Function buildHooks

lib/internal/modules/customization_hooks.js:171–203

* Convert a list of hooks into a function that can be used to do an operation through * a chain of hooks. If any of the hook returns without calling the next hook, it * must return shortCircuit: true to stop the chain from continuing to avoid * forgetting to invoke the next hook by mistake. * @p

(hooks, name, defaultStep, validate, mergedContext)

 * @returns {any}
 */
function buildHooks(hooks, name, defaultStep, validate, mergedContext) {
  let lastRunIndex = hooks.length;
  /**
   * 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,
   *   and so on.
   * @param {Function} userHookOrDefault Either the user hook or the default step to invoke.
   * @param {Function|undefined} next The next wrapped step. If this is the default step, it's undefined.
   * @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]);
    ArrayPrototypePush(chain, wrappedHook);
  }
  return chain[chain.length - 1];
}

/**
 * @typedef {object} ModuleResolveResult