nx buildable libraries use case - how large must the repo be

[rvdven123]

Hi,

We have a repo with about 12 libraries (main.js bundle is 3.47 MB).
Without running tests, a build with nx serve --with-deps and changing code in one of the libraries (with no dependencies) has the same build time as running ng serve cold (about 60/70 seconds).

How is this possible ? Is the repo too small for the nx use case ?

[Bielik20]

Hello, this is an interesting issue. I have also a medium size project where I tested --buildLibsFromSource false. My findings was that entire backend builds:

• with --buildLibsFromSource false in 24s + time to build libs
• with --buildLibsFromSource true in 25s (no time building libs)

So this is absolutely useless (in this particular example) to use buildable libs as the time to build them is much greater than any possible gain I could get. I also wonder if someone is getting benefits from those buildable libs and how big your project must be to see them.

[belaczek]

We have the same experience and our project is actually quite large (~500k LOC) with multiple large or small libraries. Talking in real numbers, rebuild of the main application with buildLibsFromSource: true takes around 7 minutes. With buildLibsFromSource: false and enabled incremental build, it takes 8 minutes and that's with warm cache on all libs. With cold cache, the complete rebuild gets to around 15 minutes.
I'm curious if that is a limitation of webpack and/or related tooling, or if there's just some missing piece, which is not properly implemented yet. We were doing some experiments like explicitly excluding buildable libraries from transpilation of the main app, but without much difference.

[kuzaxak]

Are you using typescript for buildable libraries? @belaczek