Thanks @amosbastian.
Thanks for the kind comments.
hexo should be quite popular with ~27,000 stars and ~50,000 "used by" on GitHub, and it's among the top static site generation tools and blog framework for years (competitors like Jekyll).
Yes. the change itself doesn't need thousands of lines of code, and mainly requires understanding about the framework. The fix to the defect in hexo project is also kind of one-line change. :)
In engineering world, the tests are so important to ensure the quality. I know a lot of utopian submission don't have good tests, but that's what utopian could help to produce / encourage high-quality open source projects. :P