kmx.io/prism.js

diff --git a/gulpfile.js b/gulpfile.js
deleted file mode 100644
index 9c09a76..0000000
--- a/gulpfile.js
+++ /dev/null
@@ -1,272 +0,0 @@
-const { src, dest, series, parallel, watch } = require('gulp');
-
-const rename = require('gulp-rename');
-const uglify = require('gulp-uglify');
-const header = require('gulp-header');
-const concat = require('gulp-concat');
-const replace = require('gulp-replace');
-const pump = require('pump');
-const util = require('util');
-const fs = require('fs');
-const simpleGit = require('simple-git');
-const shelljs = require('shelljs');
-
-const paths = {
-	componentsFile: 'components.json',
-	componentsFileJS: 'components.js',
-	components: ['components/**/*.js', '!components/index.js', '!components/**/*.min.js'],
-	main: [
-		'components/prism-core.js',
-		'components/prism-markup.js',
-		'components/prism-css.js',
-		'components/prism-clike.js',
-		'components/prism-javascript.js',
-		'plugins/file-highlight/prism-file-highlight.js'
-	],
-	plugins: ['plugins/**/*.js', '!plugins/**/*.min.js'],
-	showLanguagePlugin: 'plugins/show-language/prism-show-language.js',
-	autoloaderPlugin: 'plugins/autoloader/prism-autoloader.js',
-	changelog: 'CHANGELOG.md'
-};
-
-const componentsPromise = new Promise((resolve, reject) => {
-	fs.readFile(paths.componentsFile, {
-		encoding: 'utf-8'
-	}, (err, data) => {
-		if (!err) {
-			resolve(JSON.parse(data));
-		} else {
-			reject(err);
-		}
-	});
-});
-
-function inlineRegexSource() {
-	return replace(
-		/\/((?:[^\n\r[\\\/]|\\.|\[(?:[^\n\r\\\]]|\\.)*\])*)\/\.source\b/g,
-		(m, source) => {
-			// escape backslashes
-			source = source.replace(/\\/g, '\\\\');
-			// escape single quotes
-			source = source.replace(/'/g, "\\'");
-			// unescape characters like \\n and \\t to \n and \t
-			source = source.replace(/(^|[^\\])\\\\([nrt0])/g, '$1\\$2');
-			// wrap source in single quotes
-			return "'" + source + "'";
-		}
-	);
-}
-
-function minifyJS() {
-	return [
-		inlineRegexSource(),
-		uglify()
-	];
-}
-
-
-function minifyComponents(cb) {
-	pump([src(paths.components), ...minifyJS(), rename({ suffix: '.min' }), dest('components')], cb);
-}
-function minifyPlugins(cb) {
-	pump([src(paths.plugins), ...minifyJS(), rename({ suffix: '.min' }), dest('plugins')], cb);
-}
-function build(cb) {
-	pump([src(paths.main), header(`
-/* **********************************************
-     Begin <%= file.relative %>
-********************************************** */
-
-`), concat('prism.js'), dest('./')], cb);
-}
-
-async function componentsJsonToJs() {
-	const data = await componentsPromise;
-	const js = `var components = ${JSON.stringify(data)};
-if (typeof module !== 'undefined' && module.exports) { module.exports = components; }`;
-	return util.promisify(fs.writeFile)(paths.componentsFileJS, js);
-}
-
-function watchComponentsAndPlugins() {
-	watch(paths.components, parallel(minifyComponents, build));
-	watch(paths.plugins, parallel(minifyPlugins, build));
-}
-
-async function languagePlugins() {
-	const data = await componentsPromise;
-	const languagesMap = {};
-	const dependenciesMap = {};
-	const aliasMap = {};
-
-	/**
-	 * Tries to guess the name of a language given its id.
-	 *
-	 * From `prism-show-language.js`.
-	 *
-	 * @param {string} id The language id.
