GoToSocial/web/source/lib/split-css.js

/*
	GoToSocial
	Copyright (C) 2021-2022 GoToSocial Authors admin@gotosocial.org

	This program is free software: you can redistribute it and/or modify
	it under the terms of the GNU Affero General Public License as published by
	the Free Software Foundation, either version 3 of the License, or
	(at your option) any later version.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU Affero General Public License for more details.

	You should have received a copy of the GNU Affero General Public License
	along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

"use strict";

const fs = require("fs");
const path = require("path");

const {Writable} = require("stream");
const out = require("./output-path");

const fromRegex = /\/\* from (.+?) \*\//;
module.exports = function splitCSS(outputEmitter) {
	return function() {
		let chunks = [];
		return new Writable({
			write: function(chunk, encoding, next) {
				chunks.push(chunk);
				next();
			},

			final: function() {
				let stream = chunks.join("");
				let input;
				let content = [];
	
				function write() {
					if (content.length != 0) {
						if (input == undefined) {
							if (content[0].length != 0) {
								throw new Error("Got CSS content without filename, can't output: ", content);
							}
						} else {
							outputEmitter.emit("update", {type: "CSS", updates: [input]});
							fs.writeFileSync(out(input), content.join("\n"));
						}
						content = [];
					}
				}
	
				const cssDir = path.join(__dirname, "../css");
	
				stream.split("\n").forEach((line) => {
					if (line.startsWith("/* from")) {
						let found = fromRegex.exec(line);
						if (found != null) {
							write();
	
							let parts = path.parse(found[1]);
							if (path.relative(cssDir, path.join(process.cwd(), parts.dir)) == "") {
								input = parts.base;
							} else {
								// prefix filename with path
								let relative = path.relative(path.join(__dirname, "../"), path.join(process.cwd(), found[1]));
								input = relative.replace(/\//g, "-");
							}
						}
					} else {
						content.push(line);
					}
				});

				write();
			}
		});
	};
};