141 lines
4.2 KiB
JavaScript
141 lines
4.2 KiB
JavaScript
'use strict';
|
|
|
|
/**
|
|
* @typedef {import('../lib/types').XastElement} XastElement
|
|
* @typedef {import('../lib/types').XastParent} XastParent
|
|
*/
|
|
|
|
const csso = require('csso');
|
|
const { detachNodeFromParent } = require('../lib/xast');
|
|
const { hasScripts } = require('../lib/svgo/tools');
|
|
|
|
exports.name = 'minifyStyles';
|
|
exports.description = 'minifies styles and removes unused styles';
|
|
|
|
/**
|
|
* Minifies styles (<style> element + style attribute) using CSSO.
|
|
*
|
|
* @author strarsis <strarsis@gmail.com>
|
|
* @type {import('./plugins-types').Plugin<'minifyStyles'>}
|
|
*/
|
|
exports.fn = (_root, { usage, ...params }) => {
|
|
/** @type {Map<XastElement, XastParent>} */
|
|
const styleElements = new Map();
|
|
|
|
/** @type {Array<XastElement>} */
|
|
const elementsWithStyleAttributes = [];
|
|
|
|
/** @type {Set<string>} */
|
|
const tagsUsage = new Set();
|
|
|
|
/** @type {Set<string>} */
|
|
const idsUsage = new Set();
|
|
|
|
/** @type {Set<string>} */
|
|
const classesUsage = new Set();
|
|
|
|
let enableTagsUsage = true;
|
|
let enableIdsUsage = true;
|
|
let enableClassesUsage = true;
|
|
|
|
/**
|
|
* Force to use usage data even if it unsafe. For example, the document
|
|
* contains scripts or in attributes..
|
|
*/
|
|
let forceUsageDeoptimized = false;
|
|
|
|
if (typeof usage === 'boolean') {
|
|
enableTagsUsage = usage;
|
|
enableIdsUsage = usage;
|
|
enableClassesUsage = usage;
|
|
} else if (usage) {
|
|
enableTagsUsage = usage.tags == null ? true : usage.tags;
|
|
enableIdsUsage = usage.ids == null ? true : usage.ids;
|
|
enableClassesUsage = usage.classes == null ? true : usage.classes;
|
|
forceUsageDeoptimized = usage.force == null ? false : usage.force;
|
|
}
|
|
|
|
let deoptimized = false;
|
|
|
|
return {
|
|
element: {
|
|
enter: (node, parentNode) => {
|
|
// detect deoptimisations
|
|
if (hasScripts(node)) {
|
|
deoptimized = true;
|
|
}
|
|
|
|
// collect tags, ids and classes usage
|
|
tagsUsage.add(node.name);
|
|
if (node.attributes.id != null) {
|
|
idsUsage.add(node.attributes.id);
|
|
}
|
|
if (node.attributes.class != null) {
|
|
for (const className of node.attributes.class.split(/\s+/)) {
|
|
classesUsage.add(className);
|
|
}
|
|
}
|
|
// collect style elements or elements with style attribute
|
|
if (node.name === 'style' && node.children.length !== 0) {
|
|
styleElements.set(node, parentNode);
|
|
} else if (node.attributes.style != null) {
|
|
elementsWithStyleAttributes.push(node);
|
|
}
|
|
},
|
|
},
|
|
|
|
root: {
|
|
exit: () => {
|
|
/** @type {csso.Usage} */
|
|
const cssoUsage = {};
|
|
if (!deoptimized || forceUsageDeoptimized) {
|
|
if (enableTagsUsage) {
|
|
cssoUsage.tags = Array.from(tagsUsage);
|
|
}
|
|
if (enableIdsUsage) {
|
|
cssoUsage.ids = Array.from(idsUsage);
|
|
}
|
|
if (enableClassesUsage) {
|
|
cssoUsage.classes = Array.from(classesUsage);
|
|
}
|
|
}
|
|
// minify style elements
|
|
for (const [styleNode, styleNodeParent] of styleElements.entries()) {
|
|
if (
|
|
styleNode.children[0].type === 'text' ||
|
|
styleNode.children[0].type === 'cdata'
|
|
) {
|
|
const cssText = styleNode.children[0].value;
|
|
const minified = csso.minify(cssText, {
|
|
...params,
|
|
usage: cssoUsage,
|
|
}).css;
|
|
|
|
if (minified.length === 0) {
|
|
detachNodeFromParent(styleNode, styleNodeParent);
|
|
continue;
|
|
}
|
|
|
|
// preserve cdata if necessary
|
|
// TODO split cdata -> text optimisation into separate plugin
|
|
if (cssText.indexOf('>') >= 0 || cssText.indexOf('<') >= 0) {
|
|
styleNode.children[0].type = 'cdata';
|
|
styleNode.children[0].value = minified;
|
|
} else {
|
|
styleNode.children[0].type = 'text';
|
|
styleNode.children[0].value = minified;
|
|
}
|
|
}
|
|
}
|
|
// minify style attributes
|
|
for (const node of elementsWithStyleAttributes) {
|
|
// style attribute
|
|
const elemStyle = node.attributes.style;
|
|
node.attributes.style = csso.minifyBlock(elemStyle, {
|
|
...params,
|
|
}).css;
|
|
}
|
|
},
|
|
},
|
|
};
|
|
};
|