Malte UblandClaude Opus 5.5 b200bde558 Read a generic constraint member the instantiation omits
`options.sessionId` inside a generic function whose type parameter's
constraint declares `sessionId?: string` fenced with SC1090 when the call
site's options record has no such slot:

  function applyAuth<TModel, TOptions extends ProviderRequestOptions<TModel> & Transforms>(
    model: TModel, options: TOptions | undefined) {
    const sessionId =
      options && "sessionId" in options && typeof options.sessionId === "string"
        ? options.sessionId : undefined;
  }
  applyAuth(model, { apiKey, azureApiVersion });

The checker admits the read through the constraint (and, with the `in`
guard, through a synthetic `T & Record<"sessionId", unknown>`), while the
instantiated record — the value's actual layout — stores no such field.
`fieldTarget` found no record slot and the read fell through to the
generic unsupported-property fence, even though Node simply reads the
property off the object it has: undefined when the caller omitted it, the
extra property when a JavaScript caller supplied one.

fieldTarget now recognizes a generic receiver (a type parameter, or an
`in`-narrowed intersection that contains one) whose stored record lacks
the member, and lowers the read as the checked-dynamic keyed read of that
record value, entering the static code at the type the checker gave the
read. Reads that keep a slot take their record get as before, and the
programs this path opens did not compile at all before, so typed code
keeps its representation.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-29 05:38:14 -07:00
2026-10-27 23:21:09 -05:00
2026-10-28 20:50:23 -05:00
2026-10-16 10:33:14 -05:00
2026-10-27 23:21:09 -05:00
2026-10-14 17:27:02 -05:00
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2026-10-27 16:45:14 -05:00
2026-10-25 21:21:26 -05:00
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.

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