ts-loader VS swc

It'll be a little different than your typical "what is webpack?" article in that I write this as the maintainer of ts-loader, a loader used for integrating TypeScript with webpack. I've worked in the webpack ecosystem for some years now, and I'll share some of my experiences with you.

why I use @babel/preset-typescript over ts-loader and awesome-typescript-loader to complie TypeScript? it's blazingly faster than the others and has more perks(read #4) ts-loader doesn't natively support HMR(Hot Module Replacement) awesome-typescript-loader's latest release is on Jun 22, 2018 TypeScript With Babel: A Beautiful Marriage - Matt Turnbull's Post

Okay. The normal setup is that you use https://github.com/TypeStrong/ts-loader or https://github.com/TypeStrong/fork-ts-checker-webpack-plugin as part of your Webpack config. Those will run the TS compilation step as part of the Webpack processing sequence.

I've recently tried SWC for building my project instead of ts-loader and was blown away by its performance (I got 8x-10x speedup on a Windows machine).

{ "compilerOptions": { "target": "esnext", "module": "esnext", "strict": true, "jsx": "preserve", "importHelpers": true, "moduleResolution": "node", "experimentalDecorators": true, "skipLibCheck": true, "esModuleInterop": true, "allowSyntheticDefaultImports": true, "sourceMap": true, "baseUrl": "./", "outDir": "./dist", // https://github.com/TypeStrong/ts-loader/issues/1138 "importsNotUsedAsValues": "preserve", "types": [ "webpack-env" ], "paths": { "@/*": [ "src/*" ], "@shared/*": [ "../shared/*" ] }, "lib": [ "esnext", "dom", "dom.iterable", "scripthost" ] }, "include": [ "src/**/*.ts", "src/**/*.tsx", "src/**/*.vue", "tests/**/*.ts", "tests/**/*.tsx", "../shared/**/*" ], "exclude": [ "node_modules" ] }

See https://github.com/TypeStrong/ts-loader#happypackmode. Switching to esbuild-loader cut my build time in half.

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

This is... good news, but I still cannot fathom using the default Typescript compiler for regular development. Seriously, leave the type-checking to your IDE and CICD chain, and switch to using tsx (https://www.npmjs.com/package/tsx) or swc (https://swc.rs/) and you will _immediately_ notice the difference in speed and productivity.