import noop from 'lodash/noop'; import slice from './internal/slice'; import onlyOnce from './internal/onlyOnce'; import wrapAsync from './internal/wrapAsync'; /** * 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 {Function} test - synchronous truth test to perform after each * execution of `iteratee`. Invoked with any non-error callback results 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]); */ export default function doWhilst(iteratee, test, callback) { callback = onlyOnce(callback || noop); var _iteratee = wrapAsync(iteratee); var next = function(err/*, ...args*/) { if (err) return callback(err); var args = slice(arguments, 1); if (test.apply(this, args)) return _iteratee(next); callback.apply(null, [null].concat(args)); }; _iteratee(next); }