test-child-process-promisified.js

'use strict';
const common = require('../common');
const assert = require('assert');
const child_process = require('child_process');
const { promisify } = require('util');

const exec = promisify(child_process.exec);
const execFile = promisify(child_process.execFile);

// The execPath might contain chars that should be escaped in a shell context.
// On non-Windows, we can pass the path via the env; `"` is not a valid char on
// Windows, so we can simply pass the path.
const execNode = (args) => exec(
  `"${common.isWindows ? process.execPath : '$NODE'}" ${args}`,
  common.isWindows ? undefined : { env: { ...process.env, NODE: process.execPath } },
);

{
  const promise = execNode('-p 42');

  assert(promise.child instanceof child_process.ChildProcess);
  promise.then(common.mustCall((obj) => {
    assert.deepStrictEqual(obj, { stdout: '42\n', stderr: '' });
  }));
}

{
  const promise = execFile(process.execPath, ['-p', '42']);

  assert(promise.child instanceof child_process.ChildProcess);
  promise.then(common.mustCall((obj) => {
    assert.deepStrictEqual(obj, { stdout: '42\n', stderr: '' });
  }));
}

{
  const promise = exec('doesntexist');

  assert(promise.child instanceof child_process.ChildProcess);
  promise.catch(common.mustCall((err) => {
    assert(err.message.includes('doesntexist'));
  }));
}

{
  const promise = execFile('doesntexist', ['-p', '42']);

  assert(promise.child instanceof child_process.ChildProcess);
  promise.catch(common.mustCall((err) => {
    assert(err.message.includes('doesntexist'));
  }));
}
const failingCodeWithStdoutErr =
  'console.log(42);console.error(43);process.exit(1)';
{
  execNode(`-e "${failingCodeWithStdoutErr}"`)
    .catch(common.mustCall((err) => {
      assert.strictEqual(err.code, 1);
      assert.strictEqual(err.stdout, '42\n');
      assert.strictEqual(err.stderr, '43\n');
    }));
}

{
  execFile(process.execPath, ['-e', failingCodeWithStdoutErr])
    .catch(common.mustCall((err) => {
      assert.strictEqual(err.code, 1);
      assert.strictEqual(err.stdout, '42\n');
      assert.strictEqual(err.stderr, '43\n');
    }));
}