PDF.js version: 3.5.141

These two properties should be marked as not mandatory as they are initialized if not present
) {
    this._currentScaleValue = newValue.toString();
    if (this.#isSameScale(newScale)) {
      if (preset) {
        this.eventBus.dispatch("scalechanging", {
          source: this,
          scale: newScale,
          presetValue: newValue,
        });
      }
      return;
    }
    this.viewer.style.setProperty(
      "--scale-factor",
      newScale * PixelsPerInch.PDF_TO_CSS_UNITS
    );
    const postponeDrawing = drawingDelay >= 0 && drawingDelay < 1000;
    this.refresh(true, {
      scale: newScale,
      drawingDelay: postponeDrawing ? drawingDelay : -1,
    });
    if (postponeDrawing) {
      this.#scaleTimeoutId = setTimeout(() => {
        this.#scaleTimeoutId = null;
        this.refresh();
      }, drawingDelay);
    }
    this._currentScale = newScale;
    if (!noScroll) {
      let page = this._currentPageNumber,