Override js widget variable using mixin

I’m trying to override a widget variable using mixin , but I get the following error Uncaught TypeError: target.extend is not a function

the original file is

define([
"underscore",
"jquery",
"knockout",
'amShopbyTopFilters',
"productListToolbarForm",
"amShopbyFilterAbstract",
"Magento_PageCache/js/page-cache"
], function (_, $, ko, amShopbyTopFilters) {
'use strict';
$.widget('mage.amShopbyAjax', {
prevCall: false,
$shopbyOverlay: null,
cached: [],
memorizeData: [],
blockToolbarProcessing: false,
swatchesTooltip: '.swatch-option-tooltip',
filterTooltip: '.amshopby-filter-tooltip',
response: null,
cacheKey: null,
startAjax: false,
isCategorySingleSelect: 0,
nodes: {
loader: $('<div id="amasty-shopby-overlay" class="amshopby-overlay-block">' +
'<span class="amshopby-loader"></span></div>')
},
selectors: {
products_wrapper: '#amasty-shopby-product-list, .search.results',
top_nav: '.amasty-catalog-topnav',
products: '.products.wrapper',
overlay: '#amasty-shopby-overlay',
top_navigation: '.catalog-topnav .block.filter',
js_init: '[data-am-js="js-init"]',
title_head: '#page-title-heading'
},
_create: function () {
var self = this;
$(function () {
self.initWidget();
if (typeof window.history.replaceState === "function") {
window.history.replaceState({url: document.URL}, document.title);
setTimeout(function () {
/*
Timeout is a workaround for iPhone
Reproduce scenario is following:
1. Open category
2. Use pagination
3. Click on product
4. Press "Back"
Result: Ajax loads the same content right after regular page load
*/
window.onpopstate = function (e) {
if (e.state) {
if ($.mage.amShopbyApplyFilters) {
$.mage.amShopbyApplyFilters.prototype.showButtonClick = true;
}
self.callAjax(e.state.url, []);
self.$shopbyOverlay.show();
}
};
}, 0)
}
});
},
initWidget: function () {
var self = this,
swatchesTooltip = $(self.swatchesTooltip),
filterTooltip = $(self.filterTooltip);
$(document).on('baseCategory', function (event, eventData) {
self.currentCategoryId = eventData;
});
$(document).on('amshopby:submit_filters', function (event, eventData) {
var data = eventData.data,
clearUrl = self.options.clearUrl,
isSorting = eventData.isSorting,
pushState = !self.options.submitByClick;
if (typeof data.clearUrl !== 'undefined') {
clearUrl = data.clearUrl;
delete data.clearUrl;
}
if (self.prevCall) {
self.prevCall.abort();
}
var dataAndUrl = data.slice(0);
dataAndUrl.push(clearUrl ? clearUrl : self.options.clearUrl);
var cacheKey = JSON.stringify(dataAndUrl);
$.mage.amShopbyAjax.prototype.cacheKey = cacheKey;
if (self.cached[cacheKey]) {
var response = self.cached[cacheKey];
if (pushState || isSorting) {
if (response.newClearUrl
&& response.newClearUrl.indexOf('?p=') == -1
&& response.newClearUrl.indexOf('&p=') == -1
) {
self.options.clearUrl = response.newClearUrl;
}
window.history.pushState({url: response.url}, '', response.url);
self.reloadHtml(response);
self.initAjax();
} else if ($.mage.amShopbyApplyFilters) {
$.mage.amShopbyApplyFilters.prototype.showButtonCounter(
response.productsCount
);
}
return;
}
self.prevCall = self.callAjax(clearUrl, data, pushState, cacheKey, isSorting);
});
$(document).on('touchstart touchmove scroll', function () {
if (swatchesTooltip) {
swatchesTooltip.hide();
filterTooltip.trigger('mouseleave');
}
});
$(document).on('amshopby:reload_html', function (event, eventData) {
self.reloadHtml(eventData.response);
});
filterTooltip.on('tap', function () {
$(this).trigger('mouseenter');
});
self.initAjax();
},
callAjax: function (clearUrl, data, pushState, cacheKey, isSorting) {
var self = this;
if (pushState || isSorting) {
this.$shopbyOverlay.show();
}
data.every(function (item, key) {
if (item.name.indexOf('[cat]') != -1) {
if (item.value == self.options.currentCategoryId) {
data.splice(key, 1);
} else {
item.value.split(',').filter(function (element) {
