fs-jetpack

fs-jetpack

Node's fs library API is very low level, and because of that painful to use. We need higher layer of abstraction over it. That's what fs-jetpack aspires to be.

Jump to API Docs

Installation

npm install fs-jetpack

Usage

var jetpack = requite('fs-jetpack');

#What's cool about jetpack?

Promises instead of callbacks

API has the same set of synchronous and asynchronous methods. All async methods are promise based.

Commonly used naming convention in Node world is reversed in this library (no 'method' and 'methodSync' naming). Asynchronous methods are those with 'Async' suffix, all methods without 'Async' in the name are synchronous. Reason behind this is that it gives very nice look to blocking API, and promise based non-blocking code is verbose anyway, so one more word is not much of a difference.

Thanks to that the API is also coherent...

// If method has no 'Async' suffix it gives you answer right away.
var data = jetpack.read('file.txt');
console.log(data);

// Want to make that call asnychronous? Just add the word "Async" 
// and it will give you promise instead of ready value.
jetpack.readAsync('file.txt')
.then(function (data) {
    console.log(data);
});

Every jetpack instance has its internal CWD

You can create many jetpack objects with different internal working directories (which are independent of process.cwd()) and work on directories in a little more object-oriented manner.

var src = jetpack.cwd('path/to/source');
var dest = jetpack.cwd('path/to/destination');
src.copy('foo.txt', dest.path('bar.txt'));

JSON is a first class citizen

You can write JavaScript object directly to disk and it will be transformed to JSON automatically.

var obj = { greet: "Hello World!" };
jetpack.write('file.json', obj);

Then you can get your object back just by telling read method that it's a JSON.

var obj = jetpack.read('file.json', 'json');

Throws errors at you as the last resort

Everyone who did something with files for sure seen "ENOENT, no such file or directory" error. Jetpack tries to recover from that error if possible.

1. For wrte/creation operations, if any of parent directories doesn't exist jetpack will just create them as well.
2. For read/inspect operations, if file or directory doesn't exist null is returned instead of throwing.

This is just a powerful API

All methods play nicely with each other. Here are few examples what it can give you.
Note: All examples are synchronous. Unfortunately asynchronous versions of them will be uglier :)

Files creation in declarative style

// To create structure...
// (CWD path)
// |- greets
//    |- greet.txt
//    |- greet.json
// |- greets-i18n
//    |- polish.txt

jetpack
.dir('greets')
    .file('greet.txt', { content: 'Hello World!' })
    .file('greet.json', { content: { greet: 'Hello World!' } })
    .cwd('..')
.dir('greets-i18n')
    .file('polish.txt', { content: 'Cześć!' });

Delete all tmp files inside directory tree

jetpack.find('my-dir', {
    matching: '*.tmp'
})
.forEach(jetpack.remove);

Check if two files have the same content

var file1 = jetpack.inspect('file1', { checksum: 'md5' });
var file2 = jetpack.inspect('file2', { checksum: 'md5' });
var areTheSame = (file1.md5 === file2.md5);

Great for build scripts

var src = jetpack.cwd('path/to/source');
var dest = jetpack.dir('path/to/destination', { empty: true });

src.copy('.', dest.path(), {
    matching: ['./vendor/**', '*.html', '*.png', '*.jpg']
});

var config = src.read('config.json', 'json');
config.env = 'production';
dest.write('config.json', config);

API Docs

API methods have blocking and non-blocking equivalents:

// Synchronous call
var data = jetpack.read('file.txt');
console.log(data);

// Asynchronous call
jetpack.readAsync('file.txt')
.then(function (data) {
    console.log(data);
});

Methods:

• append
• copy
• createReadStream
• createWriteStream
• cwd
• dir
• exists
• file
• find
• inspect
• inspectTree
• list
• move
• path
• read
• remove
• rename
• write

append(path, data, [options])

asynchronous: appendAsync(path, data, [options])

