demo.js

const demo = {
  authorize() {
    const pushError = (messages) => this.push({
      type: nTypes.ERROR, messages, action: nActionTypes.CLOSE
    });

    this.$validator.validateAll('auth')
      .then(success => {
        if (!success) return pushError([{ message: obj.errors.all().join('<br>') }]);
        const { email, password } = this;
        this.login({ email, password }).catch(error => pushError(Object.keys(error.response.data).map(key => ({
          header: `${key.charAt(0).toUpperCase() + key.slice(1)}`,
          message: error.response.data[key].join(' ')
        }))));
      });
  }
}