Block enter if user does not type right keyword in jquery autocomplete

Question

I have used Jquery Autocomplete to build a search dropdown using the code below.

Right now, if user enters - test and if autocomplete shows

• test 123
• test 456
• test 789

and if user selects "test 123", it redirects to domain.com/test-123 which is good.

But if user just press enter after typing "test" without selecting valid result, it redirects to domain.com/>?s=test. I want to prevent that from happening.

So, even if user press enter after typing "test", user should not be redirected to another URL.

How can I block redirect if user enters a string which is not output of autocomplete?

(function( $ ) {
    $(function() {
         // Custom autocomplete instance.
        $.widget( "app.autocomplete", $.ui.autocomplete, {

            // Which class get's applied to matched text in the menu items.
            options: {
                highlightClass: "ui-state-highlight"
            },

            _renderItem: function( ul, item ) {

                // Replace the matched text with a custom span. This
                // span uses the class found in the "highlightClass" option.
                var re = new RegExp( "(" + this.term + ")", "gi" ),
                    cls = this.options.highlightClass,
                    template = "<span class='" + cls + "'>$1</span>",
                    label = item.label.replace( re, template ),
                    $li = $( "<li/>" ).appendTo( ul );

                // Create and return the custom menu item content.
                $( "<a/>" ).attr( "href", "#" )
                           .html( label )
                           .appendTo( $li );

                return $li;

            }

        });
        var autocompleteTextbox = '<div class="autocomplete-search autocomplete-search-open">'
                                    +'<a href="#" class="st-btn01 autocomplete-search-icon"><i class="search-icon" aria-hidden="true"></i></a>'
                                    +'<div class="autocomplete-search-sub1">'
                                        +'<form role="search" method="get" action="<?php echo esc_url( home_url( '+"/"+' ) ); ?>">'
                                            +'<input type="text" name="s" class="form01 autocomplete-search-input" id="autocomplete-search-input" placeholder="Type something" autocomplete="off">'
                                            +'<a href="#" class="st-btn02 autocomplete-search-icon"><i class="searchx-icon" aria-hidden="true"></i></a>'
                                        +'</form>'
                                    +'</div>'
                                +'</div>';

        var appendElement = function(){
            $('.st-navbar-collapse').append(autocompleteTextbox);
            $(this).unbind('click');
            $(".st-search .st-btn01 .search-icon").addClass('text-visibility');
        };
        $(".two-brokers").parent('a').on('click',appendElement);

        var removeElement = function(){
            $(this).parents('.autocomplete-search').remove();
            $(".two-brokers").parent('a').bind('click',appendElement);
            $(".st-search .st-btn01 .search-icon").removeClass('text-visibility');
        };
        $("body").on("click",".st-btn02.autocomplete-search-icon",removeElement);

        var searchRequest,timeoutRequest;
        $("body").on("keyup",".autocomplete-search-input",function(){
            clearTimeout(timeoutRequest);
            var _this = $(this);
            timeoutRequest = setTimeout(function(){
                // create an jq-ui autocomplete on your selected element
                _this.autocomplete({
                    minChars: 2,
                    highlightClass: "bold-text",
                    // use a function for its source, which will return ajax response
                    source: function(request, response){
                        try { searchRequest.abort(); } catch(e){}
                        // well use postautocomplete_search.ajax_url which we enqueued with WP
                        $.post(postautocomplete_search, {
                            action: 'get_test_pages',            // our action is called search
                            term: request.term           // and we get the term form jq-ui
                        }, function(data) {
                            if(!data.length){
                                var result = [{
                                    label: 'No matches found', 
                                    value: response.term
                                }];
                                response(result);
                            }else{
                               response(data);
                            }
                        }, 'json');
                    },
                    select: function( evt, ui ) { 
                        evt.preventDefault();
                        window.location = ui.item.link;
                    }
                });
            },100);
        });
    });
})( jQuery );