Function wrapHook

lib/internal/modules/customization_hooks.js:183–196

* Helper function to wrap around invocation of user hook or the default step * in order to fill in missing arguments or check returned results. * Due to the merging of the context, this must be a closure. * @param {number} index Index in the chain. Default step is 0, last added hook is 1,

(index, userHookOrDefault, next)

   * @returns {Function} Wrapped hook or default step.
   */
  function wrapHook(index, userHookOrDefault, next) {
    return function nextStep(arg0, context) {
      lastRunIndex = index;
      if (context && context !== mergedContext) {
        ObjectAssign(mergedContext, context);
      }
      const hookResult = userHookOrDefault(arg0, mergedContext, next);
      if (lastRunIndex > 0 && lastRunIndex === index && !hookResult.shortCircuit) {
        throw new ERR_INVALID_RETURN_PROPERTY_VALUE('true', name, 'shortCircuit',
                                                    hookResult.shortCircuit);
      }
      return validate(arg0, mergedContext, hookResult);
    };
  }
  const chain = [wrapHook(0, defaultStep)];
  for (let i = 0; i < hooks.length; ++i) {
    const wrappedHook = wrapHook(i + 1, hooks[i][name], chain[i]);