Appends given data to the end of file. If file (or any parent directory) doesn't exist, creates it (or them).

parameters:
path the path to file.
data data to append (could be String or Buffer).
options (optional) Object with possible fields:

• mode if the file doesn't exist yet, will be created with given mode. Value could be number (eg. 0700) or string (eg. '700').

returns:
Nothing.

copy(from, to, [options])

asynchronous: copyAsync(from, to, [options])

Copies given file or directory (with everything inside).

parameters:
from path to location you want to copy.
to path to destination location, where the copy should be placed.
options (optional) additional options for customization. Is an Object with possible fields:

• overwrite (default: false) Whether to overwrite destination path if it exists. For directories, source directory is merged with destination directory, so files in destination which are not present in the source, will remain intact.
• matching if defined will actually copy only items matching any of specified glob patterns and omit everything else (see examples below).

returns:
Nothing.

examples:

// Copies a file (and replaces it if one already exists in "somewhere" direcotry)
jetpack.copy('file.txt', 'somwhere/file.txt', { overwrite: true });

// Copies only .md files from my-dir to somewhere/my-dir
jetpack.copy('my-dir', 'somewhere/my-dir', { matching: '*.md' });

// When glob pattern starts with './' it means it is anchored to specified 
// directory to copy. Here will be copied only .jpg files from my-dir/images 
// and .md files from my-dir/articles
jetpack.copy('my_dir', 'somewhere/my_dir', { 
    matching: ['./images/**/*.jpg', './articles/**/*.md' ]
});

createReadStream(path, [options])

Just an alias to vanilla fs.createReadStream.

createWriteStream(path, [options])

Just an alias to vanilla fs.createWriteStream.

cwd([path...])

Returns Current Working Directory (CWD) for this instance of jetpack, or creates new jetpack object with given path as its internal CWD.
Note: fs-jetpack never changes value of process.cwd(), the CWD we are talking about here is internal value inside every jetpack instance.

parameters:
path... (optional) path (or many path parts) to become new CWD. Could be absolute, or relative. If relative path given new CWD will be resolved basing on current CWD of this jetpack instance.

returns:
If path not specified, returns CWD path of this jetpack object. For main instance of fs-jetpack it is always process.cwd().
If path specified, returns new jetpack object (totally the same thing as main jetpack). The new object resolves paths according to its internal CWD, not the global one (process.cwd()).

examples:

// Let's assume that process.cwd() outputs...
console.log(process.cwd()); // '/one/two/three'
// jetpack.cwd() will always return the same value as process.cwd()
console.log(jetpack.cwd()); // '/one/two/three'

// Now let's create new CWD context...
var jetParent = jetpack.cwd('..');
console.log(jetParent.cwd()); // '/one/two'
// ...and use this new context.
jetParent.dir('four'); // we just created directory '/one/two/four'

// One CWD context can be used to create next CWD context.
var jetParentParent = jetParent.cwd('..');
console.log(jetParentParent.cwd()); // '/one'

// When many parameters specified they are treated as parts of path to resolve
var sillyCwd = jetpack.cwd('a', 'b', 'c');
console.log(sillyCwd.cwd()); // '/one/two/three/a/b/c'

dir(path, [criteria])

asynchronous: dirAsync(path, [criteria])

Ensures that directory on given path exists and meets given criteria. If any criterium is not met it will be after this call.

parameters:
path path to directory to examine.
criteria (optional) criteria to be met by the directory. Is an Object with possible fields:

• empty (default: false) whether directory should be empty (no other files or directories inside). If set to true and directory contains any files or subdirectories all of them will be deleted.
• mode ensures directory has specified mode. If not set and directory already exists, current mode will be preserved. Value could be number (eg. 0700) or string (eg. '700').

returns:
New CWD context with directory specified in path as CWD.

examples:

// Creates directory if doesn't exist
jetpack.dir('new-dir');

