webpack-remove-code-blocks

Webpack Remove Code Blocks

The webpack-remove-code-blocks removes blocks of code marked with special labels.

The loader can be incorporated into the build process to remove the code that you don't want to see in production. It supports the usage of multiple blocks. The loader was originated from Webpack Remove Block.

Install

# NPM
npm install --save-dev webpack-remove-code-blocks
# Yarn
yarn add --dev webpack-remove-code-blocks

Usage example

Let's start with a simple usage example. For example, we want to remove some code from a bundle while we build a project. To do that, we need to take a few simple steps.

Firstly, we need to add the loader and some additional settings to our webpack configuration:

module.exports = {
    module: {
        rules: [
            {
                test: /\.js$/,                                              // files we want to procces
                exclude: /(node_modules|bower_components|\.spec\.js)/,      // files we want to exclude
                use: [
                    {
                        loader: 'webpack-remove-code-blocks',               // use the loader
                    },
                ],
            },
        ],
    },
};

Then, we can mark unwanted blocks of code in our .js files using comments with the special syntax devblock:start and devblock:end:

/* devblock:start */
console.log('something not for production');
/* devblock:end */

After the bundling process, the marked blocks will be removed (the comments will be removed too).

Advanced usage example

Let's suppose, that we have a more sophisticated task. We want to use different labels (we might want to keep some code in staging, but not in the production environment) and process different file extensions. That's not a problem.

The only thing we need to do is to provide some additional settings to our webpack configuration:

module.exports = {
    module: {
        rules: [
            {
                test: /\.js|\.ts|\.tsx$/,                                   // files we want to procces
                exclude: /(node_modules|bower_components|\.spec\.js)/,      // files we want to exclude
                use: [
                    {
                        loader: 'webpack-remove-code-blocks',               // use the loader
                        options: {
                            blocks: [                                       // define three different blocks
                                'debug',
                                'devblock',
                                {
                                    start: 'devblock_start',
                                    end: 'devblock_end',
                                    prefix: '/*',
                                    suffix: '*/',
                                },
                            ],
                        },
                    },
                ],
            },
        ],
    },
};

Let's now build our project with this code inside:

/* debug:start */
console.log('debug');
/* debug:end */
var makeFoo = function(bar, baz) {
    // The following code will be removed with the loader
    /* devblock:start */
    if (bar instanceof Bar !== true) {
        throw new Error('makeFoo: bar param is required and must be instance of Bar');
    }
    /* devblock:end */
    /* devblock_start */
    if (baz instanceof Baz !== true) {
        throw new Error('makeFoo: baz param is required and must be instance of Baz');
    }
    /* devblock_end */

    // This code will remain
    return new Foo(bar, baz);
}

After the bundling process, the result will be as follows:

var makeFoo = function(bar, baz) {
    // The following code will be removed with the loader

    // This code will remain
    return new Foo(bar, baz);
}

Options

If you want to define different comment blocks, use the options.blocks array. Each element of the array describes a unique block of comments to be removed. The block can be described by an object with the following properties:

start: 'dev_start',             # a string value that defines the beginning of a block to remove
end: 'dev_end',                 # a string value that defines the end of a block to remove
prefix: '/*',                   # a string value that defines the beginning of a comment
suffix: '*/',                   # a string value that defines the end of a comment

Or, if you don't want to clutter your configuration, a block can be described by just a simple string. The string debug will represent a block of comments with the following properties:

start: 'debug:start',
end: 'debug:end',
prefix: '/*',
suffix: '*/',

License

The MIT License (MIT). Please see License File for more information.