wrote

wrote

Promise-based write and read operations for Node.js

ES5

The package uses some newer language features. For your convenience, it's been transpiled to be compatible with Node 4. You can use the following snippet.

const wrote = require('wrote/es5/src/')

wrote.createWritable(path=: string): Promise.<Writable>

Create an open Writable stream to the file.

const { Writable } = require('stream')
const path = require('path')
const HOME_DIR = require('os').homedir()
const { createWritable } = require('wrote')

const file = path.join(HOME_DIR, `wrote-${Math.floor(Math.random() * 1e5)}.data`);

(async () => {
    const ws = await createWritable(file)
    console.log(ws instanceof Writable) // true
    console.log(ws.path) // ~/wrote-35558.data
})()

If you don't have a file, a new one in the temp directory will be created for you.

(async () => {
    const ws = await createWritable()
    console.log(ws instanceof Writable) // true
    console.log(ws.path) // /var/folders/s0/1h2g/T/wrote-48315.data
})()

wrote.exists(path: string): Promise.<boolean>

Check if the path on the filesystem exists. Throws if path is not accessible due to permissions.

const { exists } = require('wrote');

(async () => {
    await exists('unknown-path') // false
    await exists(__filename) // true
    await exists(__dirname) // true
})()

wrote.assertExists(path: string): Promise

Check if the path on the filesystem exists, and throw if it does not, or cannot be accessed.

const { assertExists } = require('wrote');

(async () => {
    try {
        await assertExists('unknown-path')
    } catch (err) {
        console.log(err) // Path unknown-path does not exist.
    }
    await assertExists(__filename) // ok
})()

wrote.assertDoesNotExist(path: string): Promise

Check if the path on the filesystem does not exists, and throw if it does, or cannot be accessed.

const { assertDoesNotExist } = require('wrote');

(async () => {
    try {
        await assertDoesNotExist(__filename)
    } catch (err) {
        console.log(err) // Path /wrote/examples/assert-does-not-exist.js exists.
    }
    await assertDoesNotExist('unknown-file') // ok
})()

wrote.clone({ from: string, to: string, regexes: [] }): Promise

Clone a directory by copying contents of files and creating symlinks. Regular expressions can be used to transform data being copied.

const { clone } = require('wrote');

(async () => {
    const from = './directory'
    const to = './clone'

    await clone({
        from,
        to,
        regexes: [
            {
                re: /{{ name }}/g, // use /g flag for global replacements
                replacement: 'Garry',
            },
            {
                re: /{{ age }}/,
                replacement: '30',
            },
        ],
    })
    // or,
    // await clone({ to, from })
})()

wrote.erase(ws: Writable): Promise.<Writable>

Erase file and close stream.

const { createWritable, erase } = require('wrote')
const { Writable } = require('stream')
const path = require('path')
const HOME_DIR = require('os').homedir()

const file = path.join(HOME_DIR, `wrote-${Math.floor(Math.random() * 1e5)}.data`);

(async () => {
    const ws = await createWritable(file)
    console.log(ws instanceof Writable) // true
    console.log(ws.writable) // true
    console.log(ws.path) // ~/wrote-35558.data
    await erase(ws)
    console.log(ws.closed) // true
})()

wrote.write(ws: Writable, data?: string|Readable): Promise.<Writable>

Pipe a Readable to the Writable stream and wait until it is finished, or end Writable with given data (pass null to end stream without any more data).

const { write } = require('wrote')
const assert = require('assert')
const { Writable } = require('stream')

const testString = 'hello world'
const buffer = Buffer.from(testString)
const allRawData = []
const ws = new Writable({
    write(chunk, encoding, next) {
        allRawData.push(chunk)
        next()
    },
});

(async () => {
    await write(ws, buffer)
    console.log(allRawData.map(d => String(d))) // [ 'hello world' ]
    assert.deepEqual(allRawData, [
        buffer,
    ])
})()

wrote.ensurePath(filePath: string): Promise<string>

Create all required directories for the filepath to exist. If a directory on the way is non-executable, the Promise will be rejected. Resolves with the filepath.

