@cuties/cutie

    1.7.6 • Public • Published

    NPM Version Build Status codecov

    Cutie is a lightweight library that implements Async Tree Pattern.

    Motivation

    Let's say we want to read content from a file and write it to another one. And all these operations are asynchronous, of course. So, instead of writing something like this:

    fs.readFile('./../file1.txt', 'utf8', (err, result) => {
      if (err != null) {
        throw err
      }
     
      fs.writeFile('./../file2.txt', result, (err) => {
        if (err != null) {
          throw err
        }
      })
    })

    we can design our code in the following style:

    new WrittenFile(
      './../file2.txt',
      new ReadDataByPath('./../file1.txt', 'utf8')
    ).call()

    How to use

    You can use Cutie as a dependency via npm: npm install @cuties/cutie

    const AsyncObject = require('@cuties/cutie').AsyncObject
    const fs = require('fs')
     
    // Represents file as path
    class WrittenFile extends AsyncObject {
      constructor (path, content) {
        super(path, content)
      }
      
      asyncCall () {
        return (path, content, callback) => {
          this.path = path
          fs.writeFile(path, content, callback)
        }
      }
     
      onResult() {
        return this.path
      }
    }
    const AsyncObject = require('@cuties/cutie').AsyncObject
    const fs = require('fs')
     
    // Represents buffer or string
    class ReadDataByPath extends AsyncObject {
      constructor (path, encoding) {
        super(path, encoding);
      }
      
      asyncCall () {
        return fs.readFile
      }
    }

    AsyncObject also provides methods OnResult and OnError, so that you can process the result (it's provided by callback by default) from async call and handle an error in the specific way (error is being thrown by default).

    Let's say we want to read a json file and parse all information from there. Cutie provides two ways. First of them is just to create ParsedJSON async object like this:

    const AsyncObject = require('@cuties/cutie').AsyncObject;
    const fs = require('fs');
     
    class ParsedJSON extends AsyncObject {
      constructor (path, encoding) {
        super(path, encoding)
      }
      
      asyncCall () {
        return fs.readFile
      }
      
      onResult (result) {
        return JSON.parse(result)
      }
    }
     
    // usage
    new ParsedJSON('./../file.txt', 'utf8').call()

    ParsedJSON also could be designed like this:

    const fs = require('fs')
    const ReadDataByPath = require('./ReadDataByPath')
     
    class ParsedJSON extends ReadDataByPath {
      constructor (path, encoding) {
        super(path, encoding)
      }
      
      onResult (result) {
        return JSON.parse(result)
      }
    }
     
    // usage
    new ParsedJSON('./../file.txt', 'utf8').call();

    Or you can use ReadDataByPath with ParsedJSON that looks like this:

    const AsyncObject = require('@cuties/cutie').AsyncObject
    const fs = require('fs')
    const ReadDataByPath = require('./ReadDataByPath')
     
    class ParsedJSON extends AsyncObject {
      constructor (text) {
        super(text)
      }
      
      /*
        you can't call here async operations with I/O
      */
      syncCall () {
        return JSON.parse
      }
    }
     
    // usage
    new ParsedJSON(
      new ReadDataByPath('./../file.txt', 'utf8')
    ).call()

    Read more

    1. Async Tree Pattern
    2. Async Objects instead of Async Calls

    Run test

    npm test

    Run build

    npm run build

    Libraries that use cutie

    node-test-executor, cutie-is, cutie-assert, cutie-fs, cutie-http, cutie-https, cutie-rest, cutie-buffer, cutie-error, cutie-date, cutie-json, cutie-event, cutie-stream, cutie-object, cutie-process, cutie-iterator, cutie-path, cutie-if-else, cutie-cluster, page-static-generator and many others.

    Install

    npm i @cuties/cutie

    DownloadsWeekly Downloads

    4

    Version

    1.7.6

    License

    MIT

    Unpacked Size

    38.3 kB

    Total Files

    46

    Last publish

    Collaborators

    • guseyn