Magento2: dynamic-rows / dynamic-rows-grid components are missing prototype / legacy dependency

[netzkollektiv]

Preconditions

1. Magento 2.1.8
2. server side irrelevant for issue

Steps to reproduce

1. Implement a dynamic rows component in a page where prototype (legacy-build.min.js) is not defined as dependecy
2. Try to use it
3. When saving the listing grid, the dynamic rows component throws an error (max.each is not a function)

Expected result

1. The item from the listing should show up in the dynamic rows grid

Actual result

1. max.each is not a function
2. There is no row being added to the dynamic rows grid
   

Code excerpt

At least this function in Magento_Ui/js/dynamic-rows/dynamic-rows-grid.js needs prototypejs:

        /**
         * Check changed records
         *
         * @param {Array} data - array with records data
         * @returns {Array} Changed records
         */
        _checkGridData: function (data) {
            var cacheLength = this.cacheGridData.length,
                curData = data.length,
                max = cacheLength > curData ? this.cacheGridData : data,
                changes = [],
                obj = {};

            max.each(function (record, index) {
                obj[this.map[this.identificationDRProperty]] = record[this.map[this.identificationDRProperty]];

                if (!_.where(this.cacheGridData, obj).length) {
                    changes.push(data[index]);
                }
            }, this);

            return changes;
        }

Workaround

Add a requirejs-config.js to your module which defines prototype as dependency:

var config = {
    shim: {
        'Magento_Ui/js/dynamic-rows/dynamic-rows-grid': {
            deps: ['prototype']
        }
        'Magento_Ui/js/dynamic-rows/dynamic-rows': {
            deps: ['prototype']
        }
    }
};

Solution

Add protoype as dependency to Magento_Ui/js/dynamic-rows/dynamic-rows.js:

define([
    'ko',
    'mageUtils',
    'underscore',
    'uiLayout',
    'uiCollection',
    'uiRegistry',
    'mage/translate',
    'prototype'
], function (ko, utils, _, layout, uiCollection, registry, $t) {
    'use strict';

    return uiCollection.extend({
        defaults: {
            defaultRecord: false,
            columnsHeader: true,
            columnsHeaderAfterRender: false,
            columnsHeaderClasses: '',
            labels: [],

Real solution

Remove prototype legacy stuff completely.
This took me frustratingly long to discover.
see also http://alanstorm.com/magento-2-prototypejs-still-lurks/

[magento-engcom-team]

@netzkollektiv , thank you for your report.
From your steps to reproduce we cannot completely understand how to reproduce issue. Please, give us your code source to reproduce this issue.

[magento-engcom-team]

@netzkollektiv, we are closing this issue due to inactivity. If you'd like to update it, please reopen the issue.

[netzkollektiv]

Is this issue fixed? If not, why did you close it?

The steps are clear & easy to follow.
Even without reproducing this should be clear for a developer.

[tschirmer]

Was this ever fixed?

[netzkollektiv]

@tschirmer
They now use max.forEach instead of max.each, so I believe it is fixed.
But I did not have time yet to look back into it.