Diverge

Dead simple conditional build tool.

• Installation
• Usage
  • Directives
  • Comparison
  • Instrumenting
  • Compiling
• API

Installation

npm install diverge

Usage

  Usage: diverge <input> <output>
 
  Options:
 
    -h, --help     output usage information
    -V, --version  output the version number
    -f, --force    forces overwrite of output file
 
  Examples:
 
    $     env=cjs diverge common.js cjs.js
    $  env=meteor diverge common.js meteor.js
    $ env=globals diverge common.js globals.js

Directives

There's 4 conditional directives available:

• diverge:if
• diverge:elif
• diverge:else
• diverge:fi

Comparison

You can use both equality and inequality operators:

// diverge:if env=browser
var equality = 'is browser';
// diverge:elif env!=browser
var inequality = 'is not browser';
// diverge:fi

Instrumenting

In this example, we have a javascript file which we want to use in:

• commonjs
• globals
• meteor

So, first we need to instrument it:

sample.js

// diverge:if env=cjs
module.exports
// diverge:elif env=meteor
MyModule
// diverge:else
window.MyModule;
// diverge:fi
 
= function(){
  console.log('Hello World');
}

Note that comments are used so the original functionality doesn't get modified whatsoever. You can do the same for the text file you're dealing with.

In the next step we'll see how we send the env value so our conditionals can work properly.

Compiling

In order to compile we need to set our variables accordingly, as we expect them. In this example, we're checking conditions against the env variable. So we set it right before the diverge call.

Lets see three examples and their corresponding outputs:

// $ env=cjs diverge sample.js cjs.js
module.exports
= function(){
  console.log('Hello World');
}

// $ env=meteor diverge sample.js meteor.js
MyModule
= function(){
  console.log('Hello World');
}

// $ env=globals diverge sample.js globals.js
window.MyModule
= function(){
  console.log('Hello World');
}

Programatic API

Signature is such as follows:

diverge(<input>, <output>, {locals}, {options});
 
/*
    input - input file path
   output - output file path
   locals - variables accessible to instrumented code
  options - same as CLI options
 */

Practical example:

var diverge = require('diverge');
 
diverge('source.js', 'cjs.js', {env: 'cjs'}, {force: true});

1. Note that in the CLI mode our variables (locals) gets read from process.env but in the Javascript mode, we need to explicitly set them.

2. The options are the same of the CLI, but informed without aliases / dashes.

License

The MIT License (MIT)

Copyright (c) 2015 Anderson Arboleya

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.