Promise support

README.md

@@ -1,7 +1,7 @@
 Node.js: fs-extra
 =================
 
-`fs-extra` adds file system methods that aren't included in the native `fs` module. It is a drop in replacement for `fs`.
+`fs-extra` adds file system methods that aren't included in the native `fs` module and adds promise support to the `fs` methods. It should be a drop in replacement for `fs`.
 
 [![npm Package](https://img.shields.io/npm/v/fs-extra.svg?style=flat-square)](https://www.npmjs.org/package/fs-extra)
 [![build status](https://api.travis-ci.org/jprichardson/node-fs-extra.svg)](http://travis-ci.org/jprichardson/node-fs-extra)
@@ -30,7 +30,7 @@ Installation
 Usage
 -----
 
-`fs-extra` is a drop in replacement for native `fs`. All methods in `fs` are unmodified and attached to `fs-extra`.
+`fs-extra` is a drop in replacement for native `fs`. All methods in `fs` are attached to `fs-extra`. All `fs` methods return promises if the callback isn't passed.
 
 You don't ever need to include the original `fs` module again:
 
@@ -60,7 +60,7 @@ const fse = require('fs-extra')
 
 Sync vs Async
 -------------
-Most methods are async by default (they take a callback with an `Error` as first argument).
+Most methods are async by default. All async methods will return a promise if the callback isn't passed.
 
 Sync methods on the other hand will throw if an error occurs.
 
@@ -69,14 +69,23 @@ Example:
 ```js
 const fs = require('fs-extra')
 
+// Async with promises:
+fs.copy('/tmp/myfile', '/tmp/mynewfile')
+  .then(() => console.log('success!'))
+  .catch(err => {
+    // Handle error
+  })
+
+// Async with callbacks:
 fs.copy('/tmp/myfile', '/tmp/mynewfile', err => {
   if (err) return console.error(err)
-  console.log("success!")
-});
+  console.log('success!')
+})
 
+// Sync:
 try {
   fs.copySync('/tmp/myfile', '/tmp/mynewfile')
-  console.log("success!")
+  console.log('success!')
 } catch (err) {
   console.error(err)
 }
@@ -119,7 +128,7 @@ Methods
 - [writeJsonSync](docs/writeJson-sync.md)
 
 
-**NOTE:** You can still use the native Node.js methods. They are copied over to `fs-extra`.
+**NOTE:** You can still use the native Node.js methods. They are promisified and copied over to `fs-extra`.
 
 ### What happened to `walk()` and `walkSync()`?
 
@@ -129,24 +138,6 @@ They were removed from `fs-extra` in v2.0.0. If you need the functionality, `wal
 Third Party
 -----------
 
-### Promises
-
-Use [Bluebird](https://github.com/petkaantonov/bluebird). See https://github.com/petkaantonov/bluebird/blob/master/API.md#promisification. `fs-extra` is
-explicitly listed as supported.
-
-```js
-const Promise = require('bluebird')
-const fs = Promise.promisifyAll(require('fs-extra'))
-```
-
-Or you can use a dedicated package:
-
-- [`fs-extra-promise`](https://github.com/overlookmotel/fs-extra-promise) uses Bluebird.
-- [`fs-promise`](https://github.com/kevinbeaty/fs-promise) uses
-  [Any Promise](https://github.com/kevinbeaty/any-promise) and also covers
-  [`mz/fs`](https://github.com/normalize/mz/blob/master/fs.js).
-- [`fs-p`](https://github.com/grammarly/fs-p) - TypeScript-friendly promises implementation
-
 
 ### TypeScript
 

docs/copy.md

@@ -1,4 +1,4 @@
-# copy(src, dest, [options], callback)
+# copy(src, dest, [options, callback])
 
 Copy a file or directory. The directory can have contents. Like `cp -r`.
 
@@ -28,6 +28,15 @@ fs.copy('/tmp/mydir', '/tmp/mynewdir', err => {
 
   console.log('success!')
 }) // copies directory, even if it has subdirectories or files
+
+// Promise usage:
+fs.copy('/tmp/myfile', '/tmp/mynewfile')
+.then(() => {
+  console.log('success!')
+})
+.catch(err => {
+  // handle error
+})
 ```
 
