import { getErrorMessage } from './getErrorMessage';

describe('getErrorMessage', () => {
  it('returns the error message when the error is an instance of Error class', () => {
    const error = new Error('An error occurred');
    expect(getErrorMessage(error)).toEqual('An error occurred');
  });

  it('converts non-Error values to string', () => {
    expect(getErrorMessage('Some error message')).toEqual('Some error message');
    expect(getErrorMessage(null)).toEqual('null');
    expect(getErrorMessage(undefined)).toEqual('undefined');
    expect(getErrorMessage(123)).toEqual('123');
    expect(getErrorMessage(true)).toEqual('true');
  });
});