--- /dev/null
+'use strict';
+
+Object.defineProperty(exports, "__esModule", {
+ value: true
+});
+exports.default = doDuring;
+
+var _noop = require('lodash/noop');
+
+var _noop2 = _interopRequireDefault(_noop);
+
+var _rest = require('./internal/rest');
+
+var _rest2 = _interopRequireDefault(_rest);
+
+var _onlyOnce = require('./internal/onlyOnce');
+
+var _onlyOnce2 = _interopRequireDefault(_onlyOnce);
+
+function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
+
+/**
+ * The post-check version of [`during`]{@link module:ControlFlow.during}. To reflect the difference in
+ * the order of operations, the arguments `test` and `fn` are switched.
+ *
+ * Also a version of [`doWhilst`]{@link module:ControlFlow.doWhilst} with asynchronous `test` function.
+ * @name doDuring
+ * @static
+ * @memberOf module:ControlFlow
+ * @method
+ * @see [async.during]{@link module:ControlFlow.during}
+ * @category Control Flow
+ * @param {Function} fn - A function which is called each time `test` passes.
+ * The function is passed a `callback(err)`, which must be called once it has
+ * completed with an optional `err` argument. Invoked with (callback).
+ * @param {Function} test - asynchronous truth test to perform before each
+ * execution of `fn`. Invoked with (...args, callback), where `...args` are the
+ * non-error args from the previous callback of `fn`.
+ * @param {Function} [callback] - A callback which is called after the test
+ * function has failed and repeated execution of `fn` has stopped. `callback`
+ * will be passed an error if one occured, otherwise `null`.
+ */
+function doDuring(fn, test, callback) {
+ callback = (0, _onlyOnce2.default)(callback || _noop2.default);
+
+ var next = (0, _rest2.default)(function (err, args) {
+ if (err) return callback(err);
+ args.push(check);
+ test.apply(this, args);
+ });
+
+ function check(err, truth) {
+ if (err) return callback(err);
+ if (!truth) return callback(null);
+ fn(next);
+ }
+
+ check(null, true);
+}
+module.exports = exports['default'];
\ No newline at end of file