wasmPlugin.mjs

import path from 'node:path';
import fs from 'node:fs';

export const wasmPluginEsbuild = {
	name: 'wasm',
	setup(build) {
		// Resolve ".wasm" files to a path with a namespace
		build.onResolve({ filter: /\.wasm$/ }, args => {
			if (args.resolveDir === '') {
				return; // Ignore unresolvable paths
			}
			return {
				path: path.isAbsolute(args.path) ? args.path : path.join(args.resolveDir, args.path),
				namespace: 'wasm-binary',
			};
		});

		// Virtual modules in the "wasm-binary" namespace contain the
		// actual bytes of the WebAssembly file. This uses esbuild's
		// built-in "binary" loader instead of manually embedding the
		// binary data inside JavaScript code ourselves.
		build.onLoad({ filter: /.*/, namespace: 'wasm-binary' }, async args => ({
			contents: await fs.promises.readFile(args.path),
			loader: 'binary',
		}));
	},
};