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gitea-lugit-theme/tools/tasks/optimize-css.js

112 lines
4.4 KiB
JavaScript

import { join } from 'path';
import { Logger } from '../utils/logger.js';
import { readFileSync, readdirSync } from 'fs';
import * as csstree from 'css-tree';
import { writeFile } from 'fs/promises';
const logger = new Logger('build', 'info', 'brightMagenta');
function getcCssFiles(distPath, path) {
try {
return readdirSync(join(distPath, path))
.filter((fn) => fn.endsWith('.css') && !fn.endsWith('.min.css'))
.map((file) => ({
name: file.replace('.css', ''),
path: join(distPath, path, file),
}));
} catch (err) {
return [];
}
}
export async function optimizeCss(distPath, replace = true) {
// get the css files in the dist folder
const cssFiles = getcCssFiles(distPath, 'public/assets/css');
for (const file of cssFiles) {
logger.info(`Sanitizing ${file.name} css file`);
let usedCssVariables = [];
// read the css file
const cssContent = readFileSync(file.path, { encoding: 'utf-8' });
const ast = csstree.parse(cssContent, {});
// get the css variables used in the css file
csstree.walk(ast, (node) => {
if (node.type === 'Function' && node.name === 'var') {
// get the variable name
for (const child of node.children) {
if (child.type === 'Identifier') {
usedCssVariables.push(child.name);
}
}
}
// could also be that the variable is assigned to another variable
if (node.type === 'Declaration' && node.property.startsWith('--')) {
// check if its assigned to another variable
if(node.property.startsWith('--')) {
if (node.value && node.value.type === 'Function' && node.value.name === 'var') {
for (const child of node.value.children) {
if (child.type === 'Identifier') {
if (!usedCssVariables.includes(child.name)) {
usedCssVariables.push(child.name);
}
}
}
} else if (node.value && node.value.type === 'Raw' && node.value.value) {
const val = node.value.value.trimStart(); // var(--v-primary)
// if starts with var(, then its assigned to another variable or many variables, get everything that's inside
// var(...) using regex capturing
// get all varname groups
const matches = val.matchAll(/var\((?<varname>[^),\s]+)/g);
for (const match of matches) {
// get the varname group
const varname = match.groups?.varname;
if (varname) {
if (!usedCssVariables.includes(varname)) {
usedCssVariables.push(varname);
}
}
}
}
}
if (node.value.children) {
for (const child of node.value.children) {
if (child.type === 'Function' && child.name === 'var') {
for (const varChild of child.children) {
if (varChild.type === 'Identifier') {
usedCssVariables.push(varChild.name);
}
}
}
}
}
}
});
// walk to find all variable declarations and remove the unused ones
csstree.walk(ast, (node, item, list) => {
if (
node.type === 'Declaration' &&
(node.property.startsWith('--v-') || node.property.startsWith('--c-'))
) {
const variable = node.property;
if (!usedCssVariables.includes(variable)) {
list.remove(item);
}
}
});
const finalPath = replace ? file.path : file.path.replace('.css', '.min.css');
await writeFile(finalPath, csstree.generate(ast, { mode: 'safe' }));
}
}