-	 * @returns {string}
-	 */
-	function guessTitle(id) {
-		if (!id) {
-			return id;
-		}
-		return (id.substring(0, 1).toUpperCase() + id.substring(1)).replace(/s(?=cript)/, 'S');
-	}
-
-	/**
-	 * @param {string} key
-	 * @param {string} title
-	 */
-	function addLanguageTitle(key, title) {
-		if (!languagesMap[key] && guessTitle(key) !== title) {
-			languagesMap[key] = title;
-		}
-	}
-
-	for (const id in data.languages) {
-		if (id !== 'meta') {
-			const language = data.languages[id];
-			const title = language.displayTitle || language.title;
-
-			addLanguageTitle(id, title);
-
-			for (const name in language.aliasTitles) {
-				addLanguageTitle(name, language.aliasTitles[name]);
-			}
-
-			if (language.alias) {
-				if (typeof language.alias === 'string') {
-					aliasMap[language.alias] = id;
-					addLanguageTitle(language.alias, title);
-				} else {
-					language.alias.forEach(function (alias) {
-						aliasMap[alias] = id;
-						addLanguageTitle(alias, title);
-					});
-				}
-			}
-
-			if (language.require) {
-				dependenciesMap[id] = language.require;
-			}
-		}
-	}
-
-	function formattedStringify(json) {
-		return JSON.stringify(json, null, '\t').replace(/\n/g, '\n\t');
-	}
-
-	const jsonLanguagesMap = formattedStringify(languagesMap);
-	const jsonDependenciesMap = formattedStringify(dependenciesMap);
-	const jsonAliasMap = formattedStringify(aliasMap);
-
-	const tasks = [
-		{
-			plugin: paths.showLanguagePlugin,
-			maps: { languages: jsonLanguagesMap}
-		},
-		{
-			plugin: paths.autoloaderPlugin,
-			maps: { aliases: jsonAliasMap, dependencies: jsonDependenciesMap }
-		}
-	];
-
-	// TODO: Use `Promise.allSettled` (https://github.com/tc39/proposal-promise-allSettled)
-	const taskResults = await Promise.all(tasks.map(task => new Promise((resolve, reject) => {
-		const stream = src(task.plugin)
-			.pipe(replace(
-				/\/\*(\w+)_placeholder\[\*\/[\s\S]*?\/\*\]\*\//g,
-				(m, mapName) => `/*${mapName}_placeholder[*/${task.maps[mapName]}/*]*/`
-			))
-			.pipe(dest(task.plugin.substring(0, task.plugin.lastIndexOf('/'))));
-
-		stream.on('error', reject);
-		stream.on('end', resolve);
-	}).then(
-		/** @type {<T>(value: T) => {status: 'fulfilled', value: T}} */ value => ({status: 'fulfilled', value}),
-		/** @type {<T>(error: T) => {status: 'rejected', reason: T}} */ error => ({status: 'rejected', reason: error}),
-	)));
-
-	const rejectedTasks = taskResults.filter(/** @return {r is {status: 'rejected', reason: any}} */ r => r.status === 'rejected');
-	if (rejectedTasks.length > 0) {
-		throw rejectedTasks.map(r => r.reason);
-	}
-}
-
-const ISSUE_RE = /#(\d+)(?![\d\]])/g;
-const ISSUE_SUB = '[#$1](https://github.com/PrismJS/prism/issues/$1)';
-
-function linkify(cb) {
-	return pump([
-		src(paths.changelog),
-		replace(ISSUE_RE, ISSUE_SUB),
-		replace(
-			/\[[\da-f]+(?:, *[\da-f]+)*\]/g,
-			m => m.replace(/([\da-f]{7})[\da-f]*/g, '[`$1`](https://github.com/PrismJS/prism/commit/$1)')
-		),
-		dest('.')
