@dodec Or just crowdsource your error finding! Post it on the internet, and within minutes, every error will have been meticulously pointed out. (and, if you post it on the right part of the internet, you might not even get mocked for it!)
@Rosemary Well, it's up on NPM and GitHub, at least (https://www.npmjs.com/package/pixelfonts and https://github.com/byackley/pixelfonts). So far you're the only person who's pointed anything out.
@dodec Ah, well, I was being facetious anyway! If I notice any other mistakes, I'll let you know. Though I'm unlikely to, as we have no particular need to use this font.
@Rosemary Oops - no, it's not. This is why I need to find more text files to test this out with (some of the box-drawing tests at the bottom of the file reveal similar problems).