webpack/lib/node/ReadFileCompileWasmPlugin.js

Packs ECMAScript/CommonJs/AMD modules for the browser. Allows you to split your codebase into multiple bundles, which can be loaded on demand. Supports loaders to preprocess files, i.e. json, jsx, es7, css, less, ... and your custom stuff.

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

"use strict";

const { WEBASSEMBLY_MODULE_TYPE_SYNC } = require("../ModuleTypeConstants");
const RuntimeGlobals = require("../RuntimeGlobals");
const Template = require("../Template");
const WasmChunkLoadingRuntimeModule = require("../wasm-sync/WasmChunkLoadingRuntimeModule");

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

/**
 * @typedef {object} ReadFileCompileWasmPluginOptions
 * @property {boolean} [mangleImports] mangle imports
 */

// TODO webpack 6 remove

class ReadFileCompileWasmPlugin {
	/**
	 * @param {ReadFileCompileWasmPluginOptions} [options] options object
	 */
	constructor(options = {}) {
		this.options = options;
	}

	/**
	 * Apply the plugin
	 * @param {Compiler} compiler the compiler instance
	 * @returns {void}
	 */
	apply(compiler) {
		compiler.hooks.thisCompilation.tap(
			"ReadFileCompileWasmPlugin",
			compilation => {
				const globalWasmLoading = compilation.outputOptions.wasmLoading;
				/**
				 * @param {Chunk} chunk chunk
				 * @returns {boolean} true, when wasm loading is enabled for the chunk
				 */
				const isEnabledForChunk = chunk => {
					const options = chunk.getEntryOptions();
					const wasmLoading =
						options && options.wasmLoading !== undefined
							? options.wasmLoading
							: globalWasmLoading;
					return wasmLoading === "async-node";
				};
				/**
				 * @param {string} path path to wasm file
				 * @returns {string} generated code to load the wasm file
				 */
				const generateLoadBinaryCode = path =>
					Template.asString([
						"new Promise(function (resolve, reject) {",
						Template.indent([
							"var { readFile } = require('fs');",
							"var { join } = require('path');",
							"",
							"try {",
							Template.indent([
								`readFile(join(__dirname, ${path}), function(err, buffer){`,
								Template.indent([
									"if (err) return reject(err);",
									"",
									"// Fake fetch response",
									"resolve({",
									Template.indent(["arrayBuffer() { return buffer; }"]),
									"});"
								]),
								"});"
							]),
							"} catch (err) { reject(err); }"
						]),
						"})"
					]);

				compilation.hooks.runtimeRequirementInTree
					.for(RuntimeGlobals.ensureChunkHandlers)
					.tap("ReadFileCompileWasmPlugin", (chunk, set) => {
						if (!isEnabledForChunk(chunk)) return;
						const chunkGraph = compilation.chunkGraph;
						if (
							!chunkGraph.hasModuleInGraph(
								chunk,
								m => m.type === WEBASSEMBLY_MODULE_TYPE_SYNC
							)
						) {
							return;
						}
						set.add(RuntimeGlobals.moduleCache);
						compilation.addRuntimeModule(
							chunk,
							new WasmChunkLoadingRuntimeModule({
								generateLoadBinaryCode,
								supportsStreaming: false,
								mangleImports: this.options.mangleImports,
								runtimeRequirements: set
							})
						);
					});
			}
		);
	}
}

module.exports = ReadFileCompileWasmPlugin;