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 
this.inputs.push({ name, data });
    },
  };
  let pdfManagerMock, idFactoryMock, partialEvaluator;
  beforeAll(async function (done) {
    pdfManagerMock = new PDFManagerMock({
      docBaseUrl: null,
    });
    const CMapReaderFactory = new DefaultCMapReaderFactory({
      baseUrl: CMAP_PARAMS.cMapUrl,
      isCompressed: CMAP_PARAMS.cMapPacked,
    });
    const builtInCMapCache = new Map();
    builtInCMapCache.set(
      "UniJIS-UTF16-H",
      await CMapReaderFactory.fetch({ name: "UniJIS-UTF16-H" })
    );
    builtInCMapCache.set(
      "Adobe-Japan1-UCS2",
      await CMapReaderFactory.fetch({ name: "Adobe-Japan1-UCS2" })
    );
    idFactoryMock = createIdFactory( 0);
    partialEvaluator = new PartialEvaluator({
      xref: new XRefMock(),
      handler: new HandlerMock(),
      pageIndex: 0,
      idFactory: createIdFactory( 0),
      fontCache: new RefSetCache(),
      builtInCMapCache,
    });