-	], cb);
-}
-
-const COMMIT_RE = /^([\da-z]{8})\s(.*)/;
-
-function changes(cb) {
-	const tag = shelljs.exec('git describe --abbrev=0 --tags', { silent: true }).stdout;
-	const commits = shelljs
-		.exec(
-			`git log ${tag.trim()}..HEAD --oneline`,
-			{ silent: true }
-		)
-		.stdout.split('\n')
-		.map(line => line.trim())
-		.filter(line => line !== '')
-		.map(line => {
-			const [,hash, msg] = COMMIT_RE.exec(line);
-			return `* ${msg.replace(ISSUE_RE, ISSUE_SUB)} [\`${hash}\`](https://github.com/PrismJS/prism/commit/${hash})`
-		})
-		.join('\n');
-
-	const changes = `## Unreleased
-
-${commits}
-
-### New components
-
-### Updated components
-
-### Updated plugins
-
-### Updated themes
-
-### Other changes
-
-* __Website__`;
-
-	console.log(changes);
-	cb();
-}
-
-const components = minifyComponents;
-const plugins = series(languagePlugins, minifyPlugins);
-
-function gitChanges(cb) {
-	const git = simpleGit(__dirname);
-
-	git.status((err, res) => {
-		if (err) {
-			cb(new Error(`Something went wrong!\n${err}`));
-		} else if (res.files.length > 0) {
-			console.log(res);
-			cb(new Error('There are changes in the file system. Did you forget to run gulp?'));
-		} else {
-			cb();
-		}
-	});
-}
-
-
-exports.watch = watchComponentsAndPlugins;
-exports.default = parallel(components, plugins, componentsJsonToJs, build);
-exports.premerge = gitChanges;
-exports.linkify = linkify;
-exports.changes = changes;
diff --git a/gulpfile.js/changelog.js b/gulpfile.js/changelog.js
new file mode 100644
index 0000000..1fb9fe1
--- /dev/null
+++ b/gulpfile.js/changelog.js
@@ -0,0 +1,381 @@
+"use strict";
+
+const { src, dest } = require('gulp');
+
+const replace = require('gulp-replace');
+const pump = require('pump');
+const git = require('simple-git/promise')(__dirname);
+
+const { changelog } = require('./paths');
+
+
+const ISSUE_RE = /#(\d+)(?![\d\]])/g;
+const ISSUE_SUB = '[#$1](https://github.com/PrismJS/prism/issues/$1)';
+
+function linkify(cb) {
+	return pump([
+		src(changelog),
+		replace(ISSUE_RE, ISSUE_SUB),
+		replace(
+			/\[[\da-f]+(?:, *[\da-f]+)*\]/g,
+			m => m.replace(/([\da-f]{7})[\da-f]*/g, '[`$1`](https://github.com/PrismJS/prism/commit/$1)')
+		),
+		dest('.')
+	], cb);
+}
+
+/**
+ * Creates an array which iterates its items in the order given by `compareFn`.
+ *
+ * The array may not be sorted at all times.
+ *
+ * @param {(a: T, b: T) => number} compareFn
+ * @returns {T[]}
+ * @template T
+ */
+function createSortedArray(compareFn) {
+	/** @type {T[]} */
+	const a = [];
+
+	a['sort'] = function () {
+		return Array.prototype.sort.call(this, compareFn);
+	};
+	a[Symbol.iterator] = function () {
+		return this.slice().sort(compareFn)[Symbol.iterator]();
+	};
+
+	return a;
+}
+
+/**
+ * Parses the given log line and adds the list of the changed files to the output.
+ *
+ * @param {string} line A one-liner log line consisting of the commit hash and the commit message.
+ * @returns {Promise<CommitInfo>}
+ *
+ * @typedef {{ message: string, hash: string, changes: CommitChange[] }} CommitInfo
+ * @typedef {{ file: string, mode: ChangeMode }} CommitChange
+ * @typedef {"A" | "C" | "D" | "M" | "R" | "T" | "U" | "X" | "B"} ChangeMode
+ */
+async function getCommitInfo(line) {
+	const [, hash, message] = /^([a-f\d]+)\s+(.*)$/i.exec(line);
+
+	/* The output looks like this:
+	 *
+	 * M       components.js
+	 * M       components.json
+	 *
+	 * or nothing for e.g. reverts.
+	 */
+	const output = await git.raw(['diff-tree', '--no-commit-id', '--name-status', '-r', hash]);
+
+	const changes = !output ? [] : output.trim().split(/\n/g).map(line => {
+		const [, mode, file] = /(\w)\s+(.+)/.exec(line);
+		return { mode: /** @type {ChangeMode} */ (mode), file };
+	});
+
+	return { hash, message, changes };
+}
+
+/**
+ * Parses the output of `git log` with the given revision range.
