[Study] Rollup: replace plugin typescript by plugin swc about faency

[paulocfjunior]

Findings

Currently, when using swc for typescript projects, we are still required to run tsc to generate the .d.ts files. This is the most time-consuming part of the build (taking around 40 sec to finish). The swc compiler takes only half a second to finish.

ℹ️ Our current build structure takes 110 seconds to generate the dist folder.

swc is planning to generate the .d.ts files by itself as it's mentioned in this article (and this issue) which will allow users to get rid of tsc. It will also be able to bundle the files, so it may replace rollup itself.

On the other hand, the Typescript team seems to be aware that there's room to improve the tsc building/type-checking speed, they just don't seem to prioritize that right now, but there's a possibility that they do something about it in the future.

Test results

I was able to build the lib using swc + tsc.

The whole process took 45s.

Caveat

SWC doesn't seem to support Tree Shaking right now (detected by inspecting the .next dir of the target app), and it's a mandatory point to allow us to go forward on it, once we currently have this optimization.

According to the swc project it should be implemented (ref 1, ref 2 - via spack), but this package doesn't exist at this moment (IDK if existed already or if it's still to be done).

Conclusion

From here, we should:

• Keep the current build structure (maybe just upgrade the libs used) and wait for swc to be ready to support Tree Shaking and generate .d.ts files.
• Use combination of swc + tsc to have the build working 2,5x faster, having in mind that swc is under heavy development.

[seedy]

Closing with conclusions validated