Batcher NPM | npm.io

batcher

Batch processor of shell commands and javascript functions over shared state object. Async, sequential, parallel.

Notice of change of ownership: Starting version 1.0.0 this package has changed it's owner and goals. Old version (0.0.2) is still available on npm via npm install batcher@0.0.2. Thank you.

Why

Some tasks (e.g. deploy scripts) better implemented using shell commands, some tasks require nodejs power, this module allows to bring them together in a simple, yet powerful "batch" script and combine via shared state object.

Features

Executes provided shell commands asynchronously and sequentially.
Shares state object among all specified tasks.
Allows to update state with output from shell commands.
Allows for parallel execution of the commands.
Accepts custom (sync and async) functions as tasks.
Provides markdown-compatible default reporter.
Natively supports custom reporters.

Install

npm install --save batcher

Examples

Following setup:

var batcher = require('batcher');

batcher({
  word: 'ABC'
},
[
  // simple shell command
  'echo A',

  // using state variable
  'echo word is ${word}',

  // updating state
  {twoWords: 'echo ${word} + ${word}'},

  // reusing updated state
  'echo two words are ${twoWords}',

  // parallel execution
  ['echo Marco', 'echo Polo'],

  // custom sync function as a task
  function()
  {
    return this.twoWords.substr(0, 5);
  },

  // custom async function as a task
  function(cb)
  {
    cb(null, this.twoWords.substr(0, 8));
  },

  // for arrow functions it passes context as first argument
  { newWord: context => `${context.word}/${context.word}` },

  // same goes for asynchronous arrow functions
  (context, cb) => {
    cb(null, context.newWord.split('/'))
  }
]);

Outputs (with default reporter):

# Started batch process

## Initial State:

```
{
  "word": "ABC"
}
```

## Execution


### Executing `` echo A ``...

> Finished execution of `` echo A ``:
```
A
```

### Executing `` echo word is ${word} ``...

> Finished execution of `` echo word is ${word} ``:
```
word is ABC
```

### Executing `` echo ${word} + ${word} ``...

> Storing output into `` twoWords ``

> Finished execution of `` echo ${word} + ${word} ``:
```
ABC + ABC
```

### Executing `` echo two words are ${twoWords} ``...

> Finished execution of `` echo two words are ${twoWords} ``:
```
two words are ABC + ABC
```

### Executing `` echo Marco ``...


### Executing `` echo Polo ``...

> Finished execution of `` echo Marco ``:
```
Marco
```
> Finished execution of `` echo Polo ``:
```
Polo
```

### Executing `` function () { return this.twoWords.substr(0, 5); } ``...

> Finished execution of `` function () { return this.twoWords.substr(0, 5); } ``:
```
ABC +
```

### Executing `` function (cb) { cb(null, this.twoWords.substr(0, 8)); } ``...

> Finished execution of `` function (cb) { cb(null, this.twoWords.substr(0, 8)); } ``:
```
ABC + AB
```

### Executing `` context => `${context.word}/${context.word}` ``...

> Storing output into `` newWord ``

> Finished execution of `` context => `${context.word}/${context.word}` ``:
```
ABC/ABC
```

### Executing `` (context, cb) => { cb(null, context.newWord.split('/')) } ``...

> Finished execution of `` (context, cb) => { cb(null, context.newWord.split('/')) } ``:
```
ABC
ABC
```

## Final State:

```
{
  "newWord": "ABC/ABC",
  "twoWords": "ABC + ABC",
  "word": "ABC"
}
```

For more examples check out example.js and example.md for default output, and tests folder for advanced usage examples.