// Makes sure directory mode is 0700 and that it's empty
jetpack.dir('empty-dir', { empty: true, mode: '700' });

// Because dir returns new CWD context pointing to just
// created directory you can create dir chains.
jetpack
.dir('main-dir') // creates 'main-dir'
.dir('sub-dir'); // creates 'main-dir/sub-dir'

exists(path)

asynchronous: existsAsync(path)

Checks whether something exists on given path. This method returns values more specyfic than true/false to protect from errors like "I was expecting directory, but it was a file".

returns:

• false if path doesn't exist.
• "dir" if path is a directory.
• "file" if path is a file.
• "other" if none of the above.

file(path, [criteria])

asynchronous: fileAsync(path, [criteria])

Ensures that file exists and meets given criteria. If any criterium is not met it will be after this call.

parameters:
path path to file to examine.
criteria (optional) criteria to be met by the file. Is an Object with possible fields:

• content sets file content. Could be String, Buffer, Object or Array. If Object or Array given to this parameter data will be written as JSON.
• jsonIndent (defaults to 2) if writing JSON data this tells how many spaces should one indentation have.
• mode ensures file has specified mode. If not set and file already exists, current mode will be preserved. Value could be number (eg. 0700) or string (eg. '700').

returns:
Jetpack object you called this method on (self).

examples:

// Creates file if doesn't exist
jetpack.file('something.txt');

// Creates file with mode '777' and content 'Hello World!'
jetpack.file('hello.txt', { mode: '777', content: 'Hello World!' });

find(path, searchOptions, [returnAs])

asynchronous: findAsync(path, searchOptions, [returnAs])

Finds in directory specified by path all files fulfilling searchOptions.

parameters:
path path to start search in (all subdirectories will be searched).
searchOptions is an Object with possible fields:

• matching glob patterns of files you would like to find. returnAs (optional) how the results should be returned. Could be one of:
• 'absolutePath' (default) returns array of absolute paths.
• 'relativePath' returns array of relative paths. The paths are relative to path you started search in.
• 'inspect' returns array of objects like you called inspect on every of those files.

returns:
Array of found files.

examples:

// Finds all files or directories which has 2015 in the name
jetpack.find('my-work', { matching: '*2015*' });

// Finds all jpg and png files and gives you back the list of inspect objects
// (like you called jetpack.inspect on every of those paths)
jetpack.find('my-work', { matching: ['*.jpg', '*.png'] }, 'inspect');

inspect(path, [options])

asynchronous: inspectAsync(path, [options])

Inspects given path (replacement for fs.stat). Returned object by default contains only very basic, not platform-dependent properties (so you have something e.g. your unit tests can rely on), you can enable more properties through options object.

parameters:
path path to inspect.
options (optional). Possible values:

• checksum if specified will return checksum of inspected file. Possible values are strings 'md5', 'sha1' or 'sha256'. If given path is directory this field is ignored.
• mode (default false) if set to true will add file mode (unix file permissions) value.
• times (default false) if set to true will add atime, mtime and ctime fields (here called accessTime, modifyTime and changeTime).
• absolutePath (dafault false) if set to true will add absolute path to this resource.

returns: null if given path doens't exist.
Otherwise Object of structure:

{
    name: "my_dir",
    type: "file", // possible values: "file", "dir"
    size: 123, // size in bytes, this is returned only for files
    // if checksum option was specified:
    md5: '900150983cd24fb0d6963f7d28e17f72',
    // if mode option was set to true:
    mode: 33204,
    // if times option was set to true:
    accessTime: [object Date],
    modifyTime: [object Date],
    changeTime: [object Date]
}

inspectTree(path, [options])

asynchronous: inspectTreeAsync(path, [options])

Calls inspect recursively on given path so it creates tree of all directories and sub-directories inside it.

parameters:
path the path to inspect.
options (optional). Possible values:

