Issue with naming of Poly Line

  [
    geojson.point(gj),
    geojson.line(gj),
    geojson.polygon(gj),
    geojson.multipolygon(gj),
    geojson.multiline(gj),
  ].forEach(function (l) {
    if (l.geometries.length && l.geometries[0].length) {
      write(
        // field definitions
        l.properties,
        // geometry type
        l.type,
        // geometries
        l.geometries,
        function (err, files) {
          var fileName =
            options && options.types && options.types[l.type.toLowerCase()]
              ? options.types[l.type.toLowerCase()]
              : l.type;
          zipTarget.file(fileName + ".shp", files.shp.buffer, { binary: true });
          zipTarget.file(fileName + ".shx", files.shx.buffer, { binary: true });
          zipTarget.file(fileName + ".dbf", files.dbf.buffer, { binary: true });
          zipTarget.file(fileName + ".prj", prj);
        }
      );
    }
  });
  

When a geojson with linestring is being added, the shp type returned is polyline. But there is no option to edit the polyline name under shpwritedownloadoptions/zip optiosn

  export interface DownloadOptions {
    folder?: string;
    filename?: string;
    prj?: string;
    types?: {
      point?: string;
      polygon?: string;
      line?: string;
      multipolygon?: string;
      multiline?: string;
    };
  }

Start with the download code shown in the issue and the DownloadOptions interface, tracing how l.type is converted into the output filename. Add an option for the line geometry's returned polyline name, then verify that the corresponding .shp, .shx, .dbf, and .prj files use that name.