
+        isSynchronizing: false,
+        online: false
+      },
+    };
+
+    expect(getLastSync(inputState)).toBe(0);
+  });
+
+  test('isSynchronizingFalse', ()  => {
+    const inputState = {
+      status: {
+        isSynchronizing: false,
+        online: false
+      },
+      authStatus: {
+        token: '',
+        isAuthenticated: false,
+        clientId: null,
+        lastSync: 110,
+        currentUser: null,
+        currentGroup: null
+      },
+    };
+
+    expect(isSynchronizing(inputState)).toBe(false);
+  });
+
+
+  test('isSynchronizingTrue', ()  => {
+    const inputState = {
+      status: {
+        isSynchronizing: true,
+        online: false
+      },
+      authStatus: {
+        token: '',
+        isAuthenticated: false,
+        clientId: null,
+        lastSync: 110,
+        currentUser: null,
+        currentGroup: null
+      },
+    };
+
+    expect(isSynchronizing(inputState)).toBe(true);
+  });
+
+  test('isSynchronizedEmpty', ()  => {
+    const inputState = {
+      status: {
+        isSynchronizing: true,
+        online: false
+      },
+      authStatus: {
+        token: '',
+        isAuthenticated: false,
+        clientId: null,
+        lastSync: 110,
+        currentUser: null,
+        currentGroup: null
+      },
+      notes: [],
+      sessions: []
+    };
+
+    expect(isSynchronized(inputState)).toBe(true);
+  });
+
+
+  test('isSynchronizedOk', ()  => {
+    const inputState = {
+      status: {
+        isSynchronizing: true,
+        online: false
+      },
+      authStatus: {
+        token: '',
+        isAuthenticated: false,
+        clientId: null,
+        lastSync: 110,
+        currentUser: null,
+        currentGroup: null
+      },
+      notes: [ { title: 'note1', action: ActionEnum.NONE }, { title: 'note2', action: ActionEnum.NONE }, { title: 'note3', action: ActionEnum.NONE } ],
+      sessions: [ { title: 'session1', action: ActionEnum.NONE }, { title: 'session2', action: ActionEnum.NONE }, { title: 'session3', action: ActionEnum.NONE } ]
+    };
+
+    expect(isSynchronized(inputState)).toBe(true);
+  });
+
+
+  test('isSynchronizedKo', ()  => {
+    const inputState = {
+      status: {
+        isSynchronizing: true,
+        online: false
+      },
+      authStatus: {
+        token: '',
+        isAuthenticated: false,
+        clientId: null,
+        lastSync: 110,
+        currentUser: null,
+        currentGroup: null
+      },
+      notes: [ { title: 'note1', action: ActionEnum.NONE }, { title: 'note2', action: ActionEnum.UPDATED }, { title: 'note3', action: ActionEnum.NONE } ],
+      sessions: [ { title: 'session1', action: ActionEnum.NONE }, { title: 'session2', action: ActionEnum.DELETED }, { title: 'session3', action: ActionEnum.NONE } ]
+    };
+
+    expect(isSynchronized(inputState)).toBe(false);
+  });
+
+
+  test('isSynchronizedJustOne', ()  => {
+    const inputState = {
+      status: {
+        isSynchronizing: true,
+        online: false
+      },
+      authStatus: {
+        token: '',
+        isAuthenticated: false,
+        clientId: null,
+        lastSync: 110,
+        currentUser: null,
+        currentGroup: null
+      },
+      notes: [ { title: 'note1', action: ActionEnum.NONE }, { title: 'note2', action: ActionEnum.UPDATED }, { title: 'note3', action: ActionEnum.NONE } ],
+      sessions: [ { title: 'session1', action: ActionEnum.NONE }, { title: 'session2', action: ActionEnum.NONE }, { title: 'session3', action: ActionEnum.NONE } ]
+    };
+
+    expect(isSynchronized(inputState)).toBe(false);
+  });
+
+})