Chris Tate 05cb9bd609 Add the concurrency test option
node:test changes, matching Node 24.22:

- { concurrency } on describe, suite, test, it and t.test sets how many
  subtests run at once: a number, true for os.availableParallelism() - 1,
  or false for 1. Subtests inherit the parent's value.
- Above 1, each subtest runs on its own fiber. Subtests start in
  declaration order as slots free up, and t.test and test() calls inside a
  concurrent test start the subtest at once; t.test's promise settles when
  it finishes. The parent finishes after all of them.
- Results, diagnostics and failures are reported in declaration order.
- A concurrent subtest waits after its beforeEach hooks, and a concurrent
  suite before its children, for as many turns as Node's runner does, so
  sibling bodies interleave as they do there.
- A concurrency that is not an integer from 1 to 4294967295 throws Node's
  ERR_OUT_OF_RANGE RangeError when the test or suite is created.
- Nested test() calls and hooks inside a concurrent subtest attach to the
  subtest that runs on the calling fiber.

The concurrency fixture compares the reporter output, the order of the
bodies' side effects, and the range errors with Node, plain and with
SCRIPTC_SAN=1.
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2026-07-22 18:08:04 -05:00

scriptc

Vercel Labs Experiment npm version: scriptc License: Apache-2.0 npm downloads per month: scriptc

scriptc compiles TypeScript and JavaScript to native executables and WebAssembly. It uses the types checked by the TypeScript compiler to generate machine code, and the output runs without Node.js installed. npm packages your program imports compile along with it. Code scriptc can't compile is reported at build time with a diagnostic and, where available, a rewrite hint.

scriptc is experimental and supports a subset of JavaScript, TypeScript, and Node.js APIs. Run scriptc coverage on an existing program to see how much of it compiles, and see the limitations and Node.js compatibility reference for details.

Installation

Install with Node.js 24 or later and npm:

$ npm install -g scriptc

The installed compiler runs natively on macOS, Linux, and Windows. Node.js is needed only to install it and to run WASI modules with scriptc run. Standalone compiler archives are also available from GitHub Releases.

Building executables requires a linker and the platform SDK or sysroot. See the quickstart for prerequisites and platform support for host requirements, cross-compilation, and WebAssembly.

Build a program

Create hello.ts:

const who = process.argv.length > 2 ? process.argv[2] : "world";
console.log(`hello, ${who}`);

scriptc run compiles the file and runs the result:

$ scriptc run hello.ts
hello, world

scriptc build writes an executable:

$ scriptc build hello.ts -o hello >/dev/null
$ ./hello scriptc
hello, scriptc

These examples use POSIX shell syntax. On Windows, build hello.exe and run it with .\hello.exe.

Use scriptc coverage hello.ts to check what compiles before you build. See coverage reports for details.

Use Node APIs

Supported Node APIs compile to the native runtime. For example, server.ts:

import { createServer } from "node:http";

const server = createServer((req, res) => {
  res.setHeader("content-type", "application/json");
  res.end(JSON.stringify({ path: req.url }));
});

server.listen(8080, () => {
  console.log("listening on http://localhost:8080");
});
$ scriptc build server.ts -o server >/dev/null
$ ./server
listening on http://localhost:8080

Use npm packages

npm packages compile into the executable with your code, so it doesn't read node_modules at runtime.

Create cli.ts:

import pc from "picocolors";

console.log(pc.green("hello from scriptc"));
$ npm install picocolors
$ scriptc build cli.ts -o cli >/dev/null
$ ./cli
hello from scriptc

Package support is partial. See npm dependencies for which packages compile and how to check them.

Documentation

Contributing

See CONTRIBUTING.md for source setup, testing, native artifact builds, and docs development.

S
Description
GitHub Trending: vercel-labs/scriptc
Readme Apache-2.0
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