source: frontend/node_modules/webpack/lib/schemes/DataUriPlugin.js

/*
        MIT License http://www.opensource.org/licenses/mit-license.php
        Author Tobias Koppers @sokra
*/

"use strict";

const NormalModule = require("../NormalModule");
const { URIRegEx, decodeDataURI } = require("../util/dataURL");

/** @typedef {import("../Compiler")} Compiler */

const PLUGIN_NAME = "DataUriPlugin";

class DataUriPlugin {
        /**
         * Applies the plugin by registering its hooks on the compiler.
         * @param {Compiler} compiler the compiler instance
         * @returns {void}
         */
        apply(compiler) {
                compiler.hooks.compilation.tap(
                        PLUGIN_NAME,
                        (compilation, { normalModuleFactory }) => {
                                normalModuleFactory.hooks.resolveForScheme
                                        .for("data")
                                        .tap(PLUGIN_NAME, (resourceData, resolveData) => {
                                                const match = URIRegEx.exec(resourceData.resource);
                                                if (match) {
                                                        resourceData.data.mimetype = match[1] || "";
                                                        resourceData.data.parameters = match[2] || "";
                                                        resourceData.data.encoding = /** @type {"base64" | false} */ (
                                                                match[3] || false
                                                        );
                                                        resourceData.data.encodedContent = match[4] || "";
                                                }
                                                // Inherit the issuer's resolution context so any nested
                                                // dependencies discovered while parsing the data URI's body
                                                // (e.g. `url(...)` / `@import` inside an inline CSS data
                                                // URI) resolve relative to where the URI was referenced
                                                // from, instead of against the synthetic `data:.../` path
                                                // that `getContext("data:…")` would otherwise infer.
                                                if (
                                                        resourceData.context === undefined &&
                                                        resolveData.context !== undefined
                                                ) {
                                                        resourceData.context = resolveData.context;
                                                }
                                        });

                                NormalModule.getCompilationHooks(compilation)
                                        .readResourceForScheme.for("data")
                                        .tap(PLUGIN_NAME, (resource) => decodeDataURI(resource));
                        }
                );
        }
}

module.exports = DataUriPlugin;