How to test MatDialogRef overlayref

Question

How to test dialogref from MatDialogRef?

dialogRef: MatDialogRef<testComponent>;

    showBackdrop() {
     const backdrop = this.dialogRef['_ref'].overlayRef._backdropElement.style.display = 'block'
    }

Answer 1

const matDialogRefMock = {
        _ref : {
            overlayRef: {
                _backdropElement: {
                    style: {
                        display: 'block'
                    }
                }
            },
        }
    };