Added ariaContainerElement to IStandaloneEditorConstructionOptions

[crackalak]

This PR fixes issues with ARIA when using the standalone editor in shadow DOM: microsoft/monaco-editor#619

[ghost]

All CLA requirements met.

[crackalak]

To test, run monaco editor shadow dom test: microsoft/monaco-editor#2644

[simonh1000]

I'm trying to take advanatge of this change. My package.json has "monaco-editor": "^0.28.1" which seems to be the latest, but does not have this - oh so welcome - commit. Any advice?

[crackalak]

@simonh1000 this change hasn't been released yet, it's part of the September 2021 milestone, so you'll have to join me in waiting!

[simonh1000]

Seems to work except for

[alexdima]

@simonh1000 What is the problem? I'm not sure I understand from the screenshot. The property ariaContainerElement appears to be defined in the IStandaloneEditorConstructionOptions interface in the .d.ts that we ship.

[simonh1000]

document.querySelector returns an Element but the typings require an HTMLElement. As a result I get a typescript error, although the code itself seems to work as expected

[alexdima]

The typing we ship is correct. We expect an HTMLElement to be passed in.

[simonh1000]

For anyone coming later, one way around the typescript error is

        let mbDomNode = document.querySelector("#code-area");
        let codeArea = mbDomNode ? (mbDomNode as HTMLElement) : undefined;

[crackalak]

@simonh1000 querySelector accepts a type argument:
const codeArea = document.querySelector<HTMLElement>("#code-area");