Issue with custom helpers in Spectator v8

[matheo]

I'm submitting a...

[ ] Regression (a behavior that used to work and stopped working in a new release)
[ ] Bug report  
[ ] Performance issue
[ ] Feature request
[ ] Documentation issue or request
[x] Support request
[ ] Other... Please describe:

Context

Hi there! we do have our own set of helpers like this "find our button":

export const byButton = (text: string): DOMSelector => {
  return new DOMSelector((element: Element) => {
    const buttons = element.querySelectorAll('m-button');

    for (const button of Array.from(buttons)) {
      if (button.textContent === text) {
        return [button as HTMLElement];
      }
    }

    throw new Error(`Cannot find a button with text ${text}.`);
  });
};

After upgrade from v7 to v8

We're getting this error:

it seems that our casting to HTMLElement is not valid anymore,
but how to implement this kind of selection by tag if @testing-library doesn't support it? :(

Environment

@angular-devkit/architect       0.1202.1
@angular-devkit/build-angular   12.2.1
@angular-devkit/core            12.2.1
@angular-devkit/schematics      12.2.1
@angular/flex-layout            12.0.0-beta.34
@schematics/angular             12.2.1
rxjs                            6.6.7
typescript                      4.3.5
 
For Tooling issues:
- Node version: v14.17.3
- Platform:  Linux

[NetanelBasal]

Try asking in the @testing-library repo.

[matheo]

@NetanelBasal I asked here because DOMSelector and by* helpers are inside src/lib/dom-selectors.ts tho