return element != self.options.currentCategoryId
}).join(',');
}
return false;
}
return true;
});
data.push({name: 'shopbyAjax', value: 1});
data = this.addMemorizeData(data);
$.mage.amShopbyAjax.prototype.startAjax = true;
if (!clearUrl) {
clearUrl = self.options.clearUrl;
}
clearUrl = clearUrl.replace(/amp;/g, '');
self.clearUrl = clearUrl;
return $.ajax({
url: clearUrl,
data: data,
cache: true,
success: function (response) {
try {
$.mage.amShopbyAjax.prototype.startAjax = false;
response = JSON.parse(response);
if (response.isDisplayModePage) {
throw new Error();
}
if (cacheKey) {
self.cached[cacheKey] = response;
}
$.mage.amShopbyAjax.prototype.response = response;
if (response.newClearUrl
&& (response.newClearUrl.indexOf('?p=') == -1 && response.newClearUrl.indexOf('&p=') == -1)) {
self.options.clearUrl = response.newClearUrl;
}
if (pushState || ($.mage.amShopbyApplyFilters && $.mage.amShopbyApplyFilters.prototype.showButtonClick) || isSorting) {
window.history.pushState({url: response.url}, '', response.url);
}
if (self.options.submitByClick !== 1 || isSorting) {
self.reloadHtml(response);
}
if ($.mage.amShopbyApplyFilters && $.mage.amShopbyApplyFilters.prototype.showButtonClick) {
$.mage.amShopbyApplyFilters.prototype.showButtonClick = false;
$.mage.amShopbyAjax.prototype.response = false;
self.reloadHtml(response);
}
if ($.mage.amShopbyApplyFilters) {
$.mage.amShopbyApplyFilters.prototype.showButtonCounter(response.productsCount);
}
$(document).trigger('amshopby:ajax_filter_applied');
} catch (e) {
var url = self.clearUrl ? self.clearUrl : self.options.clearUrl;
window.location = (this.url.indexOf('shopbyAjax') == -1) ? this.url : url;
}
},
error: function (response) {
try {
if (response.getAllResponseHeaders() != '') {
self.options.clearUrl ? window.location = self.options.clearUrl : location.reload();
}
} catch (e) {
window.location = (this.url.indexOf('shopbyAjax') == -1) ? this.url : self.options.clearUrl;
}
},
always: function () {
if (self.$shopbyOverlay) {
self.$shopbyOverlay.hide();
}
}
});
},
addMemorizeData: function (data) {
if (this.memorizeData) {
$.each(this.memorizeData, function (key, param) {
var current = this.filterDataByProp(data, param, 'name');
if (_.isUndefined(current)) {
data.push({ name: param.name, value: param.value });
} else {
current.value = param.value;
}
}.bind(this));
}
return data;
},
filterDataByProp: function (data, param, prop) {
return data.find(function (obj) {
return obj[prop] === param[prop];
});
},
reloadHtml: function (data) {
var selectSidebarNavigation = '.sidebar.sidebar-main .block.filter',
selectTopNavigation = selectSidebarNavigation + '.amshopby-all-top-filters-append-left',
selectMainNavigation = '',
$productsWrapper = this.getProductBlock();
this.options.currentCategoryId = data.currentCategoryId
? data.currentCategoryId
: this.options.currentCategoryId;
if ($(selectTopNavigation).first().length > 0) {
selectMainNavigation = selectTopNavigation; //if all filters are top
} else if ($(selectSidebarNavigation).first().length > 0) {
selectMainNavigation = selectSidebarNavigation;
}
$('.am_shopby_apply_filters').remove();
if (!selectMainNavigation) {
if ($('.sidebar.sidebar-main').first().length) {
$('.sidebar.sidebar-main').first().prepend("<div class='block filter'></div>");
selectMainNavigation = selectSidebarNavigation;
} else {
selectMainNavigation = '.block.filter';
}
}
$(selectMainNavigation).first().replaceWith(data.navigation);
$(selectMainNavigation).first().trigger('contentUpdated');
//top nav already exist into categoryProducts
if (!data.categoryProducts || data.categoryProducts.indexOf('amasty-catalog-topnav') == -1) {
$(this.selectors.top_navigation).first().replaceWith(data.navigationTop);
$(this.selectors.top_navigation).first().trigger('contentUpdated');
}
var mainContent  = data.categoryProducts || data.cmsPageData;
