Hi,
The CRAN package in its DESCRIPTION file links to the GitHub repo. Which shows inhttps://github.com/juba/scatterD3#development-noteshow to bundle the (not in the package by design) source dir srcjs/ into a compacted file by using node / npm. (Disclaimer: I know little JS myself)
This is perfectly correct. The JavaScript source code of scatterD3 is in the srcjs directory in this Github repository. The compressed JS code in the R package is the result of the bundling command given in the README.
Let me know if you have any other question. Thanks for your efforts on packaging scatterD3 for debian ! -- Julien