+ *
+ * @param {string | Promise<string>} range The revision range in which the log will be parsed.
+ * @returns {Promise<CommitInfo[]>}
+ */
+async function getLog(range) {
+	/* The output looks like this:
+	*
+	* bfbe4464 Invoke `callback` after `after-highlight` hook (#1588)
+	* b41fb8f1 Fixes regex for JS examples (#1591)
+	*/
+	const output = await git.raw(['log', await Promise.resolve(range), '--oneline']);
+
+	if (output) {
+		const commits = output.trim().split(/\n/g);
+		return Promise.all(commits.map(getCommitInfo));
+	} else {
+		return [];
+	}
+}
+
+const revisionRanges = {
+	nextRelease: git.raw(['describe', '--abbrev=0', '--tags']).then(res => `${res.trim()}..HEAD`)
+};
+const strCompare = (a, b) => a.localeCompare(b, 'en');
+
+async function changes() {
+	const { languages, plugins } = require('../components');
+
+	const infos = await getLog(revisionRanges.nextRelease);
+
+	const entries = {
+		'TODO:': {},
+		'New components': {
+			['']: createSortedArray(strCompare)
+		},
+		'Updated components': {},
+		'Updated plugins': {},
+		'Updated themes': {},
+		'Other': {},
+	};
+	/**
+	 *
+	 * @param {string} category
+	 * @param {string | { message: string, hash: string }} info
+	 */
+	function addEntry(category, info) {
+		const path = category.split(/\s*>>\s*/g);
+		if (path[path.length - 1] !== '') {
+			path.push('');
+		}
+
+		let current = entries;
+		for (const key of path) {
+			if (key) {
+				current = current[key] = current[key] || {};
+			} else {
+				(current[key] = current[key] || []).push(info);
+			}
+		}
+	}
+
+
+	/** @param {CommitChange} change */
+	function notGenerated(change) {
+		return !change.file.endsWith('.min.js') && ['prism.js', 'components.js', 'package-lock.json'].indexOf(change.file) === -1;
+	}
+	/** @param {CommitChange} change */
+	function notPartlyGenerated(change) {
+		return change.file !== 'plugins/autoloader/prism-autoloader.js' &&
+			change.file !== 'plugins/show-language/prism-show-language.js';
+	}
+	/** @param {CommitChange} change */
+	function notTests(change) {
+		return !/^tests\//.test(change.file);
+	}
+	/** @param {CommitChange} change */
+	function notExamples(change) {
+		return !/^examples\//.test(change.file);
+	}
+	/** @param {CommitChange} change */
+	function notFailures(change) {
+		return !/^known-failures.html$/.test(change.file);
+	}
+	/** @param {CommitChange} change */
+	function notComponentsJSON(change) {
+		return change.file !== 'components.json';
+	}
+
+	/**
+	 * @param {((e: T, index: number) => boolean)[]} filters
+	 * @returns {(e: T, index: number) => boolean}
+	 * @template T
+	 */
+	function and(...filters) {
+		return (e, index) => {
+			for (let i = 0, l = filters.length; i < l; i++) {
+				if (!filters[i](e, index)) {
+					return false;
+				}
+			}
+			return true;
+		};
+	}
+
+	/**
+	 * Some commit message have the format `component changed: actual message`.
+	 * This function can be used to remove this prefix.