if (mainContent) {
$productsWrapper.replaceWith(mainContent);
// we should reinitialize element - because it was replaced and removed
$productsWrapper = this.getProductBlock();
try {
if (typeof $.fn.applyBindings !== 'undefined') {
ko.cleanNode($productsWrapper)
$productsWrapper.applyBindings();
}
$productsWrapper.trigger('contentUpdated');
} catch (e) {
//do nothing. error with third party extension
}
}
$(this.selectors.title_head).closest('.page-title-wrapper').replaceWith(data.h1);
$(this.selectors.title_head).trigger('contentUpdated');
this.replaceBlock('.breadcrumbs', 'breadcrumbs', data);
this.replaceBlock('.switcher-currency', 'currency', data);
this.replaceBlock('.switcher-language', 'store', data);
this.replaceBlock('.switcher-store', 'store_switcher', data);
this.replaceCategoryView(data);
if (data.behaviour) {
this.updateMultipleWishlist(data.behaviour);
}
$(window).trigger('google-tag');
mediaCheck({
media: '(max-width: 768px)',
entry: function () {
amShopbyTopFilters.moveTopFiltersToSidebar();
if (selectMainNavigation == selectTopNavigation
&& $(selectSidebarNavigation + ':not(.amshopby-all-top-filters-append-left)').length != 0) {
$(selectSidebarNavigation).first().remove();
}
},
exit: function () {
amShopbyTopFilters.removeTopFiltersFromSidebar();
}
});
var swatchesTooltip = $('.swatch-option-tooltip');
if (swatchesTooltip.length) {
swatchesTooltip.hide();
}
if (this.$shopbyOverlay) {
this.$shopbyOverlay.hide();
}
var productList = $(this.selectors.products_wrapper).last();
this.scrollUp();
$('.amshopby-filters-bottom-cms').remove();
productList.append(data.bottomCmsBlock);
$(this.selectors.js_init).first().replaceWith(data.js_init);
$(this.selectors.js_init).first().trigger('contentUpdated');
this.afterChangeContentExternal(productList);
this.initAjax();
},
/**
* @public
* @return {Object}
*/
getProductBlock: function () {
var $productsWrapper = $(this.selectors.products_wrapper).last();
if ($productsWrapper.parent('.search.results').length) {
$productsWrapper = $productsWrapper.parent('.search.results');
}
return $productsWrapper;
},
scrollUp: function () {
var productList = $(this.selectors.products_wrapper).last(),
topNavBlock = $(this.selectors.top_nav);
if (this.options.scrollUp && productList.length) {
$(document).scrollTop(this.options.scrollUp === 1
? (topNavBlock.length ? topNavBlock.offset().top : productList.offset().top)
: 0);
}
},
afterChangeContentExternal: function (productList) {
//compatibility with Amasty Scroll extension
$(document).trigger('amscroll_refresh');
//fix issue with wrong form key
productList.formKey();
//porto theme compatibility
var lazyImg = $("img.porto-lazyload:not(.porto-lazyload-loaded)");
if (lazyImg.length && typeof $.fn.lazyload == 'function') {
lazyImg.lazyload({effect:"fadeIn"});
}
if ($('head').html().indexOf('Infortis') > -1) {
$(document).trigger('last-swatch-found');
}
},
updateMultipleWishlist: function (data) {
$('#popup-tmpl').remove();
$('#split-btn-tmpl').remove();
$('#form-tmpl-multiple').replaceWith(data);
$('body').off('click', '[data-post-new-wishlist]');
require('uiRegistry').remove('multipleWishlist');
$('.page-wrapper').trigger('contentUpdated');
},
replaceBlock: function (blockClass, dataName, data) {
$(blockClass).replaceWith(data[dataName]);
$(blockClass).trigger('contentUpdated');
},
replaceCategoryView: function (data) {
var imageElement = $(".category-image"),
descrElement = $(".category-description");
if (data.image) {
if (imageElement.length !== 0) {
imageElement.replaceWith(data.image);
} else {
imageElement.prependTo("column.main");
}
} else {
imageElement.remove();
}
if (data.description) {
if (descrElement.length !== 0) {
descrElement.replaceWith(data.description);
} else {
if (imageElement.length !== 0) {
$(data.description).insertAfter(imageElement.selector);
} else {
descrElement.prependTo("column.main");