 **Using filter function**

docs/emptyDir.md

@@ -18,4 +18,13 @@ fs.emptyDir('/tmp/some/dir', err => {
 
   console.log('success!')
 })
+
+// With promises
+fs.emptyDir('/tmp/some/dir')
+.then(() => {
+  console.log('success!')
+})
+.catch(err => {
+  // handle error
+})
 ```

docs/ensureDir.md

@@ -1,4 +1,4 @@
-# ensureDir(dir, callback)
+# ensureDir(dir, [callback])
 
 Ensures that the directory exists. If the directory structure does not exist, it is created. Like `mkdir -p`.
 
@@ -17,4 +17,13 @@ fs.ensureDir(dir, err => {
   console.log(err) // => null
   // dir has now been created, including the directory it is to be placed in
 })
+
+// With Promises:
+fs.ensureDir(dir)
+.then(() => {
+  console.log('success!')
+})
+.catch(err => {
+  // handle error
+})
 ```

docs/ensureFile.md

@@ -1,4 +1,4 @@
-# ensureFile(file, callback)
+# ensureFile(file, [callback])
 
 Ensures that the file exists. If the file that is requested to be created is in directories that do not exist, these directories are created. If the file already exists, it is **NOT MODIFIED**.
 
@@ -17,4 +17,13 @@ fs.ensureFile(file, err => {
   console.log(err) // => null
   // file has now been created, including the directory it is to be placed in
 })
+
+// With Promises:
+fs.ensureFile(file)
+.then(() => {
+  console.log('success!')
+})
+.catch(err => {
+  // handle error
+})
 ```

docs/ensureLink.md

@@ -1,4 +1,4 @@
-# ensureLink(srcpath, dstpath, callback)
+# ensureLink(srcpath, dstpath, [callback])
 
 Ensures that the link exists. If the directory structure does not exist, it is created.
 
@@ -17,4 +17,13 @@ fs.ensureLink(srcpath, dstpath, err => {
   console.log(err) // => null
   // link has now been created, including the directory it is to be placed in
 })
+
+// With Promises:
+fs.ensureLink(srcpath, dstpath)
+.then(() => {
+  console.log('success!')
+})
+.catch(err => {
+  // handle error
+})
 ```

docs/ensureSymlink.md

@@ -1,4 +1,4 @@
-# ensureSymlink(srcpath, dstpath, [type], callback)
+# ensureSymlink(srcpath, dstpath, [type, callback])
 
 Ensures that the symlink exists. If the directory structure does not exist, it is created.
 
@@ -18,4 +18,13 @@ fs.ensureSymlink(srcpath, dstpath, err => {
   console.log(err) // => null
   // symlink has now been created, including the directory it is to be placed in
 })
+
+// With Promises:
+fs.ensureSymlink(srcpath, dstpath)
+.then(() => {
+  console.log('success!')
+})
+.catch(err => {
+  // handle error
+})
 ```

docs/move.md

@@ -1,4 +1,4 @@
-# move(src, dest, [options], callback)
+# move(src, dest, [options, callback])
 
 Moves a file or directory, even across devices.
 
@@ -18,6 +18,14 @@ fs.move('/tmp/somefile', '/tmp/does/not/exist/yet/somefile', err => {
 
   console.log('success!')
 })
+
+fs.move('/tmp/somefile', '/tmp/does/not/exist/yet/somefile')
+.then(() => {
+  console.log('success!')
+})
+.catch(err => {
+  // handle error
+})
 ```
 
 **Using `overwrite` option**

docs/outputFile.md

@@ -1,4 +1,4 @@
-# outputFile(file, data, [options], callback)
+# outputFile(file, data, [options, callback])
 
 Almost the same as `writeFile` (i.e. it [overwrites](http://pages.citebite.com/v2o5n8l2f5reb)), except that if the parent directory does not exist, it's created. `file` must be a file path (a buffer or a file descriptor is not allowed). `options` are what you'd pass to [`fs.writeFile()`](https://nodejs.org/api/fs.html#fs_fs_writefile_file_data_options_callback).
 
