doWhilst.js

'use strict';

Object.defineProperty(exports, "__esModule", {
    value: true
});

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 }; }

/**
 * The post-check version of [`whilst`]{@link module:ControlFlow.whilst}. To reflect the difference in
 * the order of operations, the arguments `test` and `iteratee` are switched.
 *
 * `doWhilst` is to `whilst` as `do while` is to `while` in plain JavaScript.
 *
 * @name doWhilst
 * @static
 * @memberOf module:ControlFlow
 * @method
 * @see [async.whilst]{@link module:ControlFlow.whilst}
 * @category Control Flow
 * @param {AsyncFunction} iteratee - A function which is called each time `test`
 * passes. Invoked with (callback).
 * @param {AsyncFunction} test - asynchronous truth test to perform after each
 * execution of `iteratee`. Invoked with (...args, callback), where `...args` are the
 * non-error args from the previous callback of `iteratee`.
 * @param {Function} [callback] - A callback which is called after the test
 * function has failed and repeated execution of `iteratee` has stopped.
 * `callback` will be passed an error and any arguments passed to the final
 * `iteratee`'s callback. Invoked with (err, [results]);
 * @returns {Promise} a promise, if no callback is passed
 */
function doWhilst(iteratee, test, callback) {
    callback = (0, _onlyOnce2.default)(callback);
    var _fn = (0, _wrapAsync2.default)(iteratee);
    var _test = (0, _wrapAsync2.default)(test);
    var results;

    function next(err, ...args) {
        if (err) return callback(err);
        if (err === false) return;
        results = args;
        _test(...args, check);
    }

    function check(err, truth) {
        if (err) return callback(err);
        if (err === false) return;
        if (!truth) return callback(null, ...results);
        _fn(next);
    }

    return check(null, true);
}

exports.default = (0, _awaitify2.default)(doWhilst, 3);
module.exports = exports['default'];