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cost

A CLI tool for checking the size of files after minifying and gzipping them. MIME types are checked to determine whether to minify and/or gzip the file. To mimic the behavior of most web servers, only CSS and JS files are minified, and the compressible module is used to determine whether to gzip a file or not.

Installation

$ sudo npm install -g cost

Usage

Basic usage:

$ cost /path/to/file.jpg
>> 640 kB

Multiple files:

$ cost /path/to/file.js ../path/to/other/file.png
>> /path/to/file.js
>> 640 kB (minified, gzipped)
>> ../path/to/other/file.png
>> 2.3 MB

Remote files:

$ cost https://mydomain.com/myfile.txt
>> 21 kB (gzipped)

Standard input:

$ echo hello world | cost
>> 12 B

Options

--help, -?        Display help information
--bytes, -b       Always display size in bytes (not kB, MB, etc.)
--simple, -s      Hide details about whether files were gzipped or minified
--raw, -r         Don't minify or gzip any files

Forcefully cause gzip/minify:

$ cost :css:/path/to/file
>> xxx kB (minified)

$ cost :gzip:/path/to/file
>> xxx kB (gzipped)

$ cost :js,gzip:/path/to/file
>> xxx kB (minified, gzipped)

Forcefully skip gzipping/minification:

$ cost :max:/path/to/file.js
>> xxx kB (gzipped)

$ cost :unzip:/path/to/file.js
>> xxx kB (minified)

$ cost :max,unzip:/path/to/file.js
>> xxx kB

You can do this with stdin too:

$ echo hello world | cost :js:
>> ERROR: Unexpected token: name (world)

These per-file options supercede the standard options. For example, the following operation will do minification, but not gzipping:

$ cost --raw :js:/path/to/file

Useful Information

When used on a local file, the file extension is used to determine the MIME type, which is used to decide whether to minify and/or gzip the file. When used on a remote file, the Content-Type header is checked to determine the MIME type, and the URL's file extension is used as a fallback.

This logic can be overwritten manually (see Options).

uglify-js is used for JavaScript minifcation, and clean-css is used for CSS minification.

The CSS minifiction does NOT follow @import directives.

Programmatic Usage

The main module uses promises (A+).

var cost = require('cost');

cost('/path/to/file.js')
	.then(function (result) {
		console.log(result.value + ' bytes');
		// >> 62 bytes
		
		if (result.gzip) {
			console.log('file was gzipped')
		}
		
		if (result.minify) {
			console.log('file was %s minified', result.minify);
			// >> file was js minified
		}
	})
	.catch(function (err) {
		console.log(err.message);
	});
	
	
cost({
	path: '/path/to/file.js',
	minify: false, // could be 'js', 'css', or false
	gzip: true
}).then(handleResult).catch(handleErrors);


// You can pass a string instead of a path.
// But when you do, minification and gzipping will not happen unless
// specified by you, because automatic MIME type detection cannot occur.
cost({
	value: myCssString,
	minify: 'css',
	gzip: true
}).then(handleResult).catch(handleErrors);