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 [email protected]. 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.

License

Batcher is released under the MIT license.