rollup-plugin-jscc

Conditional compilation and compile-time variable replacement for Rollup.

rollup-plugin-jscc is not a transpiler, it is a wrapper of jscc, a tiny and powerful, language agnostic file preprocessor that uses JavaScript to transform text based on expressions at compile time.

With jscc, you have:

• Conditional inclusion/exclusion of blocks, based on compile-time variables*
• Compile-time variables with all the power of JavaScript expressions
• Replacement of variables in the sources, by its value at compile-time
• Sourcemap support, useful for JavaScript sources.
• TypeScript v3 definitions

* This feature allows you the conditional declaration of ES6 imports (See the example).

Since jscc is a preprocessor, rollup-plugin-jscc is implemented as a file loader, so it runs before any transpiler and is invisible to them. This behavior allows you to use it in a wide range of file types but, if necessary, it can be used as a Rollup transformer instead of a loader.

NOTE

v1.0.0 is a complete rewrite and there some changes, please read the specs in jscc wiki.

Also, removal of non-jscc comments is not included, but you can use rollup-plugin-cleanup, which brings compaction and normalization of lines in addition to the conditional removal of JS comments.

Install

npm i rollup-plugin-jscc -D
# or
yarn add rollup-plugin-jscc -D

rollup-plugin-jscc requires node.js v6 or later.

Usage

rollup.config.js

import { rollup } from 'rollup';
import jscc from 'rollup-plugin-jscc';

export default {
  input: 'src/main.js',
  plugins: [
    jscc({
      values: { _APPNAME: 'My App', _DEBUG: 1 },
    }),
  ],
  //...
}

in your source:

/*#if _DEBUG
import mylib from 'mylib-debug';
//#else */
import mylib from 'mylib';
//#endif

mylib.log('Starting $_APPNAME v$_VERSION...');

output:

import mylib from 'mylib-debug';

mylib.log('Starting My App v1.0.0...');

That's it.

* jscc has two predefined memvars: _FILE and _VERSION, in addition to giving access to the environment variables through the nodejs proccess.env object.

Options

Plain JavaScript object, with all properties optional.

Name | Type | Description ------------ | --------------- | ----------- escapeQuotes | string | String with the type of quotes to escape in the output of strings: 'single', 'double' or 'both'.Default nothing. keepLines | boolean | Preserves the empty lines of directives and blocks that were removed.Use this option with sourceMap:false if you are interested only in keeping the line numbering.Default false mapHires | boolean | Make a hi-res source-map, if sourceMap:true (the default).Default true prefixes | string | RegExp |Array<string|RegExp> | The start of a directive. That is the characters before the '#', usually the start of comments.Default ['//', '/*', '<!--'] (with one optional space after them). sourcemap | boolean | Must include a sourcemap?Should be the same value as the property sourcemap of the Rollup output.Default true mapContent | boolean | Include the original source in the sourcemap, if sourceMap:true (the default).Default true values | object | Plain object defining the variables used by jscc during the preprocessing.Default {} extensions | string | Array<string> | Array of strings that specifies the file extensions to process.Default ['js', 'jsx', 'ts', 'tsx', 'tag'] include | string | Array<string> | minimatch or array of minimatch patterns for paths that must be included in the processing. exclude | string | Array<string> | minimatch or array of minimatch patterns for paths that should be ignored.

Directives

Please see the jscc wiki to know about directives used by jscc.

What's New

• Only CommonJS version with dependency on jscc v1.1.0
• The minimum supported version of node.js is 6
• The predefined extensions were extended to include those of React and TypeScript.
• RegEx and Date values now outputs its literal content in replacements.
• Objects containing NaN now outputs NaN in replacements.
• Infinite and -Infinity in JSON objects are replaced with Number.MAX_VALUE and Number.MIN_VALUE, respectively.
• Added TypeScript v3 definitions.

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