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 
expect(data.annotationType).toEqual(AnnotationType.SQUIGGLY);
        expect(data.quadPoints).toEqual([
          [
            { x: 10, y: 20 },
            { x: 20, y: 20 },
            { x: 10, y: 10 },
            { x: 20, y: 10 },
          ],
        ]);
        done();
      }, done.fail);
    });
  });
  describe("StrikeOutAnnotation", function () {
    it("should set quadints to null if not defined", function (done) {
      const strikeOutDict = new Dict();
      strikeOutDict.set("Type", Name.get("Annot"));
      strikeOutDict.set("Subtype", Name.get("StrikeOut"));
      const strikeOutRef = Ref.get(121, 0);
      const xref = new XRefMock([{ ref: strikeOutRef, data: strikeOutDict }]);
      AnnotationFactory.create(
        xref,
        strikeOutRef,
        pdfManagerMock,
        idFactoryMock
      ).then(({ data }) => {
        expect(data.annotationType).toEqual(AnnotationType.STRIKEOUT);
        expect(data.quadPoints).toEqual(null);
        done();
      }, done.fail);