io-extra

io-extra

Library to simplify file system access with promises in Node.js

Installation

npm install --save io-extra

Implementation

io-extra is a thin wrapper on top of fs-promise simplifying the file and directory access with easy to use and well documented functions.

• All functions returns ES2015 (ES6) compatible promises.
• Use any-promise to register your preferred Promise implementation. (defaults to the Node builtin global Promise)

Usage

const io = require('io-extra');

io.file.exists('/tmp/myfile').then((exists) => {
    if (exists) {
        console.log(`File exists`);
    }
}

File Methods | Directory Methods

File

• path
• exists
• create
• remove
• rename
• copy
• read
• write

resolve fullpath

path(file)

Returnes the resolved full path of a file. The file must exist.

Example:

const io = require('io-extra');

io.file.path('/tmp/myfile').then((file) => console.log('fullpath: ' + file));
// returns c:\tmp\myfile on Windows operating systems

file exists

exists(file)

Check if a file exists. Promise returns true or false whether the file exists or not.

Example:

const io = require('io-extra');

io.file.exists('/tmp/myfile').then((exists) => console.log('file exists: ' + exists));

create file

create(file)

Creates a file if it doesn't already exist. If the file is in directories that do not exist, these directories are created. Promise returns the full path of the created file.

Example:

const io = require('io-extra');

io.file.create('/tmp/myfile').then((file) => console.log('file ' + file + ' created.'));

remove file

remove(file)

Removes a file if it exists. Empty promise is returned.

Alias: delete()

Example:

const io = require('io-extra');

io.file.remove('/tmp/myfile').then(() => console.log('file removed.'));

rename file

rename(src, dest, [overwrite])

Renames a file. Promise returns the full path of the destination file.

• overwrite: (optional boolean) overwrite existing file, default is true.

Example:

const io = require('io-extra');

io.file.rename('/tmp/myfile', '/tmp/myfile.bak')
    .then((file) => console.log('file renamed to ' + file));

copy file

copy(src, dest, [overwrite], [preserveTimestamps])

Copies a file. If the destination file is in directories that do not exist, these directories are created. Promise returns the full path of the destination file.

• overwrite: (optional boolean) overwrite existing file, default is true.

• preserveTimestamps : (optional boolean) set last modification and access time to the original source file, default is false.

Example:

const io = require('io-extra');

io.file.copy('/tmp/myfile', '/tmp/dest/myfile.bak')
    .then((file) => console.log('file copied to ' + file));

read file

read(file, [encoding])

Reads the entire contents of a file. Promise contains the text of the file.

• encoding: (optional string) specifies the type of encoding to read the file. Possible encodings are 'ascii', 'utf8', and 'base64'. If no encoding is provided, the default is utf8.

Example:

const io = require('io-extra');

io.file.read('/tmp/myfile').then((text) => console.log(text));

write file

write(file, data, [encoding])

Writes data to a file, replacing the file if it already exists. If the parent directory does not exist, it's created. Empty promise is returned.

• file: (string) filepath of the file to write to.

• data: (string or buffer) the data you want to write to the file.

• encoding: (optional string) the encoding of the data. Possible encodings are 'ascii', 'utf8', and 'base64'. If no encoding provided, then 'utf8' is assumed.

Example:

const io = require('io-extra');

io.file.write('/tmp/myfile', 'io-extra is easy!')
    .then(() => console.log('file written.'));

Directory

• path
• exists
• create
• remove
• rename
• copy
• clean

resolve directory fullpath

path(directory)

Returnes the resolved full path of a directory. The directory must exist.

Example:

const io = require('io-extra');

io.directory.path('/tmp').then((dir) => console.log('fullpath: ' + dir));
// returns c:\tmp on Windows operating systems

directory exists

exists(directory)

Check if a directory exists. Promise returns true or false whether the directory exists or not.

Example:

const io = require('io-extra');

io.directory.exists('/tmp').then((exists) => console.log('directory exists: ' + exists));

create directory

create(directory)

Creates a directory if it doesn't already exist. If the parent directory does not exist, it is created. Promise returns the full path of the created directory.

Example:

const io = require('io-extra');

io.directory.create('/tmp').then((dir) => console.log('directory ' + dir + ' created.'));

remove directory

remove(directory)

Removes a directory if it exists. Empty promise is returned.

Alias: delete()

Example:

const io = require('io-extra');

io.directory.remove('/tmp').then(() => console.log('directory removed.'));

rename directory

rename(src, dest, [overwrite])

Renames a directory. Promise returns the full path of the destination directory.

• overwrite: (optional boolean) overwrite existing directory, default is true.

Example:

const io = require('io-extra');

io.directory.rename('/tmp', '/bak')
    .then((directory) => console.log('directory renamed to ' + directory));

copy directory

copy(src, dest, [options])

Copies a directory. If the destination directory is in directories that do not exist, these directories are created. Promise returns the full path of the destination directory.

• options: (optional object)

  • overwrite: (boolean) overwrite existing directories and files, default is true.

  • dereference: (boolean) dereference symlinks, default is false.

  • preserveTimestamps: (boolean) set last modification and access time to the original source files, default is false.

  • filter: (function or RegExp) filter copied files. If function, return true to include, false to exclude. If RegExp, same as function, where filter is filter.test.

Example:

const io = require('io-extra');

io.directory.copy('/tmp', '/temp')
    .then((directory) => console.log('directory copied to: ' + directory));

clean directory

clean(directory)

Cleans directory contents. If the directory does not exist, it is created. The directory itself is not deleted. Empty promise is returned.

Alias: empty()

Example:

const io = require('io-extra');

io.directory.clean('/tmp').then(() => console.log('directory cleaned.'));