fix(toast): isVisible property binding - master

[dobromirts]

Closes #8207

Additional information (check all that apply):

• Bug fix
• New functionality
• Documentation
• Demos
• CI/CD

Checklist:

• All relevant tags have been applied to this PR
• This PR includes unit tests covering all the new code (test guidelines)
• This PR includes API docs for newly added methods/properties (api docs guidelines)
• This PR includes feature/README.MD updates for the feature docs
• This PR includes general feature table updates in the root README.MD
• This PR includes CHANGELOG.MD updates for newly added functionality
• This PR contains breaking changes
• This PR includes ng update migrations for the breaking changes (migrations guidelines)
• This PR includes behavioral changes and the feature specification has been updated with them

[hanastasov]

Please add a test that verifies setting isVisible actually opens/shows the toast.

[hanastasov]

Using event handlers for executing expectations results in false negative test - if event handlers are not called, test will still succeed, while there is a bug (toast is not actually opened and event is not emitted).
It's better to use jasmine spyOn to test if event is emitted.

Also, after discussion, we agreed for the following enhacements:

1. Rethinkg igxToggleDircetive open method:

        this.collapsed = false;
        this.cdr.detectChanges();

 

        const openEventArgs: ToggleViewCancelableEventArgs = { cancel: false, owner: this, id: this._overlayId };
        this.onOpening.emit(openEventArgs);
        if (openEventArgs.cancel) {
            this.collapsed = true;
            this.cdr.detectChanges();
            return;
        }

Seems too much. Must be safe to emit the onOpening event first, and if canceled, then return. Everything else to be removed.

2. Rethink if this.unsubscribe() is needed
   All those subscriptions (_overlayAppendedSub, _overlayOpenedSub, _overlayClosingSub, _overlayClosedSub) can be refactored to take the first emitted value only:

        this._overlayOpenedSub = this.overlayService.onOpened.pipe(...this._overlaySubFilter, first())...

3. Rethink if safe to move all subscriptions (_overlayAppendedSub, _overlayOpenedSub, _overlayClosingSub, _overlayClosedSub) in the constructor. Make sure _overlayId is correct.

4. See if any detectChanges() call is excessive.Try to move all of those in the overlay.

5. Deprecate toast showing and hiding events, as suggested in the issue.

[zdrawku]

Well done. I see that the changes regarding the migration are applied as well.

[hanastasov]

1. visibility is updated by the toggle() method
2. should open and close toast when set values to isVisible
3. should emit onHidden when toggle onClosed is fired
4. should emit onShown when toggle onOpened is fired

The above tests implementation result in false negative tests. Please refactor those.