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author | Minteck <contact@minteck.org> | 2022-11-28 17:14:38 +0100 |
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committer | Minteck <contact@minteck.org> | 2022-11-28 17:14:38 +0100 |
commit | 18efd30a263ec0d79a26a82cbd8c90c9f81056b7 (patch) | |
tree | aea01bf3506dda706719fc68eb37b77ed9ef3fe8 /node_modules/async/transform.js | |
download | autoreport-18efd30a263ec0d79a26a82cbd8c90c9f81056b7.tar.gz autoreport-18efd30a263ec0d79a26a82cbd8c90c9f81056b7.tar.bz2 autoreport-18efd30a263ec0d79a26a82cbd8c90c9f81056b7.zip |
Diffstat (limited to 'node_modules/async/transform.js')
-rw-r--r-- | node_modules/async/transform.js | 173 |
1 files changed, 173 insertions, 0 deletions
diff --git a/node_modules/async/transform.js b/node_modules/async/transform.js new file mode 100644 index 0000000..75b754e --- /dev/null +++ b/node_modules/async/transform.js @@ -0,0 +1,173 @@ +'use strict'; + +Object.defineProperty(exports, "__esModule", { + value: true +}); +exports.default = transform; + +var _eachOf = require('./eachOf.js'); + +var _eachOf2 = _interopRequireDefault(_eachOf); + +var _once = require('./internal/once.js'); + +var _once2 = _interopRequireDefault(_once); + +var _wrapAsync = require('./internal/wrapAsync.js'); + +var _wrapAsync2 = _interopRequireDefault(_wrapAsync); + +var _promiseCallback = require('./internal/promiseCallback.js'); + +function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; } + +/** + * A relative of `reduce`. Takes an Object or Array, and iterates over each + * element in parallel, each step potentially mutating an `accumulator` value. + * The type of the accumulator defaults to the type of collection passed in. + * + * @name transform + * @static + * @memberOf module:Collections + * @method + * @category Collection + * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over. + * @param {*} [accumulator] - The initial state of the transform. If omitted, + * it will default to an empty Object or Array, depending on the type of `coll` + * @param {AsyncFunction} iteratee - A function applied to each item in the + * collection that potentially modifies the accumulator. + * Invoked with (accumulator, item, key, callback). + * @param {Function} [callback] - A callback which is called after all the + * `iteratee` functions have finished. Result is the transformed accumulator. + * Invoked with (err, result). + * @returns {Promise} a promise, if no callback provided + * @example + * + * // file1.txt is a file that is 1000 bytes in size + * // file2.txt is a file that is 2000 bytes in size + * // file3.txt is a file that is 3000 bytes in size + * + * // helper function that returns human-readable size format from bytes + * function formatBytes(bytes, decimals = 2) { + * // implementation not included for brevity + * return humanReadbleFilesize; + * } + * + * const fileList = ['file1.txt','file2.txt','file3.txt']; + * + * // asynchronous function that returns the file size, transformed to human-readable format + * // e.g. 1024 bytes = 1KB, 1234 bytes = 1.21 KB, 1048576 bytes = 1MB, etc. + * function transformFileSize(acc, value, key, callback) { + * fs.stat(value, function(err, stat) { + * if (err) { + * return callback(err); + * } + * acc[key] = formatBytes(stat.size); + * callback(null); + * }); + * } + * + * // Using callbacks + * async.transform(fileList, transformFileSize, function(err, result) { + * if(err) { + * console.log(err); + * } else { + * console.log(result); + * // [ '1000 Bytes', '1.95 KB', '2.93 KB' ] + * } + * }); + * + * // Using Promises + * async.transform(fileList, transformFileSize) + * .then(result => { + * console.log(result); + * // [ '1000 Bytes', '1.95 KB', '2.93 KB' ] + * }).catch(err => { + * console.log(err); + * }); + * + * // Using async/await + * (async () => { + * try { + * let result = await async.transform(fileList, transformFileSize); + * console.log(result); + * // [ '1000 Bytes', '1.95 KB', '2.93 KB' ] + * } + * catch (err) { + * console.log(err); + * } + * })(); + * + * @example + * + * // file1.txt is a file that is 1000 bytes in size + * // file2.txt is a file that is 2000 bytes in size + * // file3.txt is a file that is 3000 bytes in size + * + * // helper function that returns human-readable size format from bytes + * function formatBytes(bytes, decimals = 2) { + * // implementation not included for brevity + * return humanReadbleFilesize; + * } + * + * const fileMap = { f1: 'file1.txt', f2: 'file2.txt', f3: 'file3.txt' }; + * + * // asynchronous function that returns the file size, transformed to human-readable format + * // e.g. 1024 bytes = 1KB, 1234 bytes = 1.21 KB, 1048576 bytes = 1MB, etc. + * function transformFileSize(acc, value, key, callback) { + * fs.stat(value, function(err, stat) { + * if (err) { + * return callback(err); + * } + * acc[key] = formatBytes(stat.size); + * callback(null); + * }); + * } + * + * // Using callbacks + * async.transform(fileMap, transformFileSize, function(err, result) { + * if(err) { + * console.log(err); + * } else { + * console.log(result); + * // { f1: '1000 Bytes', f2: '1.95 KB', f3: '2.93 KB' } + * } + * }); + * + * // Using Promises + * async.transform(fileMap, transformFileSize) + * .then(result => { + * console.log(result); + * // { f1: '1000 Bytes', f2: '1.95 KB', f3: '2.93 KB' } + * }).catch(err => { + * console.log(err); + * }); + * + * // Using async/await + * async () => { + * try { + * let result = await async.transform(fileMap, transformFileSize); + * console.log(result); + * // { f1: '1000 Bytes', f2: '1.95 KB', f3: '2.93 KB' } + * } + * catch (err) { + * console.log(err); + * } + * } + * + */ +function transform(coll, accumulator, iteratee, callback) { + if (arguments.length <= 3 && typeof accumulator === 'function') { + callback = iteratee; + iteratee = accumulator; + accumulator = Array.isArray(coll) ? [] : {}; + } + callback = (0, _once2.default)(callback || (0, _promiseCallback.promiseCallback)()); + var _iteratee = (0, _wrapAsync2.default)(iteratee); + + (0, _eachOf2.default)(coll, (v, k, cb) => { + _iteratee(accumulator, v, k, cb); + }, err => callback(err, accumulator)); + return callback[_promiseCallback.PROMISE_SYMBOL]; +} +module.exports = exports['default'];
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