webpack4, form-item data check error:
asyncValidator2.default is not a constructor.

after debugging, it is found that asyncValidator2.default.default is the required constructor.

read the source code:
may be a problem with this sentence in the form-item.vue file:

    const validator = new AsyncValidator(descriptor);

may need to be changed to (not sure):

    const validator = new AsyncValidator.default(descriptor);