woocommerce-spinners.js

/**
 * WooCommerce Quanity buttons add-back
 */
jQuery( function( $ ) {
    var $testProp = $( 'div.quantity:not(.buttons_added), td.quantity:not(.buttons_added)' ).find('qty');
    if ($testProp && $testProp.prop('type') != 'date') {
        // Quantity buttons
        $( 'div.quantity:not(.buttons_added), td.quantity:not(.buttons_added)' ).addClass( 'buttons_added' ).append( '<input type="button" value="+" class="plus" />' ).prepend( '<input type="button" value="-" class="minus" />' );

        // Target quantity inputs on product pages
        $( 'input.qty:not(.product-quantity input.qty)' ).each( function() {

            var min = parseFloat( $( this ).attr( 'min' ) );

            if ( min && min > 0 && parseFloat( $( this ).val() ) < min ) {
                $( this ).val( min );
            }
        });

        $( document ).on( 'click', '.plus, .minus', function() {

            // Get values
            var $qty		= $( this ).closest( '.quantity' ).find( '.qty' ),
                currentVal	= parseFloat( $qty.val() ),
                max			= parseFloat( $qty.attr( 'max' ) ),
                min			= parseFloat( $qty.attr( 'min' ) ),
                step		= $qty.attr( 'step' );

            // Format values
            if ( ! currentVal || currentVal === '' || currentVal === 'NaN' ) currentVal = 0;
            if ( max === '' || max === 'NaN' ) max = '';
            if ( min === '' || min === 'NaN' ) min = 0;
            if ( step === 'any' || step === '' || step === undefined || parseFloat( step ) === 'NaN' ) step = 1;

            // Change the value
            if ( $( this ).is( '.plus' ) ) {

                if ( max && ( max == currentVal || currentVal > max ) ) {
                    $qty.val( max );
                } else {
                    $qty.val( currentVal + parseFloat( step ) );
                }

            } else {

                if ( min && ( min == currentVal || currentVal < min ) ) {
                    $qty.val( min );
                } else if ( currentVal > 0 ) {
                    $qty.val( currentVal - parseFloat( step ) );
                }

            }

            // Trigger change event
            $qty.trigger( 'change' );
        });
    }
});

Thanks man this one was wracking my brain, the functionality looks to be removed in the latest version of woocommerce