const { ensurePath } = require('wrote')
const { resolve } = require('path');

(async () => {
    const path = 'path/to/temp/file.data'
    const res = await ensurePath(path)
    console.log(res) // path/to/temp/file.data, path/to/temp is created in your cwd

    const absolutePath = resolve(process.cwd(), 'path/to/temp/file.data')
    const res2 = await ensurePath(absolutePath)
    console.log(res2) // $(pwd)/path/to/temp/file.data
})()

wrote.read(path: string): Promise.<string>

Read a file fully. Returns a Promise resolved with the file contents, and rejects if path is not a string or file not found (ENOENT).

const { read } = require('wrote');

(async () => {
    const res = await read(__filename)
    console.log(res)
})()

examples/read.js: this program will print the contents of itself

wrote.readJSON(path: string): Promise.<object>

Read a json file and parse its contents.

const { readJSON } = require('wrote');

(async () => {
    const res = await read('path/to/file.json')
    console.log(res)
})()

wrote.writeJSON(path: string, object: object, { replacer?: function, space?: string|number }): Promise

Serialise an object with JSON.stringify and write it to a file. Pass space and replacer in the options object.

const { writeJSON } = require('wrote');

(async () => {
    const object = {
        test: 'data',
        date: new Date(),
    }
    await writeJSON('path/to/file.json', object, {
        space: 2,
        // replacer: () => {}
    })
})()

wrote.readDir(dirPath: string, recursive=: boolean): Promise<object>

Read a directory, and return contents of contained files.

For example, the following directory structure:

directory
 - subdirectory
    - subdirFileA.txt
    ` subdirFileB.txt
 - fileA.txt
 - fileB.txt
 ` fileC.txt

can be read either shallowly (by default):

const { readDir } = require('wrote')
const path = require('path')

const dirPath = path.join(__dirname, 'directory');

(async () => {
    const res = await readDir(dirPath)
    console.log(res)
    // { 'fileA.txt': 'fileA\n',
    //   'fileB.txt': 'fileB\n',
    //   'fileC.txt': 'fileC\n' }
})()

or recursively:

(async () => {
    const res = await readDir(dirPath, true)
    console.log(res)
    // { 'fileA.txt': 'fileA\n',
    //   'fileB.txt': 'fileB\n',
    //   'fileC.txt': 'fileC\n',
    //   subdirectory:
    //    { 'subdirFileA.txt': 'subdirFileA\n',
    //      'subdirFileB.txt': 'subdirFileB\n' } }
})()

wrote.readDirStructure(dirPath: string): Promise<DirectoryStructure>

Get the full structure of the directory recursively. An array of either file names as strings, or an object representing all directories of the current one, with keys being their names, and values being arrays similar to the root one.

const path = require('path')
const { readDirStructure } = require('..')

const DIR_PATH = path.join(__dirname, '../test/fixtures/directory');

/**
 * Read directory's structure.
 */

(async () => {
    const res = await readDirStructure(DIR_PATH)
    console.log(JSON.stringify(res, null, 2))
})()

{
  "type": "Directory",
  "content": {
    "subdirectory-ln": {
      "type": "SymbolicLink"
    },
    "test-ln.data": {
      "type": "SymbolicLink"
    },
    "test.data": {
      "type": "File"
    },
    "subdirectory": {
      "type": "Directory",
      "content": {
        "file.data": {
          "type": "File"
        },
        "file2.data": {
          "type": "File"
        }
      }
    },
    "subdirectory2": {
      "type": "Directory",
      "content": {
        "file3.data": {
          "type": "File"
        },
        "subsubdir": {
          "type": "Directory",
          "content": {
            "file4.py": {
              "type": "File"
            }
          }
        },
        "subsubdir2": {
          "type": "Directory",
          "content": {}
        }
      }
    }
  }
}

todo

• pass options to fs.createWriteStream in wrote.createWritable

---

Licence: MIT

(c) Sobesednik-Media 2017

Changelog

1.3.0

• [feature] writeJSON, readJSON

30 December 2017