[FSSDK-10880] new tests addition

src/Provider.spec.tsx

@@ -107,6 +107,21 @@ describe('OptimizelyProvider', () => {
     });
   });
 
+  it('should succeed with the initial user available in client', () => {
+    render(<OptimizelyProvider optimizely={mockReactClient} />);
+
+    expect(mockReactClient.setUser).toHaveBeenCalledWith(user1);
+  });
+
+  it('should succeed with the initial user id and newly passed attributes', () => {
+    render(<OptimizelyProvider optimizely={mockReactClient} userAttributes={{ attr1: 'value2' }} />);
+
+    expect(mockReactClient.setUser).toHaveBeenCalledWith({
+      id: user1.id,
+      attributes: { attr1: 'value2' },
+    });
+  });
+
   it('should not update when isServerSide is true', () => {
     // Initial render
     const { rerender } = render(<OptimizelyProvider optimizely={mockReactClient} isServerSide={true} user={user1} />);