magento 2: trigger js form validation without submit

was able to figure this out by referencing:

module-checkout-agreements/view/frontend/web/js/model/agreement-validator.js

After including mage/validation you have to pass argument isValid to mage.validation in order to invoke the validation

Full code looks like

require([
    'jquery',
    'mage/validation'
], function($){

    var dataForm = $('#form-validate');
    var ignore = null;

    dataForm.mage('validation', {
        ignore: ignore ? ':hidden:not(' + ignore + ')' : ':hidden'
    }).find('input:text').attr('autocomplete', 'off');

    $('button#my-button').click( function() { //can be replaced with any event
        dataForm.validation('isValid'); //validates form and returns boolean
    });
});

You can also replace argument with clearError to remove validation error messages

You can try this:

require(["jquery"], function ($) {
    $(document).ready(function () {
        $('#my-button-name').click(function () { // The button type should be "button" and not submit
            if ($('#form-name').valid()) {
                alert("Validation pass");
                return false;
            }else{
                alert("Validation failed");
                return false;
            }
        });
    });
});

Hope this may help you!