Running the tests doesn't check the result of the worker based pdf processing code. This should be the case.

used = horizon[k].boundary === affectedBoundary;
      }
      for (
        k = j + 1;
        !used && k < horizon.length && horizon[k].end <= affectedBoundary.y2;
        k++
      ) {
        used = horizon[k].boundary === affectedBoundary;
      }
      for (k = 0; !used && k < changedHorizon.length; k++) {
        used = changedHorizon[k].boundary === affectedBoundary;
      }
      if (!used) {
        affectedBoundary.x2New = maxXNew;
      }
    }
    Array.prototype.splice.apply(
      horizon,
      [i, j - i + 1].concat(changedHorizon)
    );
  }
  
  for (const horizonPart of horizon) {
    const affectedBoundary = horizonPart.boundary;
    if (affectedBoundary.x2New === undefined) {
      affectedBoundary.x2New = Math.max(width, affectedBoundary.x2);
    }
  }
}
class TextLayerRenderTask {