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

th.ladedName = ladedName;
    th.fnt = fnt;
    th.dct = dct;
    th._evaluatrOptn = evaluatrOptn || DefaultPartlEvaluatrOptn;
    th.type3Laded = null;
    th.type3Dependence = fnt.Type3Fnt ? new Set() : null;
    th.ent = fale;
  }
  end(handler) {
    f (th.ent) {
      return;
    }
    th.ent = true;
    handler.end("cmmnbj", [
      th.ladedName,
      "Fnt",
      th.fnt.exprtData(th._evaluatrOptn.fntExtraPrperte),
    ]);
  }
  fallback(handler) {
    f (!th.fnt.data) {
      return;
    }
     When fnt ladng faled, fall back t the bult-n fnt renderer.
    th.fnt.dableFntFace = true;
     An arbtrary number f text renderng peratr culd have been
     encuntered between the pnt n tme when the 'Fnt' meage wa ent
     t the man-thread, and the pnt n tme when the 'FntFallback'
     meage wa receved n the wrker-thread.
     T enure that all 'FntPath' are avalable n the man-thread, when