purgecss-webpack-plugin/lib/purgecss-webpack-plugin.esm.js

PurgeCSS plugin for webpack - Remove unused css

import * as fs from 'fs';
import * as path from 'path';
import { PurgeCSS, defaultOptions } from 'purgecss';
import { sources } from 'webpack';

const styleExtensions = [".css", ".scss", ".styl", ".sass", ".less"];
const pluginName = "PurgeCSS";
/**
 * Get the filename without ?hash
 *
 * @param fileName - file name
 */
function getFormattedFilename(fileName) {
    if (fileName.includes("?")) {
        return fileName.split("?").slice(0, -1).join("");
    }
    return fileName;
}
/**
 * Returns true if the filename is of types of one of the specified extensions
 *
 * @param filename - file name
 * @param extensions - extensions
 */
function isFileOfTypes(filename, extensions) {
    const extension = path.extname(getFormattedFilename(filename));
    return extensions.includes(extension);
}
function getPurgeCSSOptions(pluginOptions, filesToSearch, asset, fileName, sourceMap) {
    const options = {
        ...defaultOptions,
        ...pluginOptions,
        content: filesToSearch,
        css: [
            {
                raw: asset.source().toString(),
            },
        ],
    };
    if (typeof options.safelist === "function") {
        options.safelist = options.safelist();
    }
    if (typeof options.blocklist === "function") {
        options.blocklist = options.blocklist();
    }
    return {
        content: options.content,
        css: options.css,
        defaultExtractor: options.defaultExtractor,
        extractors: options.extractors,
        fontFace: options.fontFace,
        keyframes: options.keyframes,
        output: options.output,
        rejected: options.rejected,
        variables: options.variables,
        safelist: options.safelist,
        blocklist: options.blocklist,
        sourceMap: sourceMap ? { inline: false, to: fileName } : false,
    };
}
/**
 * Create the Source instance result of PurgeCSS
 *
 * @param name - asset name
 * @param asset - webpack asset
 * @param purgeResult - result of PurgeCSS purge method
 * @param sourceMap - wether sourceMap is enabled
 * @returns the new Source
 */
function createSource(name, asset, purgeResult, sourceMap) {
    if (!sourceMap || !purgeResult.sourceMap) {
        return new sources.RawSource(purgeResult.css);
    }
    const { source, map } = asset.sourceAndMap();
    return new sources.SourceMapSource(purgeResult.css, name, purgeResult.sourceMap, source.toString(), map, false);
}
/**
 * @public
 */
class PurgeCSSPlugin {
    constructor(options) {
        this.purgedStats = {};
        this.options = options;
    }
    apply(compiler) {
        compiler.hooks.compilation.tap(pluginName, this.initializePlugin.bind(this));
    }
    initializePlugin(compilation) {
        compilation.hooks.additionalAssets.tapPromise(pluginName, async () => {
            let configFileOptions;
            try {
                const t = path.resolve(process.cwd(), "purgecss.config.js");
                configFileOptions = await import(t);
            }
            catch {
                // no config file present
            }
            this.options = {
                ...(configFileOptions ? configFileOptions : {}),
                ...this.options,
            };
            const entryPaths = typeof this.options.paths === "function"
                ? this.options.paths()
                : this.options.paths;
            entryPaths.forEach((p) => {
                if (!fs.existsSync(p))
                    throw new Error(`Path ${p} does not exist.`);
            });
            return this.runPluginHook(compilation, entryPaths);
        });
    }
    async runPluginHook(compilation, entryPaths) {
        const assetsFromCompilation = Object.entries(compilation.assets).filter(([name]) => {
            return isFileOfTypes(name, [".css"]);
        });
        for (const chunk of compilation.chunks) {
            const assetsToPurge = assetsFromCompilation.filter(([name]) => {
                if (this.options.only) {
                    if (!this.options.only.some((only) => name.includes(only))) {
                        return false;
                    }
                }
                return chunk.files.has(name);
            });
            for (const [name, asset] of assetsToPurge) {
                const filesToSearch = entryPaths.filter((v) => !styleExtensions.some((ext) => v.endsWith(ext)));
                const sourceMapEnabled = !!compilation.compiler.options.devtool;
                const purgeCSSOptions = getPurgeCSSOptions(this.options, filesToSearch, asset, name, sourceMapEnabled);
                const purgecss = await new PurgeCSS().purge(purgeCSSOptions);
                const purged = purgecss[0];
                if (purged.rejected) {
                    this.purgedStats[name] = purged.rejected;
                }
                compilation.updateAsset(name, createSource(name, asset, purged, sourceMapEnabled));
            }
        }
    }
}

export { PurgeCSSPlugin };