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 
function (done) {
        const parentDict = new Dict();
        parentDict.set("Parent", null);
        parentDict.set("T", "foo");
        widgetDict.set("Parent", parentDict);
        widgetDict.set("T", "bar");
        const widgetRef = Ref.get(22, 0);
        const xref = new XRefMock([{ ref: widgetRef, data: widgetDict }]);
        AnnotationFactory.create(
          xref,
          widgetRef,
          pdfManagerMock,
          idFactoryMock
        ).then(({ data }) => {
          expect(data.annotationType).toEqual(AnnotationType.WIDGET);
          expect(data.fieldName).toEqual("foo.bar");
          done();
        }, done.fail);
      }
    );
  });
  describe("TextWidgetAnnotation", function () {
    let textWidgetDict, helvRefObj, gothRefObj;
    beforeEach(function (done) {
      textWidgetDict = new Dict();
      textWidgetDict.set("Type", Name.get("Annot"));
      textWidgetDict.set("Subtype", Name.get("Widget"));
      textWidgetDict.set("FT", Name.get("Tx"));
      const helvDict = new Dict();
      helvDict.set("BaseFont", Name.get("Helvetica"));