+	 *
+	 * @param {string} prefix
+	 * @param {CommitInfo} info
+	 * @returns {{ message: string, hash: string }}
+	 */
+	function removeMessagePrefix(prefix, info) {
+		const source = String.raw`^${prefix.replace(/([^-\w\s])/g, '\\$1').replace(/[-\s]/g, '[-\\s]')}:\s*`;
+		const patter = RegExp(source, 'i');
+		return {
+			message: info.message.replace(patter, ''),
+			hash: info.hash
+		};
+	}
+
+
+	/**
+	 * @type {((info: CommitInfo) => boolean)[]}
+	 */
+	const commitSorters = [
+
+		function rebuild(info) {
+			if (info.changes.length > 0 && info.changes.filter(notGenerated).length === 0) {
+				console.log('Rebuild found: ' + info.message);
+				return true;
+			}
+		},
+
+		function addedComponent(info) {
+			let relevantChanges = info.changes.filter(and(notGenerated, notTests, notExamples, notFailures));
+
+			// `components.json` has to be modified
+			if (relevantChanges.some(c => c.file === 'components.json')) {
+				relevantChanges = relevantChanges.filter(and(notComponentsJSON, notPartlyGenerated));
+
+				// now, only the newly added JS should be left
+				if (relevantChanges.length === 1) {
+					const change = relevantChanges[0];
+					if (change.mode === 'A' && change.file.startsWith('components/prism-')) {
+						const lang = change.file.match(/prism-([\w-]+)\.js$/)[1];
+						const titles = [languages[lang].title];
+						if (languages[lang].aliasTitles) {
+							titles.push(...Object.values(languages[lang].aliasTitles));
+						}
+						addEntry('New components', `__${titles.join('__ & __')}__: ${infoToString(info)}`);
+						return true;
+					}
+				}
+			}
+		},
+
+		function changedComponentOrCore(info) {
+			let relevantChanges = info.changes.filter(and(notGenerated, notTests, notExamples, notFailures));
+
+			// if `components.json` changed, then autoloader and show-language also change
+			if (relevantChanges.some(c => c.file === 'components.json')) {
+				relevantChanges = relevantChanges.filter(and(notComponentsJSON, notPartlyGenerated));
+			}
+
+			if (relevantChanges.length === 1) {
+				const change = relevantChanges[0];
+				if (change.mode === 'M' && change.file.startsWith('components/prism-')) {
+					const lang = change.file.match(/prism-([\w-]+)\.js$/)[1];
+					if (lang === 'core') {
+						addEntry('Other >> Core', removeMessagePrefix('Core', info));
+					} else {
+						const title = languages[lang].title;
+						addEntry('Updated components >> ' + title, removeMessagePrefix(title, info));
+					}
+					return true;
+				}
+			}
+		},
+
+		function changedPlugin(info) {
+			let relevantChanges = info.changes.filter(and(notGenerated, notTests, notExamples, c => !/\.(?:html|css)$/.test(c.file)));
+
+			if (relevantChanges.length > 0 &&
+				relevantChanges.every(c => c.mode === 'M' && /^plugins\/.*\.js$/.test(c.file))) {
+
+				if (relevantChanges.length === 1) {
+					const change = relevantChanges[0];
+					const id = change.file.match(/\/prism-([\w-]+)\.js/)[1];
+					const title = plugins[id].title || plugins[id];
+					addEntry('Updated plugins >> ' + title, removeMessagePrefix(title, info));
+				} else {
+					addEntry('Updated plugins', info);
+				}
+				return true;
+			}
+		},
+
+		function changedTheme(info) {
+			if (info.changes.length > 0 && info.changes.every(c => {
+				return /themes\/.*\.css/.test(c.file) && c.mode === 'M';
+			})) {
+				if (info.changes.length === 1) {
+					const change = info.changes[0];
+					let name = (change.file.match(/prism-(\w+)\.css$/) || [, 'Default'])[1];
+					name = name[0].toUpperCase() + name.substr(1);
+					addEntry('Updated themes >> ' + name, removeMessagePrefix(name, info));
+				} else {
+					addEntry('Updated themes', info);
+				}
+				return true;
+			}
+		},
+
+		function changedInfrastructure(info) {
+			if (info.changes.length > 0 && info.changes.every(c => {
+				if (c.file.startsWith('gulpfile.js')) {
+					return true;
+				}
+				if (/^\.[\w.]+$/.test(c.file)) {
+					return true;
+				}
+				return ['CNAME', 'composer.json', 'package.json', 'package-lock.json'].indexOf(c.file) >= 0;
+			})) {
+				addEntry('Other >> Infrastructure', info);
+				return true;
+			}
+		},
+
+		function changedWebsite(info) {
+			if (info.changes.length > 0 && info.changes.every(c => {
+				if (/[\w-]+\.(?:html|svg)$/.test(c.file)) {
+					return true;
+				}
+				if (/^scripts(?:\/[\w-]+)*\/[\w-]+\.js$/.test(c.file)) {
+					return true;
+				}
+				return ['style.css'].indexOf(c.file) >= 0;
+			})) {
+				addEntry('Other >> Website', info);
+				return true;
+			}
+		},
+
+		function otherChanges(info) {
+			// detect changes of the Github setup
+			// This assumes that .md files are related to GitHub
+			if (info.changes.length > 0 && info.changes.every(c => /\.md$/i.test(c.file))) {
+				addEntry('Other', info);
+				return true;
+			}
+		},
+
+	];
+
+	for (const info of infos) {
+		if (!commitSorters.some(sorter => sorter(info))) {
+			addEntry('TODO:', info);
+		}
+	}
+
+
+	/**
+	 * Stringifies the given commit info.
