Function runMain

bin/script-util.js:129–172

* Run a function if the module is the main entry for `node` process. * * @param currentModule - Current module. It's used to determine if the module * is the main entry script for `node` * @param {*} fn - An function. It can be sync or async. The return or resolved * value is handled as follows

(currentModule, fn, ...args)

 * @param {*} args - Arguments for the function
 */
function runMain(currentModule, fn, ...args) {
  assert(
    typeof currentModule === 'object' && currentModule.filename,
    'The first argument must be a module object',
  );
  assert(typeof fn === 'function', 'The second argument must be a function');
  // Only run the function if the module is the main entry script for `node`
  if (require.main !== currentModule) return;

  // Error handler
  const handleError = err => {
    console.error(err);
    process.exit(err.exitCode || 1);
  };

  // Return handler
  const handleReturn = val => {
    if (val != null) {
      if (val === true) return;
      if (val === false) {
        process.exit(1);
      }
      if (typeof val === 'object' && typeof val.exitCode === 'number') {
        process.exit(val.exitCode);
      } else {
        console.log(val);
      }
    }
  };
  let valueOrPromise;
  try {
    valueOrPromise = fn(...args);
    if (typeof valueOrPromise.then === 'function') {
      // Handle the promise
      valueOrPromise.then(handleReturn, handleError);
    } else {
      // Handle the return value
      handleReturn(valueOrPromise);
    }
  } catch (err) {
    // Handle error thrown synchronously
    handleError(err);
  }
}

exports.isDryRun = isDryRun;
exports.isJsonEqual = isJsonEqual;