'use strict';
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Object.defineProperty(exports, "__esModule", {
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value: true
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});
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exports.default = autoInject;
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var _auto = require('./auto');
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var _auto2 = _interopRequireDefault(_auto);
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var _baseForOwn = require('lodash/_baseForOwn');
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var _baseForOwn2 = _interopRequireDefault(_baseForOwn);
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var _arrayMap = require('lodash/_arrayMap');
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var _arrayMap2 = _interopRequireDefault(_arrayMap);
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var _isArray = require('lodash/isArray');
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var _isArray2 = _interopRequireDefault(_isArray);
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var _trim = require('lodash/trim');
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var _trim2 = _interopRequireDefault(_trim);
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var _wrapAsync = require('./internal/wrapAsync');
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var _wrapAsync2 = _interopRequireDefault(_wrapAsync);
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function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
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var FN_ARGS = /^(?:async\s+)?(function)?\s*[^\(]*\(\s*([^\)]*)\)/m;
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var FN_ARG_SPLIT = /,/;
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var FN_ARG = /(=.+)?(\s*)$/;
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var STRIP_COMMENTS = /((\/\/.*$)|(\/\*[\s\S]*?\*\/))/mg;
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function parseParams(func) {
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func = func.toString().replace(STRIP_COMMENTS, '');
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func = func.match(FN_ARGS)[2].replace(' ', '');
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func = func ? func.split(FN_ARG_SPLIT) : [];
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func = func.map(function (arg) {
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return (0, _trim2.default)(arg.replace(FN_ARG, ''));
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});
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return func;
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}
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/**
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* A dependency-injected version of the [async.auto]{@link module:ControlFlow.auto} function. Dependent
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* tasks are specified as parameters to the function, after the usual callback
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* parameter, with the parameter names matching the names of the tasks it
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* depends on. This can provide even more readable task graphs which can be
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* easier to maintain.
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*
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* If a final callback is specified, the task results are similarly injected,
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* specified as named parameters after the initial error parameter.
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*
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* The autoInject function is purely syntactic sugar and its semantics are
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* otherwise equivalent to [async.auto]{@link module:ControlFlow.auto}.
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*
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* @name autoInject
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* @static
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* @memberOf module:ControlFlow
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* @method
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* @see [async.auto]{@link module:ControlFlow.auto}
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* @category Control Flow
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* @param {Object} tasks - An object, each of whose properties is an {@link AsyncFunction} of
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* the form 'func([dependencies...], callback). The object's key of a property
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* serves as the name of the task defined by that property, i.e. can be used
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* when specifying requirements for other tasks.
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* * The `callback` parameter is a `callback(err, result)` which must be called
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* when finished, passing an `error` (which can be `null`) and the result of
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* the function's execution. The remaining parameters name other tasks on
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* which the task is dependent, and the results from those tasks are the
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* arguments of those parameters.
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* @param {Function} [callback] - An optional callback which is called when all
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* the tasks have been completed. It receives the `err` argument if any `tasks`
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* pass an error to their callback, and a `results` object with any completed
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* task results, similar to `auto`.
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* @example
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*
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* // The example from `auto` can be rewritten as follows:
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* async.autoInject({
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* get_data: function(callback) {
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* // async code to get some data
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* callback(null, 'data', 'converted to array');
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* },
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* make_folder: function(callback) {
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* // async code to create a directory to store a file in
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* // this is run at the same time as getting the data
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* callback(null, 'folder');
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* },
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* write_file: function(get_data, make_folder, callback) {
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* // once there is some data and the directory exists,
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* // write the data to a file in the directory
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* callback(null, 'filename');
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* },
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* email_link: function(write_file, callback) {
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* // once the file is written let's email a link to it...
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* // write_file contains the filename returned by write_file.
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* callback(null, {'file':write_file, 'email':'user@example.com'});
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* }
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* }, function(err, results) {
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* console.log('err = ', err);
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* console.log('email_link = ', results.email_link);
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* });
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*
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* // If you are using a JS minifier that mangles parameter names, `autoInject`
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* // will not work with plain functions, since the parameter names will be
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* // collapsed to a single letter identifier. To work around this, you can
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* // explicitly specify the names of the parameters your task function needs
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* // in an array, similar to Angular.js dependency injection.
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*
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* // This still has an advantage over plain `auto`, since the results a task
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* // depends on are still spread into arguments.
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* async.autoInject({
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* //...
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* write_file: ['get_data', 'make_folder', function(get_data, make_folder, callback) {
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* callback(null, 'filename');
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* }],
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* email_link: ['write_file', function(write_file, callback) {
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* callback(null, {'file':write_file, 'email':'user@example.com'});
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* }]
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* //...
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* }, function(err, results) {
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* console.log('err = ', err);
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* console.log('email_link = ', results.email_link);
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* });
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*/
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function autoInject(tasks, callback) {
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var newTasks = {};
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(0, _baseForOwn2.default)(tasks, function (taskFn, key) {
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var params;
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var fnIsAsync = (0, _wrapAsync.isAsync)(taskFn);
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var hasNoDeps = !fnIsAsync && taskFn.length === 1 || fnIsAsync && taskFn.length === 0;
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if ((0, _isArray2.default)(taskFn)) {
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params = taskFn.slice(0, -1);
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taskFn = taskFn[taskFn.length - 1];
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newTasks[key] = params.concat(params.length > 0 ? newTask : taskFn);
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} else if (hasNoDeps) {
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// no dependencies, use the function as-is
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newTasks[key] = taskFn;
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} else {
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params = parseParams(taskFn);
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if (taskFn.length === 0 && !fnIsAsync && params.length === 0) {
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throw new Error("autoInject task functions require explicit parameters.");
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}
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// remove callback param
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if (!fnIsAsync) params.pop();
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newTasks[key] = params.concat(newTask);
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}
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function newTask(results, taskCb) {
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var newArgs = (0, _arrayMap2.default)(params, function (name) {
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return results[name];
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});
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newArgs.push(taskCb);
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(0, _wrapAsync2.default)(taskFn).apply(null, newArgs);
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}
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});
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(0, _auto2.default)(newTasks, callback);
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}
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module.exports = exports['default'];
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