Object.freeze, Object.seal and Object.preventExtensions of a class instance held in an untyped value threw SC2020 at run time. Node changes the instance itself: writes through its typed references then throw the read-only TypeError in strict mode code, adding properties through any reference fails, and Object.isFrozen, isSealed and isExtensible report the state through either reference. - In a program that freezes, seals or prevents extensions of an untyped value that is not a fresh literal, every class hierarchy that can be held there gets the integrity word that static Object.freeze already uses, and with it the existing write checks. - The runtime applies the operation to the instance's checked view and commits the view. The commit of such a hierarchy stores the view's integrity state in the word (scr_dyn_class_view_integrity) and makes the instance's property bag not extensible with it. A hierarchy without the word still throws SC2020. - These commits replace and remove the bag's field entries whatever their attributes, so a sealed or frozen view does not leave stale field values in the bag. - The analysis behind records and arrays now starts from these calls only, rather than from every untyped freeze the lowering emits, such as the frozen strings array of a tagged template. - Programs without such calls compile as before. The runtime ABI moves to v38. Corpus 7407 covers freeze, seal and preventExtensions through unknown of classes and subclasses, writes through typed and untyped references and through methods, properties added before and after the operation, and the integrity queries, and matches Node. Refs #1374 Co-authored-by: blurname <50226652+blurname@users.noreply.github.com>
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
- Introduction: what scriptc is and what you can build.
- Quickstart: installation and your first executable.
- Coverage reports: check whether an existing program compiles.
- Platform support: cross-compilation and WebAssembly.
- CLI reference: commands, options, and output formats.
- Native program objects: use compiler output in external builds.
- Native FFI: call C ABI functions from compiled programs.
- WebAssembly modules: build and embed WASI modules.
- Examples: programs and integration examples in this repository.
Contributing
See CONTRIBUTING.md for source setup, testing, native artifact builds, and docs development.