Current File : //lib/node_modules/pm2/node_modules/async/waterfall.js
'use strict';
Object.defineProperty(exports, "__esModule", {
value: true
});
var _once = require('./internal/once.js');
var _once2 = _interopRequireDefault(_once);
var _onlyOnce = require('./internal/onlyOnce.js');
var _onlyOnce2 = _interopRequireDefault(_onlyOnce);
var _wrapAsync = require('./internal/wrapAsync.js');
var _wrapAsync2 = _interopRequireDefault(_wrapAsync);
var _awaitify = require('./internal/awaitify.js');
var _awaitify2 = _interopRequireDefault(_awaitify);
function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
/**
* Runs the `tasks` array of functions in series, each passing their results to
* the next in the array. However, if any of the `tasks` pass an error to their
* own callback, the next function is not executed, and the main `callback` is
* immediately called with the error.
*
* @name waterfall
* @static
* @memberOf module:ControlFlow
* @method
* @category Control Flow
* @param {Array} tasks - An array of [async functions]{@link AsyncFunction}
* to run.
* Each function should complete with any number of `result` values.
* The `result` values will be passed as arguments, in order, to the next task.
* @param {Function} [callback] - An optional callback to run once all the
* functions have completed. This will be passed the results of the last task's
* callback. Invoked with (err, [results]).
* @returns {Promise} a promise, if a callback is omitted
* @example
*
* async.waterfall([
* function(callback) {
* callback(null, 'one', 'two');
* },
* function(arg1, arg2, callback) {
* // arg1 now equals 'one' and arg2 now equals 'two'
* callback(null, 'three');
* },
* function(arg1, callback) {
* // arg1 now equals 'three'
* callback(null, 'done');
* }
* ], function (err, result) {
* // result now equals 'done'
* });
*
* // Or, with named functions:
* async.waterfall([
* myFirstFunction,
* mySecondFunction,
* myLastFunction,
* ], function (err, result) {
* // result now equals 'done'
* });
* function myFirstFunction(callback) {
* callback(null, 'one', 'two');
* }
* function mySecondFunction(arg1, arg2, callback) {
* // arg1 now equals 'one' and arg2 now equals 'two'
* callback(null, 'three');
* }
* function myLastFunction(arg1, callback) {
* // arg1 now equals 'three'
* callback(null, 'done');
* }
*/
function waterfall(tasks, callback) {
callback = (0, _once2.default)(callback);
if (!Array.isArray(tasks)) return callback(new Error('First argument to waterfall must be an array of functions'));
if (!tasks.length) return callback();
var taskIndex = 0;
function nextTask(args) {
var task = (0, _wrapAsync2.default)(tasks[taskIndex++]);
task(...args, (0, _onlyOnce2.default)(next));
}
function next(err, ...args) {
if (err === false) return;
if (err || taskIndex === tasks.length) {
return callback(err, ...args);
}
nextTask(args);
}
nextTask([]);
}
exports.default = (0, _awaitify2.default)(waterfall);
module.exports = exports['default'];
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