• checksum if specified will also calculate checksum of every item in the tree. Possible values are strings 'md5', 'sha1' or 'sha256'. Checksums for directories are calculated as checksum of all children' checksums plus their filenames (see example below).
• relativePath if set to true every tree node will have relative path anchored to root inspected folder.

returns:
null if given path doesn't exist. Otherwise tree of inspect objects like:

{
    name: 'my_dir',
    type: 'dir',
    size: 123, // this is combined size of all items in this directory
    relativePath: '.',
    md5: '11c68d9ad988ff4d98768193ab66a646',
    // checksum of this directory was calculated as:
    // md5(child[0].name + child[0].md5 + child[1].name + child[1].md5)
    children: [
        {
            name: 'empty',
            type: 'dir',
            size: 0, // the directory is empty
            relativePath: './dir',
            md5: null, // can't calculate checksum of empty directory
            children: []
        },{
            name: 'file.txt',
            type: 'file',
            size: 123,
            relativePath: './file.txt',
            md5: '900150983cd24fb0d6963f7d28e17f72'
        }
    ]
}

list(path, [useInspect])

asynchronous: listAsync(path, [useInspect])

Lists the contents of directory.

parameters:
path path to directory you would like to list.
useInspect (optional) the type of data this call should return. Possible values:

• false (default) returns just a list of filenames (the same as fs.readdir)
• true performs inspect on every item in directory, and returns array of those objects
• object if object has been passed to this parameter, it is treated as options parameter for inspect method, and will alter returned inspect objects

returns:
Array of strings or objects depending on call properies. Or null if given path doesn't exist.

move(from, to)

asynchronous: moveAsync(from, to)

Moves given path to new location.

parameters:
from path to directory or file you want to move.
to path where the thing should be moved.

returns:
Nothing.

path(parts...)

Returns path resolved to internal CWD of this jetpack object.

parameters:
parts strings to join and resolve as path (as many as you like).

returns:
Resolved path as string.

examples:

jetpack.cwd(); // if it returns '/one/two'
jetpack.path(); // this will return the same '/one/two'
jetpack.path('three'); // this will return '/one/two/three'
jetpack.path('..', 'four'); // this will return '/one/four'

read(path, [returnAs])

asynchronous: readAsync(path, [returnAs])

Reads content of file. If file on given path doesn't exist returns null instead of throwing error.

parameters:
path path to file.
returnAs (optional) how the content of file should be returned. Is a string with possible values:

• 'utf8' (default) content will be returned as UTF-8 String.
• 'buf' content will be returned as Buffer.
• 'json' content will be returned as parsed JSON object.
• 'jsonWithDates' content will be returned as parsed JSON object, and date strings in ISO format will be automatically turned into Date objects.

returns:
File content in specified format, or null if file doesn't exist.

remove(path)

asynchronous: removeAsync(path)

Deletes given path, no matter what it is (file or directory). If path already doesn't exist ends without throwing, so you can use it as 'ensure path doesn't exist'.

parameters:
path path to file or directory you want to remove.

returns:
Nothing.

examples:

// Deletes file
jetpack.remove('my_work/notes.txt');

// Deletes directory "important_stuff" and everything inside
jetpack.remove('my_work/important_stuff');

rename(path, newName)

asynchronous: renameAsync(path, newName)

Renames given file or directory.

parameters:
path path to thing you want to change name.
newName new name for this thing (not full path, just a name).

returns:
Nothing.

write(path, data, [options])

asynchronous: writeAsync(path, data, [options])

Writes data to file.

parameters:
path path to file.
content data to be written. This could be String, Buffer, Object or Array (if last two used, the data will be outputed into file as JSON).
options (optional) Object with possible fields:

• atomic (default false) if set to true the file will be written using strategy which is much more resistant to data loss. The trick is very simple, read this to get the concept.
• jsonIndent (defaults to 2) if writing JSON data this tells how many spaces should one indentation have.

returns:
Nothing.