I used to have all npm modules in source control (SCM), until npm introduced tree shaking. I'm using ZFS which have both de-duplication and compression, so I gain very little by tree shaking. I wish there was a way to disable tree shaking in npm, it's really the source of all evil. Anyway, I reviewed all code diffs after each npm update, very little changed, eg. it wasn't that much work. But it's now impossible as npm moves files around. I also deleted a lot of unnecessary files. About 90% of the content of each NPM packages are not needed.

Another reason why I stopped hosting dependencies in SCM is native modules. I wish Node.JS itself could become a platform layer so that I wouln't have to use these native modules.

Another thing is compile to JS, where a tiny change in the source might cause a huge diff in the generated JS.