}
}
} else {
descrElement.remove();
}
$('title').html(data.title);
if (data.categoryData) {
var categoryViewSelector = ".category-view";
if ($(categoryViewSelector).length === 0) {
$('<div class="category-view"></div>').insertAfter('.page.messages');
}
$(categoryViewSelector).replaceWith(data.categoryData);
}
},
generateOverlayElement: function () {
var selectors = this.selectors,
productListContainer = $(selectors.products_wrapper
.replace(',', ' ' + selectors.products + ',') + ' ' + selectors.products);
if (!$(this.selectors.overlay).length) {
productListContainer.append(this.nodes.loader);
}
this.$shopbyOverlay = $(this.selectors.overlay);
},
initAjax: function () {
var self = this;
this.generateOverlayElement();
if ($.mage.productListToolbarForm) {
//change page limit
$.mage.productListToolbarForm.prototype.changeUrl = function (paramName, paramValue, defaultValue) {
// Workaround to prevent double method call
if (self.blockToolbarProcessing) {
return;
}
self.blockToolbarProcessing = true;
setTimeout(function () {
self.blockToolbarProcessing = false;
}, 300);
var decode = window.decodeURIComponent,
urlPaths = this.options.url.split('?'),
urlParams = urlPaths[1] ? urlPaths[1].split('&') : [],
paramData = {},
currentPage = this.getCurrentPage ? this.getCurrentPage() : '1',
newPage;
for (var i = 0; i < urlParams.length; i++) {
var parameters = urlParams[i].split('=');
paramData[decode(parameters[0])] = parameters[1] !== undefined
? decode(parameters[1].replace(/+/g, '%20'))
: '';
}
if (currentPage > 1 && paramName === this.options.limit) {
newPage = Math.floor(this.getCurrentLimit() * (currentPage - 1) / paramValue) + 1;
if (newPage > 1) {
paramData[this.options.page] = newPage;
} else {
delete paramData[this.options.page];
}
}
paramData[paramName] = paramValue;
if (paramValue == defaultValue) {
delete paramData[paramName];
}
if (self.options.isMemorizerAllowed) {
self.memorizeData.push({name: paramName, value: paramValue});
}
self.options.clearUrl = self.getNewClearUrl(
paramName,
paramData[paramName] ? paramData[paramName] : '',
paramData[this.options.page]
);
//add ajax call
$.mage.amShopbyFilterAbstract.prototype.prepareTriggerAjax(null, null, null, true);
};
}
//change page number
$(".toolbar .pages a").unbind('click').bind('click', function (e) {
var newUrl = $(this).prop('href'),
updatedUrl = null,
urlPaths = newUrl.split('?'),
urlParams = urlPaths[1] ? urlPaths[1].split('&') : [];
for (var i = 0; i < urlParams.length; i++) {
if (urlParams[i].indexOf("p=") === 0) {
var pageParam = urlParams[i].split('=');
updatedUrl = self.getNewClearUrl(pageParam[0], pageParam[1] > 1 ? pageParam[1] : '');
break;
}
}
if (!updatedUrl) {
updatedUrl = this.href;
}
updatedUrl = updatedUrl.replace('amp;', '');
$.mage.amShopbyFilterAbstract.prototype.prepareTriggerAjax(document, updatedUrl, false, true);
$(document).scrollTop($(self.selectors.products_wrapper).offset().top);
e.stopPropagation();
e.preventDefault();
});
},
//Update url after change page size or current page.
getNewClearUrl: function (key, value, page) {
var url = new URL(window.location.href),
params = new window.URLSearchParams(url.search);
if (value !== '') {
params.set(key, value);
} else {
params.delete(key);
}
if (page) {
params.set('p', page);
} else if (key !== 'p') {
params.delete('p');
}
url.search = params;
return window.decodeURIComponent(url.toString());
}
});
return $.mage.amShopbyAjax;
});

my mixin file is

define([
"underscore",
"jquery",
"knockout",
'amShopbyTopFilters',
"productListToolbarForm",
"amShopbyFilterAbstract",
"Magento_PageCache/js/page-cache"
], function (_, $, ko, amShopbyTopFilters) {
'use strict';
var loaderUrl = $("#loaderUrl").val();
return function (target) {
target.nodes.loader = $('<div id="amasty-shopby-overlay" class="amshopby-overlay-block">' +
'<img src="'+loaderUrl+'" alt="Loading..."></div>');
}
});