cpython/Tools/wasm/emscripten/node_pre.js

// If process is undefined, we're not running in the node runtime let it go I
// guess?
if (typeof process !== "undefined") {
    const nodeVersion = Number(process.versions.node.split(".", 1)[0]);
    if (nodeVersion < 18) {
        process.stderr.write(
            `Node version must be >= 18, got version ${process.version}\n`,
        );
        process.exit(1);
    }
    Module.preRun = () => {
        FS.mkdirTree("/lib/");
        FS.mount(NODEFS, { root: __dirname + "/lib/" }, "/lib/");
    };
}