swc VS SonarJS

First, we switched the default compiler for new projects from Babel to SWC (Speedy Web Compiler). SWC is dramatically faster than Babel and requires zero configuration. We’ll continue to support Babel in any project currently using it.

SWC

As the reference explains “**SWC** (Speedy Web Compiler) is an extensible Rust-based platform that can be used for both compilation and bundling. Using SWC with Nest CLI is a great and simple way to significantly speed up your development process.”

This is specifically about breaking the myth that performing expensive self-contained operations (e.g, parsing GraphQL) in a native extension (C, Rust, etc.) is always faster than the interpreted language.

The JS ecosystem has the same problem, people think rewriting everything in Rust will be a magic fix. In practice, there's always the problem highlighted in the post (transitioning is expensive, causes optimization bailouts), as well as the cost of actually getting the results back into Node-land. This is why SWC abandoned the JS API for writing plugins - constantly bouncing back and forth while traversing AST nodes was even slower than Babel (e.g https://github.com/swc-project/swc/issues/1392#issuecomment-...)

Why Speedy Web Compiler ?

FTA is a TypeScript static analysis tool built on the speedy foundations of swc. FTA is fast; capable of analyzing more than 150 files per second on typical hardware, it offers a powerful addition to your code quality toolkit.

Very cool! I'm curious, is this intended for dev tooling?

For example, I could see this (or something similar) being useful as the engine for a typescript language server that would be faster than the standard one

But if it's not aimed at 1:1 with tsc, would it be intended more for something like swc[1]?

Or what would you expect people to use this for, besides just being a cool project to learn from?

[1] https://github.com/swc-project/swc

Rollup is highly configurable via plugins. It also supports a wide range of transpilation targets. However, it's written in JavaScript (well, TypeScript) so there's a ceiling on how fast it can go. esbuild and swc are orders-of-magnitude faster than Rollup.

There was already a Babel plugin for the client-preset for projects using Babel in the client-preset package. Now, as SWC itself, and Next.js is becoming more popular and uses SWC as its default compiler, there was a need for a SWC plugin as well. SWC is a fast and modern JavaScript/TypeScript compiler written in Rust, so the Babel plugin couldn't be used.

sonarlint (for better "clean code" requirements and to track cognitive complexity. Note: there is an issue with async/await/promises that is currently being fixed this month)