un-css
Version:
Remove unused CSS styles
231 lines (210 loc) • 7.54 kB
JavaScript
;
var promise = require('bluebird'),
css = require('css'),
fs = require('fs'),
glob = require('glob'),
isHTML = require('is-html'),
isURL = require('is-absolute-url'),
phantom = require('./phantom.js'),
uncss = require('./lib.js'),
utility = require('./utility.js'),
_ = require('lodash');
/**
* Get the contents of HTML pages through PhantomJS.
* @param {Array} files List of HTML files
* @param {Object} options UnCSS options
* @return {promise}
*/
function getHTML(files, options) {
if (_.isString(files)) {
return phantom.fromRaw(files, options.timeout).then(function (pages) {
return [files, options, [pages]];
});
}
files = _.flatten(files.map(function (file) {
if (!isURL(file) && !isHTML(file)) {
return glob.sync(file);
}
return file;
}));
if (!files.length) {
throw new Error('UnCSS: no HTML files found');
}
return promise.map(files, function (filename) {
if (isURL(filename)) {
return phantom.fromRemote(filename, options);
}
if (fs.existsSync(filename)) {
return phantom.fromLocal(filename, options);
}
// raw html
return phantom.fromRaw(filename, options);
}).then(function (pages) {
return [files, options, pages];
});
}
/**
* Get the contents of CSS files.
* @param {Array} files List of HTML files
* @param {Object} options UnCSS options
* @param {Array} pages Pages opened by phridge
* @return {promise}
*/
function getStylesheets(files, options, pages) {
if (options.stylesheets && options.stylesheets.length) {
/* Simulate the behavior below */
return [files, options, pages, [options.stylesheets]];
}
/* Extract the stylesheets from the HTML */
return promise.map(pages, function (page) {
return phantom.getStylesheets(page, options);
}).then(function (stylesheets) {
return [files, options, pages, stylesheets];
});
}
/**
* Get the contents of CSS files.
* @param {Array} files List of HTML files
* @param {Object} options UnCSS options
* @param {Array} pages Pages opened by phridge
* @param {Array} stylesheets List of CSS files
* @return {promise}
*/
function getCSS(files, options, pages, stylesheets) {
/* Ignore specified stylesheets */
if (options.ignoreSheets.length) {
stylesheets = stylesheets.map(function (arr) {
return arr.filter(function (sheet) {
return _.every(options.ignoreSheets, function (ignore) {
if (_.isRegExp(ignore)) {
return !ignore.test(sheet);
}
return sheet !== ignore;
});
});
});
}
if (_.flatten(stylesheets).length) {
/* Only run this if we found links to stylesheets (there may be none...)
* files = ['some_file.html', 'some_other_file.html']
* stylesheets = [['relative_css_path.css', ...],
* ['maybe_a_duplicate.css', ...]]
* We need to - make the stylesheets' paths relative to the HTML files,
* - flatten the array,
* - remove duplicates
*/
stylesheets =
_.chain(stylesheets)
.map(function (sheets, i) {
return utility.parsePaths(files[i], sheets, options);
})
.flatten()
.uniq()
.value();
} else {
/* Reset the array if we didn't find any link tags */
stylesheets = [];
}
return [files, options, pages, utility.readStylesheets(stylesheets)];
}
/**
* Do the actual work
* @param {Array} files List of HTML files
* @param {Object} options UnCSS options
* @param {Array} pages Pages opened by phridge
* @param {Array} stylesheets List of CSS files
* @return {promise}
*/
function process(files, options, pages, stylesheets) {
/* If we specified a raw string of CSS, add it to the stylesheets array */
if (options.raw) {
if (_.isString(options.raw)) {
stylesheets.push(options.raw);
} else {
throw new Error('UnCSS: options.raw - expected a string');
}
}
/* At this point, there isn't any point in running the rest of the task if:
* - We didn't specify any stylesheet links in the options object
* - We couldn't find any stylesheet links in the HTML itself
* - We weren't passed a string of raw CSS in addition to, or to replace
* either of the above
*/
if (!_.flatten(stylesheets).length) {
throw new Error('UnCSS: no stylesheets found');
}
/* OK, so we have some CSS to work with!
* Three steps:
* - Parse the CSS
* - Remove the unused rules
* - Return the optimized CSS as a string
*/
var cssStr = stylesheets.join(' \n'),
parsed, report;
try {
parsed = css.parse(cssStr);
} catch (err) {
/* Try and construct a helpful error message */
throw utility.parseErrorMessage(err, cssStr);
}
return uncss(pages, parsed.stylesheet, options.ignore).spread(function (used, rep) {
var usedCss = css.stringify(used);
if (options.report) {
report = {
original: cssStr,
selectors: rep
};
}
return new promise(function (resolve) {
resolve([usedCss + '\n', report]);
});
});
}
/**
* Main exposed function.
* Here we check the options and callback, then run the files through PhantomJS.
* @param {Array} files Array of filenames
* @param {Object} [options] options
* @param {Function} callback(Error, String, Object)
* @return {promise}
*/
function init(files, options, callback) {
if (_.isFunction(options)) {
/* There were no options, this argument is actually the callback */
callback = options;
options = {};
} else if (!_.isFunction(callback)) {
throw new TypeError('UnCSS: expected a callback');
}
/* Try and read options from the specified uncssrc file */
if (options.uncssrc) {
try {
/* Manually-specified options take precedence over uncssrc options */
options = _.merge(utility.parseUncssrc(options.uncssrc), options);
} catch (err) {
if (err instanceof SyntaxError) {
return callback(new SyntaxError('UnCSS: uncssrc file is invalid JSON.'));
}
return callback(err);
}
}
/* Assign default values to options, unless specified */
options = _.defaults(options, {
csspath: '',
ignore: [],
media: [],
timeout: 0,
report: false,
ignoreSheets: [],
httpSetting: {},
});
return promise
.using(phantom.init(options.phantom, options.httpSetting), function () {
return getHTML(files, options)
.spread(getStylesheets)
.spread(getCSS)
.spread(process);
})
.nodeify(callback, { spread: true });
}
module.exports = init;