@@ -20,4 +20,14 @@ fs.outputFile(file, 'hello!', err => {
     console.log(data) // => hello!
   })
 })
+
+// With Promises:
+fs.outputFile(file, 'hello!')
+.then(() => fs.readFile(file, 'utf8'))
+.then(data => {
+  console.log(data) // => hello!
+})
+.catch(err => {
+  // handle error
+})
 ```

docs/outputJson.md

@@ -1,4 +1,4 @@
-# outputJson(file, object, [options], callback)
+# outputJson(file, object, [options, callback])
 
 Almost the same as [`writeJson`](writeJson.md), except that if the directory does not exist, it's created.
 `options` are what you'd pass to [`jsonFile.writeFile()`](https://github.com/jprichardson/node-jsonfile#writefilefilename-options-callback).
@@ -23,4 +23,14 @@ fs.outputJson(file, {name: 'JP'}, err => {
     console.log(data.name) // => JP
   })
 })
+
+// With Promises:
+fs.outputJson(file, {name: 'JP'})
+.then(() => fs.readJson(file))
+.then(data => {
+  console.log(data.name) // => JP
+})
+.catch(err => {
+  // handle error
+})
 ```

docs/readJson.md

@@ -1,4 +1,4 @@
-# readJson(file, [options], callback)
+# readJson(file, [options, callback])
 
 Reads a JSON file and then parses it into an object. `options` are the same
 that you'd pass to [`jsonFile.readFile`](https://github.com/jprichardson/node-jsonfile#readfilefilename-options-callback).
@@ -16,9 +16,18 @@ const fs = require('fs-extra')
 
 fs.readJson('./package.json', (err, packageObj) => {
   if (err) console.error(err)
-  
+
   console.log(packageObj.version) // => 0.1.3
 })
+
+// Promise Usage
+fs.readJson('./package.json')
+.then(packageObj => {
+  console.log(packageObj.version) // => 0.1.3
+})
+.catch(err => {
+  // handle error
+})
 ```
 
 ---
@@ -37,4 +46,13 @@ fs.readJson(file, { throws: false }, (err, obj) => {
 
   console.log(obj) // => null
 })
+
+// Promise Usage
+fs.readJson(file, { throws: false })
+.then(obj => {
+  console.log(obj) // => null
+})
+.catch(err => {
+  // Not called
+})
 ```

docs/remove.md

@@ -1,4 +1,4 @@
-# remove(path, callback)
+# remove(path, [callback])
 
 Removes a file or directory. The directory can have contents. Like `rm -rf`.
 
@@ -22,4 +22,13 @@ fs.remove('/home/jprichardson', err => {
 
   console.log('success!') // I just deleted my entire HOME directory.
 })
+
+// Promise Usage
+fs.remove('/tmp/myfile')
+.then(() => {
+  console.log('success!')
+})
+.catch(err => {
+  // handle error
+})
 ```

docs/writeJson.md

@@ -1,4 +1,4 @@
-# writeJson(file, object, [options], callback)
+# writeJson(file, object, [options, callback])
 
 Writes an object to a JSON file. `options` are the same that
 you'd pass to [`jsonFile.writeFile()`](https://github.com/jprichardson/node-jsonfile#writefilefilename-options-callback).
@@ -20,6 +20,15 @@ fs.writeJson('./package.json', {name: 'fs-extra'}, err => {
 
   console.log('success!')
 })
+
+// With Promises
+fs.writeJson('./package.json', {name: 'fs-extra'})
+.then(() => {
+  console.log('success!')
+})
+.catch(err => {
+  // handle error
+})
 ```
 
 ---

lib/__tests__/promise.test.js

@@ -0,0 +1,29 @@
+'use strict'
+
+/* eslint-env mocha */
+
+const fse = require('..')
+
+const methods = [
+  'copy',
+  'emptyDir',
+  'ensureFile',
+  'ensureDir',
+  'ensureLink',
+  'ensureSymlink',
+  'mkdirs',
+  'move',
+  'readJson',
+  'readJSON',
+  'remove',
+  'writeJson',
+  'writeJSON'
+]
+
+describe('promise support', () => {
+  methods.forEach(method => {
+    it(method, done => {
+      fse[method]().catch(() => done())
+    })
+  })
+})

lib/copy/index.js

@@ -1,3 +1,4 @@
+const u = require('universalify').fromCallback
 module.exports = {
-  copy: require('./copy')
+  copy: u(require('./copy'))
 }