add compress to builder

packages/kit/src/core/adapt/builder.js

@@ -1,3 +1,8 @@
+import glob from 'tiny-glob';
+import zlib from 'zlib';
+import { existsSync, statSync, createReadStream, createWriteStream } from 'fs';
+import { pipeline } from 'stream';
+import { promisify } from 'util';
 import { copy, rimraf, mkdirp } from '../../utils/filesystem.js';
 import { generate_manifest } from '../generate_manifest/index.js';
 
@@ -25,6 +30,30 @@ export function create_builder({ config, build_data, prerendered, log }) {
 		return true;
 	}
 
+	const pipe = promisify(pipeline);
+
+	/**
+	 * @param {string} file
+	 * @param {'gz' | 'br'} format
+	 */
+	async function compress_file(file, format = 'gz') {
+		const compress =
+			format == 'br'
+				? zlib.createBrotliCompress({
+						params: {
+							[zlib.constants.BROTLI_PARAM_MODE]: zlib.constants.BROTLI_MODE_TEXT,
+							[zlib.constants.BROTLI_PARAM_QUALITY]: zlib.constants.BROTLI_MAX_QUALITY,
+							[zlib.constants.BROTLI_PARAM_SIZE_HINT]: statSync(file).size
+						}
+				  })
+				: zlib.createGzip({ level: zlib.constants.Z_BEST_COMPRESSION });
+
+		const source = createReadStream(file);
+		const destination = createWriteStream(`${file}.${format}`);
+
+		await pipe(source, compress, destination);
+	}
+
 	return {
 		log,
 		rimraf,
@@ -151,6 +180,23 @@ export function create_builder({ config, build_data, prerendered, log }) {
 			);
 		},
 
+		async compress(directory) {
+			if (!existsSync(directory)) {
+				return;
+			}
+
+			const files = await glob('**/*.{html,js,json,css,svg,xml,wasm}', {
+				cwd: directory,
+				dot: true,
+				absolute: true,
+				filesOnly: true
+			});
+
+			await Promise.all(
+				files.map((file) => Promise.all([compress_file(file, 'gz'), compress_file(file, 'br')]))
+			);
+		},
+
 		async prerender() {
 			throw new Error(
 				'builder.prerender() has been removed. Prerendering now takes place in the build phase — see builder.prerender and builder.writePrerendered'

packages/kit/types/index.d.ts

@@ -80,6 +80,11 @@ export interface Builder {
 			replace?: Record<string, string>;
 		}
 	): string[];
+
+	/**
+	 * @param {string} directory A path to file that would be compress.
+	 */
+	compress(directory: string): void;
 }
 
 export interface Config {