feat: expose all DOM level 2 element prototypes

[Ponynjaa]

Closes #40.

Exposes all fundamental and extended interfaces according to the specs while keeping the constructors for Node, Document, Element, Attr, CharacterData, Text, Comment, CDATASection, DocumentType, Notation, Entity, EntityReference, DocumentFragment, ProcessingInstruction private by checking a symbol in the constructor.

[Ponynjaa]

I exposed all fundamental and extended interfaces according to the specs while keeping the constructors for almost every class private (I think only DOMException, DOMImplementation, NamedNodeMap and NodeList currently don't check for the internal symbol).

I didn't add tests for the changes yet as I wanted to ask you how you want to handle this first. Do you want a new file just for testing the constructors or do you want to add a file for each class?

Also you mentioned here that you want to expose the classes under "DOM". However I think it would also be fine to just expose them directly, so you can import them like this:

import { Document, Element } from '@xmldom/xmldom';

rather than having to import them like this:

import { DOM } from '@xmldom/xmldom';
const { Document, Element } = DOM;

I think other libraries also just expose them right away, at least I know it this way.
Also I'm not sure what should be exported under "DOM" if we use this approach. I exposed everything according to the specs under DOM right now, but now there's duplicates for DOMException and DOMImplementation.

Also I forgot to apply the changes to some existing tests… I‘m gonna do that tomorrow 😅

[karfau]

Great stuff, will review it in detail later, when the tests are passing.

Since we now have an approach for private constructors, there is no need for the DOM namespace.

The public constructors that are left now are not an issue from my perspective.

Regarding tests: I think I would prefer to have a check for each "class" in the related file. Can even be the first test in each file.

Is the symbol is even private for "us", meaning we don't even have access to it in the tests and have to use the DOMImplementation to create them?
I guess that makes the most sense, right?
Update: just checked your implementation: By moving the symbol to lib/dom.js we wouldn't need to export it at all, right? Of course that has some implications on tests, but it also means nobody can do
import {INTERNAL_SYMBOL} from " @xmldom/xmldom/lib/conventions".
What do you think?

A last remark: whatever is in the PR description usually goes into the commit message when squash merging. So we should avoid quwstions and instead describe the reasoning behind the changes. Questions can best be put in the comments. Would be nice if you can change that. Thx

PS: you don't need to mention me, I'm watching the repo for every change.

[Ponynjaa]

Hey @karfau,
I implemented your suggestions and wanted to start with implementing the tests. I rewrote the existing tests to use document.createXXX for the creation of the different Nodes. This seems to work fine, those tests pass. However almost all of the tests who expect some kind of Exception fail... I don't see the problem, maybe you can have a look at it?

[codecov]

Codecov Report

Attention: Patch coverage is 98.73418% with 1 lines in your changes are missing coverage. Please review.

❗ No coverage uploaded for pull request base (master@8f206f7). Click here to learn what that means.

Files	Patch %	Lines
lib/dom.js	98.18%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff            @@
##             master     #637   +/-   ##
=========================================
  Coverage          ?   94.27%           
=========================================
  Files             ?        8           
  Lines             ?     2096           
  Branches          ?      537           
=========================================
  Hits              ?     1976           
  Misses            ?      120           
  Partials          ?        0           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[karfau]

Thx