In the following spots a "MouseUp" eventName is being used, which does look inconsistent considering that the "Mouse Down"/"Mouse Enter"/"Mouse Exit" eventNames all have a space in them.
Is this inconsistency actually expected, or is it a simple typo? If the former, then a comment explaining *why* would be appropriate; otherwise we should just fix this :-)

 - https://github.com/mozilla/pdf.js/blob/25b84ce84c95ba06d1ee57e578672048269c39c1/src/display/annotation_layer.js#L806

 - https://github.com/mozilla/pdf.js/blob/25b84ce84c95ba06d1ee57e578672048269c39c1/src/display/annotation_layer.js#L945

 - https://github.com/mozilla/pdf.js/blob/25b84ce84c95ba06d1ee57e578672048269c39c1/src/display/annotation_layer.js#L1034

 - https://github.com/mozilla/pdf.js/blob/25b84ce84c95ba06d1ee57e578672048269c39c1/src/display/annotation_layer.js#L1168

/cc @calixteman 
AnnotationFactory.create(
        xref,
        annotationRef,
        pdfManagerMock,
        idFactoryMock
      ).then(({ data }) => {
        expect(data.annotationType).toBeUndefined();
        done();
      }, done.fail);
    });
  });
  describe("getQuadPoints", function () {
    let dict, rect;
    beforeEach(function (done) {
      dict = new Dict();
      rect = [];
      done();
    });
    afterEach(function () {
      dict = null;
      rect = null;
    });
    it("should ignore missing quadints", function () {
      expect(getQuadPoints(dict, rect)).toEqual(null);
    });
    it("should ignore non-array values", function () {
      dict.set("QuadPoints", "foo");
      expect(getQuadPoints(dict, rect)).toEqual(null);
    });
    it("should ignore arrays where the length is not a multiple of eight", function () {