fix: exit shell process on terminal close

[kittaakos]

What it does

Check exitStatus.code instead of checking the falsyness of the exitStatus. The latter is always truthy with the exit reason support.

Ref: #12293

Closes: #13346

How to test

From #13346 (comment):

Steps to Reproduce:

1. Open two Terminal tabs.
2. In one them them, start a long-running process, such as the yes command.
3. In the other tab, use ps -ef or top to see the process running.
4. Close the Terminal with the long-running process.
5. Observe that the process is still running somewhere in the background.

fix_theia_11997.mov

Follow-ups

Breaking changes

• This PR introduces breaking changes and requires careful review. If yes, the breaking changes section in the changelog has been updated.

Attribution

Review checklist

• As an author, I have thoroughly tested my changes and carefully followed the review guidelines

Reminder for reviewers

• As a reviewer, I agree to behave in accordance with the review guidelines

[kittaakos]

This PR should also close #12715. Closing the terminal for the long-running tasks sends the SIGHUP signal to the task process and terminates it.

OP of #12715 expects the following:

• Run workspace tasks as a live service like server ( "react-native start" -> metro bundler using 8081 port)
• Close the task terminal but keep the task running.

This is not the correct expectation. Closing the terminal window of the task must terminate the underlying process.

.vscode/tasks.json:

{
  "version": "2.0.0",
  "tasks": [
    {
      "label": "Run HTTP Server",
      "command": "node index.js",
      "type": "shell"
    }
  ]
}

index.js:

const http = require('http');
const port = 4567;
const hostname = '127.0.0.1';
const server = http.createServer(function (req, res) {
    res.writeHead(200, { 'Content-Type': 'text/plain' });
    res.end('Hello World!\n');
});
server.listen(port, hostname, () => {
    console.log(`Node.js web server at ${hostname}:${port} is running..`);
});

Open the browser on 127.0.0.1:4567 and see that it works when the task runs. When the terminal window is closed, the task terminates:

fixes_12715.mov