source: frontend/node_modules/webpack/lib/BannerPlugin.js

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

"use strict";

const { ConcatSource } = require("webpack-sources");
const Compilation = require("./Compilation");
const ModuleFilenameHelpers = require("./ModuleFilenameHelpers");
const Template = require("./Template");

/** @typedef {import("webpack-sources").Source} Source */
/** @typedef {import("../declarations/plugins/BannerPlugin").BannerPluginArgument} BannerPluginArgument */
/** @typedef {import("../declarations/plugins/BannerPlugin").BannerPluginOptions} BannerPluginOptions */
/** @typedef {import("./Compilation").PathDataChunk} PathDataChunk */
/** @typedef {import("./Compiler")} Compiler */
/** @typedef {import("./Chunk")} Chunk */

/** @typedef {(data: { hash?: string, chunk: Chunk, filename: string }) => string} BannerFunction */

/**
 * Wraps banner text in a JavaScript block comment, preserving multi-line
 * formatting and escaping accidental comment terminators.
 * @param {string} str string to wrap
 * @returns {string} wrapped string
 */
const wrapComment = (str) => {
        if (!str.includes("\n")) {
                return Template.toComment(str);
        }
        return `/*!\n * ${str
                .replace(/\*\//g, "* /")
                .split("\n")
                .join("\n * ")
                .replace(/\s+\n/g, "\n")
                .trimEnd()}\n */`;
};

const PLUGIN_NAME = "BannerPlugin";

/**
 * Prepends or appends banner text to emitted assets that match the configured
 * file filters.
 */
class BannerPlugin {
        /**
         * Normalizes banner options and compiles the configured banner source into a
         * function that can render per-asset banner text.
         * @param {BannerPluginArgument} options options object
         */
        constructor(options) {
                if (typeof options === "string" || typeof options === "function") {
                        options = {
                                banner: options
                        };
                }

                /** @type {BannerPluginOptions} */
                this.options = options;

                const bannerOption = options.banner;
                if (typeof bannerOption === "function") {
                        const getBanner = bannerOption;
                        /** @type {BannerFunction} */
                        this.banner = this.options.raw
                                ? getBanner
                                : /** @type {BannerFunction} */ (data) => wrapComment(getBanner(data));
                } else {
                        const banner = this.options.raw
                                ? bannerOption
                                : wrapComment(bannerOption);
                        /** @type {BannerFunction} */
                        this.banner = () => banner;
                }
        }

        /**
         * Validates the configured options and injects rendered banner comments into
         * matching compilation assets at the configured process-assets stage.
         * @param {Compiler} compiler the compiler instance
         * @returns {void}
         */
        apply(compiler) {
                compiler.hooks.validate.tap(PLUGIN_NAME, () => {
                        compiler.validate(
                                () => require("../schemas/plugins/BannerPlugin.json"),
                                this.options,
                                {
                                        name: "Banner Plugin",
                                        baseDataPath: "options"
                                },
                                (options) => require("../schemas/plugins/BannerPlugin.check")(options)
                        );
                });
                const options = this.options;
                const banner = this.banner;
                const matchObject = ModuleFilenameHelpers.matchObject.bind(
                        undefined,
                        options
                );
                /** @type {WeakMap<Source, { source: ConcatSource, comment: string }>} */
                const cache = new WeakMap();
                const stage =
                        this.options.stage || Compilation.PROCESS_ASSETS_STAGE_ADDITIONS;

                compiler.hooks.compilation.tap(PLUGIN_NAME, (compilation) => {
                        compilation.hooks.processAssets.tap({ name: PLUGIN_NAME, stage }, () => {
                                for (const chunk of compilation.chunks) {
                                        if (options.entryOnly && !chunk.canBeInitial()) {
                                                continue;
                                        }

                                        for (const file of chunk.files) {
                                                if (!matchObject(file)) {
                                                        continue;
                                                }

                                                /** @type {PathDataChunk} */
                                                const data = { chunk, filename: file };

                                                const comment = compilation.getPath(
                                                        /** @type {string | import("./TemplatedPathPlugin").TemplatePathFn<PathDataChunk>} */
                                                        (banner),
                                                        data
                                                );

                                                compilation.updateAsset(file, (old) => {
                                                        const cached = cache.get(old);
                                                        if (!cached || cached.comment !== comment) {
                                                                const source = options.footer
                                                                        ? new ConcatSource(old, "\n", comment)
                                                                        : new ConcatSource(comment, "\n", old);
                                                                cache.set(old, { source, comment });
                                                                return source;
                                                        }
                                                        return cached.source;
                                                });
                                        }
                                }
                        });
                });
        }
}

module.exports = BannerPlugin;