Quick start

This page compiles a file, then a project, then type-checks without writing anything. It assumes tsc-rs is on your PATH; see Installation.

Compile one file#

Create queue.ts:

Open in playground

export enum Priority {
  Low,
  High,
}

interface Job<T> {
  id: number;
  payload: T;
  priority: Priority;
}

export class Queue<T> {
  private jobs: Job<T>[] = [];

  push(payload: T, priority = Priority.Low): Job<T> {
    const job: Job<T> = { id: this.jobs.length + 1, payload, priority };
    this.jobs.push(job);
    return job;
  }

  next(): Job<T> | undefined {
    return this.jobs.shift();
  }
}

Compile it:

tsc-rs --strict --target es2022 --module esnext --outDir out queue.ts

out/queue.js now contains:

export var Priority;
(function (Priority) {
    Priority[Priority["Low"] = 0] = "Low";
    Priority[Priority["High"] = 1] = "High";
})(Priority || (Priority = {}));
export class Queue {
    jobs = [];
    push(payload, priority = Priority.Low) {
        const job = { id: this.jobs.length + 1, payload, priority };
        this.jobs.push(job);
        return job;
    }
    next() {
        return this.jobs.shift();
    }
}

Compile a project#

Generate a starter tsconfig.json, then compile everything it includes:

tsc-rs --init
tsc-rs -p tsconfig.json

Add -w to recompile on change:

tsc-rs -w -p tsconfig.json

Warning

With outDir, tsc-rs 0.4.1 writes every file directly into that directory and does not recreate source subdirectories. For nested sources, leave outDir unset so each .js file lands next to its source. Projects and watch covers this and the other project build differences.

See tsconfig support for the options tsc-rs applies.

Type-check only#

tsc-rs --noEmit --strict src/index.ts

Diagnostics use the tsc format and codes, and the process exits with status 1. For a file with two mistakes:

user.ts(7,27): error TS2339: Property 'nmae' does not exist on type 'User'.
user.ts(10,7): error TS2322: Type 'string' is not assignable to type 'number'.

Found 2 errors in 1 file.

When the checker reports errors, tsc-rs writes no output files. This differs from tsc, which emits by default.

Warning

The type checker is incomplete. It misses some errors that tsc reports and reports some that tsc does not. The conformance report quantifies both.

Transpile without checking#

When you only need JavaScript, skip the checker:

tsc-rs --transpileOnly --outDir out src/index.ts

Add --fast-emit to also skip cosmetic formatting normalization. The output is valid JavaScript but is not formatted the way tsc would format it. This is the mode bundlers and runtimes want.

Next#

Found a mistake on this page? Open an issue on GitHub.