Spinner pauses when using child_process.execSync

[TotomInc]

Spinner pauses when I start a command using child_process.execSync.

Is this intended? Did I need to manually render the frames using ora.render()?

[sindresorhus]

JavaScript is single-threaded, so running a synchronous function blocks everything else, including Ora. Use exec instead.

[eli8levit]

If so, why it does work and doesn't pause the spinner?

async function run() {
  spinner.start('Installing packages...');
  await install('npm install');
  spinner.succeed('Installed');
}

function install() {
  return new Promise((resolve, reject) => {
    exec('npm install').on('close', code => {
      if (code === 0) {
        resolve();
      }
      reject();
    });
  });
}

run();

[sindresorhus]

@jediyozh Because exec is asynchronous, not synchronous.

[eli8levit]

@sindresorhus of course but I made it synchronous with Promise, no?

[sindresorhus]

@jediyozh No. I would recommend reading up on how promises and async/await work. In short, await only pauses the execution context of the function, not the whole process.

[eli8levit]

@sindresorhus Got it. Thanks for the explanation and for the great tool 👍

[sindresorhus]

Also, I would recommend execa instead of exec. It's Promise-friendly and more user-friendly.

[eli8levit]

@sindresorhus I will look at this