source: frontend/node_modules/webpack/lib/wasm/EnableWasmLoadingPlugin.js

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

"use strict";

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

/** @typedef {Set<WasmLoadingType>} WasmLoadingTypes */

/** @type {WeakMap<Compiler, Set<WasmLoadingType>>} */
const enabledTypes = new WeakMap();

/**
 * Returns the set of wasm loading backends that have already been enabled for
 * the compiler.
 * @param {Compiler} compiler compiler instance
 * @returns {WasmLoadingTypes} enabled types
 */
const getEnabledTypes = (compiler) => {
        let set = enabledTypes.get(compiler);
        if (set === undefined) {
                /** @type {WasmLoadingTypes} */
                set = new Set();
                enabledTypes.set(compiler, set);
        }
        return set;
};

/**
 * Validates and enables named wasm loading backends by applying the plugin
 * implementations that provide their runtime support.
 */
class EnableWasmLoadingPlugin {
        /**
         * Stores the wasm loading backend name that should be enabled for the
         * compiler.
         * @param {WasmLoadingType} type library type that should be available
         */
        constructor(type) {
                /** @type {WasmLoadingType} */
                this.type = type;
        }

        /**
         * Marks a custom or built-in wasm loading type as enabled for the compiler
         * without applying additional built-in behavior.
         * @param {Compiler} compiler the compiler instance
         * @param {WasmLoadingType} type type of library
         * @returns {void}
         */
        static setEnabled(compiler, type) {
                getEnabledTypes(compiler).add(type);
        }

        /**
         * Verifies that a wasm loading type has been enabled before code generation
         * attempts to use it.
         * @param {Compiler} compiler the compiler instance
         * @param {WasmLoadingType} type type of library
         * @returns {void}
         */
        static checkEnabled(compiler, type) {
                if (!getEnabledTypes(compiler).has(type)) {
                        throw new Error(
                                `Library type "${type}" is not enabled. ` +
                                        "EnableWasmLoadingPlugin need to be used to enable this type of wasm loading. " +
                                        'This usually happens through the "output.enabledWasmLoadingTypes" option. ' +
                                        'If you are using a function as entry which sets "wasmLoading", you need to add all potential library types to "output.enabledWasmLoadingTypes". ' +
                                        `These types are enabled: ${[...getEnabledTypes(compiler)].join(", ")}`
                        );
                }
        }

        /**
         * Enables the requested wasm loading backend once and applies the
         * environment-specific plugins that provide its parser, generator, and
         * runtime support.
         * @param {Compiler} compiler the compiler instance
         * @returns {void}
         */
        apply(compiler) {
                const { type } = this;

                // Only enable once
                const enabled = getEnabledTypes(compiler);
                if (enabled.has(type)) return;
                enabled.add(type);

                if (typeof type === "string") {
                        switch (type) {
                                case "fetch": {
                                        if (compiler.options.experiments.syncWebAssembly) {
                                                const FetchCompileWasmPlugin = require("../web/FetchCompileWasmPlugin");

                                                new FetchCompileWasmPlugin({
                                                        mangleImports: compiler.options.optimization.mangleWasmImports
                                                }).apply(compiler);
                                        }

                                        if (compiler.options.experiments.asyncWebAssembly) {
                                                const FetchCompileAsyncWasmPlugin = require("../web/FetchCompileAsyncWasmPlugin");

                                                new FetchCompileAsyncWasmPlugin().apply(compiler);
                                        }

                                        break;
                                }
                                case "async-node": {
                                        if (compiler.options.experiments.syncWebAssembly) {
                                                const ReadFileCompileWasmPlugin = require("../node/ReadFileCompileWasmPlugin");

                                                new ReadFileCompileWasmPlugin({
                                                        mangleImports: compiler.options.optimization.mangleWasmImports,
                                                        import:
                                                                compiler.options.output.module &&
                                                                compiler.options.output.environment.dynamicImport
                                                }).apply(compiler);
                                        }

                                        if (compiler.options.experiments.asyncWebAssembly) {
                                                const ReadFileCompileAsyncWasmPlugin = require("../node/ReadFileCompileAsyncWasmPlugin");

                                                new ReadFileCompileAsyncWasmPlugin({
                                                        import:
                                                                compiler.options.output.module &&
                                                                compiler.options.output.environment.dynamicImport
                                                }).apply(compiler);
                                        }

                                        break;
                                }
                                case "universal": {
                                        if (compiler.options.experiments.syncWebAssembly) {
                                                throw new Error(
                                                        "Universal wasm loading type is only supported by asynchronous web assembly."
                                                );
                                        }

                                        if (compiler.options.experiments.asyncWebAssembly) {
                                                const UniversalCompileAsyncWasmPlugin = require("../wasm-async/UniversalCompileAsyncWasmPlugin");

                                                new UniversalCompileAsyncWasmPlugin().apply(compiler);
                                        }
                                        break;
                                }
                                default:
                                        throw new Error(`Unsupported wasm loading type ${type}.
Plugins which provide custom wasm loading types must call EnableWasmLoadingPlugin.setEnabled(compiler, type) to disable this error.`);
                        }
                } else {
                        // TODO support plugin instances here
                        // apply them to the compiler
                }
        }
}

module.exports = EnableWasmLoadingPlugin;