Some emitted code results in reduced coverage reports (see #13029, or example below).

To combat this, it would be nice to have a feature similar to the auxiliaryCommentBefore in Babel, which adds a comment of choice before all non-user injected code.

When set, say with Istanbul, to 'istanbul ignore next', such auxiliary transpiled code will not be part of the coverage report.

Example

This:

constructor( x: number, y: number, w: number, h: number ) {
    super(); // <- 'Branch not covered'.
    this.rect = new Rect( x, y, w, h);
}

transpiles to this:

var _this = _super.call(this) || this; // <- || this is not covered. Why would it?