Forward signals to child process

[MrJohz]

I ran into an issue where I would Ctrl-C a running process, and dotenv-cli would forward the resulting SIGINT signal to the child process, but would also immediately terminate, leaving the child process in a kind of zombie state.

You can see this in action using the following test file:

import { once } from "node:events";

// simulate a long-running process, e.g. a server
// that should only quit when SIGINT is received
const handle = setInterval(() => {}, 5000);

console.log("Running, press Ctrl+C to exit.");

await once(process, "SIGINT");
console.log("Received SIGINT, will exit in 5 seconds...");

setTimeout(() => {
  console.log("Exiting.");
  clearInterval(handle);
}, 5000);

This should produce the following output (pressing Ctrl+C at the appropriate time):

$ node test.mjs
Running, press Ctrl+C to exit.
^CReceived SIGINT, will exit in 5 seconds...
Exiting.
$

Note that the new shell prompt appears once the script has fully exited.

Running npx dotenv -- node test.mjs currently will produce the following output (again, pressing Ctrl+C at the appropriate time).

$ node test.js
Running, press Ctrl+C to exit.
^CReceived SIGINT, will exit in 5 seconds...
$ Exiting.

Note that the prompt appears once the parent dotenv program has finished, but the child test.mjs continues running after this point.

This PR explicitly forwards a number of signals to the child process. This ensures that the signals are not handled in dotenv-cli itself, but always in the child process, which prevents the above case where the parent process terminates prematurely.

I have added a bunch of signals that I think should be relevant in various cross-platform situations, but I'm not wedded to this particular set of signals here.

[entropitor]

https://github.com/entropitor/dotenv-cli/releases/tag/v7.4.3