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author | Roman Lorenzo Balayan <roman.balayan@gmail.com> | 2021-08-06 06:58:10 +0800 |
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committer | GitHub <noreply@github.com> | 2021-08-05 15:58:10 -0700 |
commit | 159a119fbb1a585c61f33b4b3b5036f5d332ebbb (patch) | |
tree | bbf78b2e8899c412ceede4a705d45368f61b51bf /lib/sortBy.js | |
parent | 89255fe326050e80ce5394a9c00e11e9be8b1005 (diff) | |
download | async-159a119fbb1a585c61f33b4b3b5036f5d332ebbb.tar.gz |
Enhance examples for Collections methods. (#1726)
* Enhance examples for Collections methods.
* Update collection example code, avoiding usage of IIFE on async/await examples
* Convert examples on async.auto, async.series, and async.parallel to samples using Promises and async/await
Co-authored-by: Roman Balayan <roman.balayan@paymaya.com>
Diffstat (limited to 'lib/sortBy.js')
-rw-r--r-- | lib/sortBy.js | 134 |
1 files changed, 118 insertions, 16 deletions
diff --git a/lib/sortBy.js b/lib/sortBy.js index 4477677..7a1b9fb 100644 --- a/lib/sortBy.js +++ b/lib/sortBy.js @@ -24,31 +24,133 @@ import awaitify from './internal/awaitify' * @returns {Promise} a promise, if no callback passed * @example * - * async.sortBy(['file1','file2','file3'], function(file, callback) { - * fs.stat(file, function(err, stats) { - * callback(err, stats.mtime); + * // bigfile.txt is a file that is 251100 bytes in size + * // mediumfile.txt is a file that is 11000 bytes in size + * // smallfile.txt is a file that is 121 bytes in size + * + * // asynchronous function that returns the file size in bytes + * function getFileSizeInBytes(file, callback) { + * fs.stat(file, function(err, stat) { + * if (err) { + * return callback(err); + * } + * callback(null, stat.size); * }); - * }, function(err, results) { - * // results is now the original array of files sorted by - * // modified date - * }); + * } + * + * // Using callbacks + * async.sortBy(['mediumfile.txt','smallfile.txt','bigfile.txt'], getFileSizeInBytes, + * function(err, results) { + * if (err) { + * console.log(err); + * } else { + * console.log(results); + * // results is now the original array of files sorted by + * // file size (ascending by default), e.g. + * // [ 'smallfile.txt', 'mediumfile.txt', 'bigfile.txt'] + * } + * } + * ); * * // By modifying the callback parameter the * // sorting order can be influenced: * * // ascending order - * async.sortBy([1,9,3,5], function(x, callback) { - * callback(null, x); - * }, function(err,result) { - * // result callback - * }); + * async.sortBy(['mediumfile.txt','smallfile.txt','bigfile.txt'], function(file, callback) { + * getFileSizeInBytes(file, function(getFileSizeErr, fileSize) { + * if (getFileSizeErr) return callback(getFileSizeErr); + * callback(null, fileSize); + * }); + * }, function(err, results) { + * if (err) { + * console.log(err); + * } else { + * console.log(results); + * // results is now the original array of files sorted by + * // file size (ascending by default), e.g. + * // [ 'smallfile.txt', 'mediumfile.txt', 'bigfile.txt'] + * } + * } + * ); * * // descending order - * async.sortBy([1,9,3,5], function(x, callback) { - * callback(null, x*-1); //<- x*-1 instead of x, turns the order around - * }, function(err,result) { - * // result callback + * async.sortBy(['bigfile.txt','mediumfile.txt','smallfile.txt'], function(file, callback) { + * getFileSizeInBytes(file, function(getFileSizeErr, fileSize) { + * if (getFileSizeErr) { + * return callback(getFileSizeErr); + * } + * callback(null, fileSize * -1); + * }); + * }, function(err, results) { + * if (err) { + * console.log(err); + * } else { + * console.log(results); + * // results is now the original array of files sorted by + * // file size (ascending by default), e.g. + * // [ 'bigfile.txt', 'mediumfile.txt', 'smallfile.txt'] + * } + * } + * ); + * + * // Error handling + * async.sortBy(['mediumfile.txt','smallfile.txt','missingfile.txt'], getFileSizeInBytes, + * function(err, results) { + * if (err) { + * console.log(err); + * // [ Error: ENOENT: no such file or directory ] + * } else { + * console.log(results); + * } + * } + * ); + * + * // Using Promises + * async.sortBy(['mediumfile.txt','smallfile.txt','bigfile.txt'], getFileSizeInBytes) + * .then( results => { + * console.log(results); + * // results is now the original array of files sorted by + * // file size (ascending by default), e.g. + * // [ 'smallfile.txt', 'mediumfile.txt', 'bigfile.txt'] + * }).catch( err => { + * console.log(err); * }); + * + * // Error handling + * async.sortBy(['mediumfile.txt','smallfile.txt','missingfile.txt'], getFileSizeInBytes) + * .then( results => { + * console.log(results); + * }).catch( err => { + * console.log(err); + * // [ Error: ENOENT: no such file or directory ] + * }); + * + * // Using async/await + * (async () => { + * try { + * let results = await async.sortBy(['bigfile.txt','mediumfile.txt','smallfile.txt'], getFileSizeInBytes); + * console.log(results); + * // results is now the original array of files sorted by + * // file size (ascending by default), e.g. + * // [ 'smallfile.txt', 'mediumfile.txt', 'bigfile.txt'] + * } + * catch (err) { + * console.log(err); + * } + * })(); + * + * // Error handling + * async () => { + * try { + * let results = await async.sortBy(['missingfile.txt','mediumfile.txt','smallfile.txt'], getFileSizeInBytes); + * console.log(results); + * } + * catch (err) { + * console.log(err); + * // [ Error: ENOENT: no such file or directory ] + * } + * } + * */ function sortBy (coll, iteratee, callback) { var _iteratee = wrapAsync(iteratee); |