I started using Jasmine. I want to test a validation function but I don't know how to do it.

I wrote the first case. How can I get a message in the event of an error?

Any help will be important to me.

describe('First test, function() {  
 it('First case', function() {
  expect({login: 'first_user'}).toEqual({login: jasmine.stringMatching(/^[A-Za-z-ĘÓŁŚĄŻŹĆŃęółśążźćń0-9.\-_ /]+$/)});
  expect({haslo: 'FirstUser!1'}).toEqual({haslo: jasmine.stringMatching(/^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)(?=.*[@$!%*?&])[A-Za-z\d@$!%*?&]{8,}$/)});
 })
})