; | |
Object.defineProperty(exports, "__esModule", { | |
value: true | |
}); | |
var _createTester = require('./internal/createTester.js'); | |
var _createTester2 = _interopRequireDefault(_createTester); | |
var _eachOf = require('./eachOf.js'); | |
var _eachOf2 = _interopRequireDefault(_eachOf); | |
var _awaitify = require('./internal/awaitify.js'); | |
var _awaitify2 = _interopRequireDefault(_awaitify); | |
function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; } | |
/** | |
* Returns the first value in `coll` that passes an async truth test. The | |
* `iteratee` is applied in parallel, meaning the first iteratee to return | |
* `true` will fire the detect `callback` with that result. That means the | |
* result might not be the first item in the original `coll` (in terms of order) | |
* that passes the test. | |
* If order within the original `coll` is important, then look at | |
* [`detectSeries`]{@link module:Collections.detectSeries}. | |
* | |
* @name detect | |
* @static | |
* @memberOf module:Collections | |
* @method | |
* @alias find | |
* @category Collections | |
* @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over. | |
* @param {AsyncFunction} iteratee - A truth test to apply to each item in `coll`. | |
* The iteratee must complete with a boolean value as its result. | |
* Invoked with (item, callback). | |
* @param {Function} [callback] - A callback which is called as soon as any | |
* iteratee returns `true`, or after all the `iteratee` functions have finished. | |
* Result will be the first item in the array that passes the truth test | |
* (iteratee) or the value `undefined` if none passed. Invoked with | |
* (err, result). | |
* @returns {Promise} a promise, if a callback is omitted | |
* @example | |
* | |
* // dir1 is a directory that contains file1.txt, file2.txt | |
* // dir2 is a directory that contains file3.txt, file4.txt | |
* // dir3 is a directory that contains file5.txt | |
* | |
* // asynchronous function that checks if a file exists | |
* function fileExists(file, callback) { | |
* fs.access(file, fs.constants.F_OK, (err) => { | |
* callback(null, !err); | |
* }); | |
* } | |
* | |
* async.detect(['file3.txt','file2.txt','dir1/file1.txt'], fileExists, | |
* function(err, result) { | |
* console.log(result); | |
* // dir1/file1.txt | |
* // result now equals the first file in the list that exists | |
* } | |
*); | |
* | |
* // Using Promises | |
* async.detect(['file3.txt','file2.txt','dir1/file1.txt'], fileExists) | |
* .then(result => { | |
* console.log(result); | |
* // dir1/file1.txt | |
* // result now equals the first file in the list that exists | |
* }).catch(err => { | |
* console.log(err); | |
* }); | |
* | |
* // Using async/await | |
* async () => { | |
* try { | |
* let result = await async.detect(['file3.txt','file2.txt','dir1/file1.txt'], fileExists); | |
* console.log(result); | |
* // dir1/file1.txt | |
* // result now equals the file in the list that exists | |
* } | |
* catch (err) { | |
* console.log(err); | |
* } | |
* } | |
* | |
*/ | |
function detect(coll, iteratee, callback) { | |
return (0, _createTester2.default)(bool => bool, (res, item) => item)(_eachOf2.default, coll, iteratee, callback); | |
} | |
exports.default = (0, _awaitify2.default)(detect, 3); | |
module.exports = exports.default; |