toHaveCssClass custom matcher for jest-dom

toHaveClass.js

expect.extend({
  toHaveCssClass(received, cssClass) {
    const pass = received.querySelector(`.${cssClass}`) !== undefined;
    
    return {
      message: () => this.isNot ? `${cssClass} was found` : `${cssClass} not found`,
      pass: pass
    };
  }
});