etherpad-lite/src/node/hooks/express/static.ts

import type { MapArrayType } from "../../types/MapType";
import type { PartType } from "../../types/PartType";

const fs = require("fs").promises;
const minify = require("../../utils/Minify");
const path = require("path");
const plugins = require("../../../static/js/pluginfw/plugin_defs");
const settings = require("../../utils/Settings");
import CachingMiddleware from "../../utils/caching_middleware";
const Yajsml = require("etherpad-yajsml");

// Rewrite tar to include modules with no extensions and proper rooted paths.
const getTar = async () => {
	const prefixLocalLibraryPath = (path: string) => {
		if (path.charAt(0) === "$") {
			return path.slice(1);
		} else {
			return `ep_etherpad-lite/static/js/${path}`;
		}
	};

	const tarJson = await fs.readFile(
		path.join(settings.root, "src/node/utils/tar.json"),
		"utf8",
	);
	const tar: MapArrayType<string[]> = {};
	for (const [key, relativeFiles] of Object.entries(JSON.parse(tarJson)) as [
		string,
		string[],
	][]) {
		const files = relativeFiles.map(prefixLocalLibraryPath);
		tar[prefixLocalLibraryPath(key)] = files
			.concat(files.map((p) => p.replace(/\.js$/, "")))
			.concat(files.map((p) => `${p.replace(/\.js$/, "")}/index.js`));
	}
	return tar;
};

exports.expressPreSession = async (hookName: string, { app }: any) => {
	// Cache both minified and static.
	const assetCache = new CachingMiddleware();
	// Cache static assets
	app.all(/\/js\/(.*)/, assetCache.handle.bind(assetCache));
	app.all(/\/css\/(.*)/, assetCache.handle.bind(assetCache));

	// Minify will serve static files compressed (minify enabled). It also has
	// file-specific hacks for ace/require-kernel/etc.
	app.all("/static/:filename(*)", minify.minify);

	// Setup middleware that will package JavaScript files served by minify for
	// CommonJS loader on the client-side.
	// Hostname "invalid.invalid" is a dummy value to allow parsing as a URI.
	const jsServer = new Yajsml.Server({
		rootPath: "javascripts/src/",
		rootURI: "http://invalid.invalid/static/js/",
		libraryPath: "javascripts/lib/",
		libraryURI: "http://invalid.invalid/static/plugins/",
		requestURIs: minify.requestURIs, // Loop-back is causing problems, this is a workaround.
	});

	const StaticAssociator = Yajsml.associators.StaticAssociator;
	const associations = Yajsml.associators.associationsForSimpleMapping(
		await getTar(),
	);
	const associator = new StaticAssociator(associations);
	jsServer.setAssociator(associator);

	app.use(jsServer.handle.bind(jsServer));

	// serve plugin definitions
	// not very static, but served here so that client can do
	// require("pluginfw/static/js/plugin-definitions.js");
	app.get(
		"/pluginfw/plugin-definitions.json",
		(req: any, res: any, next: Function) => {
			const clientParts = plugins.parts.filter(
				(part: PartType) => part.client_hooks != null,
			);
			const clientPlugins: MapArrayType<string> = {};
			for (const name of new Set(
				clientParts.map((part: PartType) => part.plugin),
			)) {
				// @ts-ignore
				clientPlugins[name] = { ...plugins.plugins[name] };
				// @ts-ignore
				delete clientPlugins[name].package;
			}
			res.setHeader("Content-Type", "application/json; charset=utf-8");
			res.setHeader("Cache-Control", `public, max-age=${settings.maxAge}`);
			res.write(JSON.stringify({ plugins: clientPlugins, parts: clientParts }));
			res.end();
		},
	);
};