Package Exports
- rollup-plugin-jscc
This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (rollup-plugin-jscc) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.
Readme
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
The 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.
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Install
npm i rollup-plugin-jscc -D
# or
yarn add rollup-plugin-jscc -D
rollup-plugin-jscc requires rollup v2.0 and node.js v10.12 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 },
}),
],
//...other options
}
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 |
---|---|---|
asloader | boolean | If false , run the plugin as a transformer , otherwise run as loader (the default). |
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', 'mjs', '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
Please see the CHANGELOG.
License
The MIT License