Refactor. Update dependencies. Update tests. Make img plugin async.

lib/css-url.js

@@ -0,0 +1,133 @@
+const datauri = require('datauri');
+const isLocalPath = require('is-local-path');
+const isTemplateExpression = require('./is-template-expression');
+const path = require('path');
+const postcss = require('postcss');
+const postcssUrl = require('postcss-url');
+const R = require('ramda');
+const string = require('string');
+const url = require('url');
+
+const collapseWhitespace = str => string(str).collapseWhitespace().toString();
+const forEachIndexed = R.addIndex(R.forEach);
+const format = (path) => url.format(path);
+const parse = (path) => url.parse(path);
+const resolve = path.resolve;
+
+const augmentError = (error, filename, files) => {
+	if (!error.filename) error.filename = filename;
+	error.files = R.uniq(R.concat(files, error.files || []));
+	return error;
+};
+
+/**
+ * Returns url path without query string and hash if present.
+ *
+ * @param path
+ *
+ * @returns path
+ */
+const cleanUrl = R.pipe(
+	parse,
+	R.pick(['protocol', 'host', 'pathname']),
+	format,
+	decodeURI
+);
+/**
+ * Convert local url data type paths to datauris.
+ *
+ * @param css
+ * @param filename
+ * @returns {{css: (css|any), files: Array}}
+ */
+const inlineUrl = R.curry((filename, css) => {
+	const basePath = path.dirname(filename);
+	var files = [];
+	const inline = url => {
+		try {
+			if (isLocalPath(url) && !isTemplateExpression(url)) {
+				url = cleanUrl(url);
+				url = resolve(basePath, url);
+				files = R.append(url, files);
+				url = datauri(url);
+			}
+			return url;
+		}
+		catch (error) { throw augmentError(error, filename, files); }
+	};
+	css = postcss()
+		.use(postcssUrl({ url: inline }))
+		.process(css)
+		.css;
+	files = R.uniq(files);
+	return { css, files };
+});
+
+const inlineStyles = ($, filename) => {
+	var files = [];
+	try {
+		const styles = $('style')
+			.toArray();
+
+		const contents = R.map(style => {
+			const css = $(style).html();
+			const result = inlineUrl(filename, css);
+			files = R.concat(files, result.files);
+			return result.css;
+		}, styles);
+
+		forEachIndexed((style, index) => $(style).html(contents[index]), styles);
+
+		return { $, files };
+	}
+	catch (error) { throw augmentError(error, filename, files); }
+};
+
+const prefix = 'selector {';
+const suffix = '}';
+const matchStyle = new RegExp(`^${prefix}\\s*(.*)\\s*${suffix}$`);
+const wrap = style => `${prefix}${style}${suffix}`;
+const unwrap = rule => rule.replace(matchStyle, '$1');
+
+const inlineStyleAttributes = ($, filename) => {
+	var files = [];
+	try {
+		const elements = $('*')
+			.filter('[style]')
+			.toArray();
+
+		const styles = R.map(element => {
+			var style = $(element).attr('style');
+			const rule = wrap(style);
+			const result = inlineUrl(filename, rule);
+			files = R.concat(files, result.files);
+			style = R.pipe( collapseWhitespace, unwrap )(result.css);
+			return style;
+		}, elements);
+
+		forEachIndexed((element, index) => $(element).attr('style', styles[index]), elements);
+
+		return { $, files };
+	}
+	catch (error) { throw augmentError(error, filename, files); }
+};
+
+const inlineCssUrl = function ($, filename) {
+	var files = [];
+	try {
+		var result;
+		result = inlineStyles($, filename);
+		$ = result.$;
+		files = R.concat(files, result.files);
+
+		result = inlineStyleAttributes($, filename);
+		$ = result.$;
+		files = R.concat(files, result.files);
+
+		files = R.uniq(files);
+		return { $, files };
+	}
+	catch (error) { throw augmentError(error, filename, files); }
+};
+
+module.exports = inlineCssUrl;