# tsc-rs

A Rust port of the TypeScript 7 compiler (`tsc`).

It is a direct port of Microsoft's native TypeScript compiler, which is written in Go. On the
projects we test, it gives the same diagnostics and output as that compiler, and it is faster.

This is an early release. Report problems at https://github.com/pingdotgg/ts-rust/issues.

## Use

```sh
npm install -D tsc-rs
npx tsc-rs -p tsconfig.json
```

`tsc-rs` takes the same options as `tsc`. `tsc-rs --version` prints the TypeScript version that it
ports (7.1.0-dev), not the npm version.

## Effect diagnostics

`tsc-rs` has the [Effect](https://effect.website) language service diagnostics built in (codes
377xxx), so an Effect project needs no second compiler. They come from the same check as the
TypeScript diagnostics, and the language server shows them too. They run only when the tsconfig has
the plugin, as with `@effect/language-service`:

```json
{ "compilerOptions": { "plugins": [{ "name": "@effect/language-service" }] } }
```

The rules, options and `@effect-diagnostics` comments are a port of
[Effect-TS/tsgo](https://github.com/Effect-TS/tsgo) 0.46.1. The editor features of the language
service (quick fixes, refactors, hover, completions) are not ported.

## VS Code

The TypeScript 7 extension looks for the `typescript` package, so it does not find `tsc-rs` by
itself. Point it at the dir of the `tsc` in the platform package, in `.vscode/settings.json`, and
allow it when VS Code asks:

```json
{ "js/ts.tsdk.path": "node_modules/@tsc-rs/linux-x64/lib" }
```

On macOS, use `@tsc-rs/darwin-arm64`.

## Platforms

- Linux x64 (static, any distribution)
- macOS arm64

Windows and Linux arm64 are not available yet.

## Known problems

- In some monorepos, the source files of a workspace package are reachable both through
  `node_modules` and through a direct import. There, `tsc-rs` can write output for more of those
  files than `tsc` does. (The set from `tsc` also changes from run to run there.)
- In `tsc -b`, when one project imports the output of another project without a project reference,
  `tsc-rs` can report TS2307 (cannot find module) where `tsc` happens to build the other project
  first. Add the reference to fix it.
- `tsc -b --watch` can stop with an internal error (exit code 70) after some edits.
- In the editor, memory grows slowly during long edit sessions.

## License

MIT. The port keeps the licenses and notices of TypeScript (Apache-2.0, Copyright (c) Microsoft
Corporation) and Go (BSD-3-Clause). See NOTICE.txt.