Workaround for incorrectly identified drill file

[ju5t]

It should probably be enough to change stackupZip to the following code (and include whats-that-gerber):

function stackupZip(zip) {
  return jszip.loadAsync(zip)
    .then(zip => {
      const files = [];
      zip.forEach((path, file) => {
        if (!file.dir) {
          const layerType = whatsThatGerber(file)
          files.push(
            file
              .async("text")
              .then(contents => ({
                gerber: contents,
                filename: path,
                options: {
                  filetype: (layerType === 'drl') ? 'drill' : 'gerber'
                }
              }))
          );
        }
      });
      return Promise.all(files);
    })
}

Ref:
mcous/gerber-plotter#14 (comment)
mcous/gerber-parser#23

[mcous]

Just FYI, this is actually a workaround for mcous/gerber-parser#23

[ju5t]

@mcous thanks, I've updated the subject and description.

[ju5t]

It turns out that const layerType = whatsThatGerber(file) should be const layerType = whatsThatGerber(path).