deno_repl.js

// This REPL evaluates JavaScript in a Deno process.

// If you provide environment variables via 'env', don't forget to include
// "--allow-env" in the 'args' array.

/*jslint node */

import child_process from "node:child_process";
import console from "node:console";
import process from "node:process";
import make_cmdl from "./cmdl.js";
import make_cmdl_repl from "./cmdl_repl.js";
const padawan_url = new URL("./deno_padawan.js", import.meta.url);

function allow_host(run_args, host) {

// Deno only permits the --allow-net argument to appear once in its list of run
// arguments. This means we need to jump thru hoops to avoid any duplication.

    if (run_args.includes("--allow-all") || run_args.includes("--allow-net")) {

// All hosts are already allowed.

        return run_args;
    }

// If the specific form of --allow-net is present, we append 'host' onto its
// list of hosts.

    run_args = run_args.map(function (arg) {
        return (
            arg.startsWith("--allow-net=")
            ? arg + "," + host
            : arg
        );
    });

// Otherwise we add the --allow-net.

    return (
        !run_args.some((arg) => arg.startsWith("--allow-net="))
        ? run_args.concat("--allow-net=" + host)
        : run_args
    );
}

function spawn_deno_padawan(tcp_port, which, args = [], env = {}) {
    return Promise.resolve(child_process.spawn(
        which,
        [
            "run",
            ...allow_host(args, "127.0.0.1:" + tcp_port),
            padawan_url.href,
            String(tcp_port)
        ],
        {
            env: Object.assign({NO_COLOR: "1"}, env)
        }
    ));
}

function make_deno_repl(capabilities, which, args, env) {
    return make_cmdl_repl(capabilities, function spawn_padawan(tcp_port) {
        return spawn_deno_padawan(tcp_port, which, args, env);
    });
}

if (import.meta.main) {
    const cmdl = make_cmdl(
        function spawn_padawan(tcp_port) {
            return spawn_deno_padawan(
                tcp_port,
                "deno",
                ["--allow-net=deno.land"]
            );
        },
        function on_stdout(chunk) {
            return process.stdout.write(chunk);
        },
        function on_stderr(chunk) {
            return process.stderr.write(chunk);
        }
    );
    cmdl.create().then(function () {
        return cmdl.eval(
            `$imports[0].basename("/a/b/c.d")`,
            ["https://deno.land/std@0.117.0/path/mod.ts"]
        ).then(
            console.log
        );
    }).then(cmdl.destroy);
}

export default Object.freeze(make_deno_repl);