+	 *
+	 * @param {string | CommitInfo} info
+	 * @returns {string}
+	 */
+	function infoToString(info) {
+		if (typeof info === 'string') {
+			return info;
+		}
+		return `${info.message} [\`${info.hash}\`](https://github.com/PrismJS/prism/commit/${info.hash})`;
+	}
+	function printCategory(category, indentation = '') {
+		for (const subCategory of Object.keys(category).sort(strCompare)) {
+			if (subCategory) {
+				md += `${indentation}* __${subCategory}__\n`;
+				printCategory(category[subCategory], indentation + '    ')
+			} else {
+				for (const info of category['']) {
+					md += `${indentation}* ${infoToString(info)}\n`;
+				}
+			}
+		}
+	}
+
+	let md = '';
+	for (const category of Object.keys(entries)) {
+		md += `\n### ${category}\n\n`;
+		printCategory(entries[category]);
+	}
+	console.log(md);
+}
+
+
+module.exports = {
+	linkify,
+	changes
+};
diff --git a/gulpfile.js/index.js b/gulpfile.js/index.js
new file mode 100644
index 0000000..14e8a19
--- /dev/null
+++ b/gulpfile.js/index.js
@@ -0,0 +1,197 @@
+"use strict";
+
+const { src, dest, series, parallel, watch } = require('gulp');
+
+const rename = require('gulp-rename');
+const uglify = require('gulp-uglify');
+const header = require('gulp-header');
+const concat = require('gulp-concat');
+const replace = require('gulp-replace');
+const pump = require('pump');
+const util = require('util');
+const fs = require('fs');
+
+const paths = require('./paths');
+const { premerge } = require('./premerge');
+const { changes, linkify } = require('./changelog');
+
+
+const componentsPromise = new Promise((resolve, reject) => {
+	fs.readFile(paths.componentsFile, {
+		encoding: 'utf-8'
+	}, (err, data) => {
+		if (!err) {
+			resolve(JSON.parse(data));
+		} else {
+			reject(err);
+		}
+	});
+});
+
+function inlineRegexSource() {
+	return replace(
+		/\/((?:[^\n\r[\\\/]|\\.|\[(?:[^\n\r\\\]]|\\.)*\])*)\/\.source\b/g,
+		(m, source) => {
+			// escape backslashes
+			source = source.replace(/\\/g, '\\\\');
+			// escape single quotes
+			source = source.replace(/'/g, "\\'");
+			// unescape characters like \\n and \\t to \n and \t
+			source = source.replace(/(^|[^\\])\\\\([nrt0])/g, '$1\\$2');
+			// wrap source in single quotes
+			return "'" + source + "'";
+		}
+	);
+}
+
+function minifyJS() {
+	return [
+		inlineRegexSource(),
+		uglify()
+	];
+}
+
+
+function minifyComponents(cb) {
+	pump([src(paths.components), ...minifyJS(), rename({ suffix: '.min' }), dest('components')], cb);
+}
+function minifyPlugins(cb) {
+	pump([src(paths.plugins), ...minifyJS(), rename({ suffix: '.min' }), dest('plugins')], cb);
+}
+function build(cb) {
+	pump([src(paths.main), header(`
+/* **********************************************
+     Begin <%= file.relative %>
+********************************************** */
+
+`), concat('prism.js'), dest('./')], cb);
+}
+
+async function componentsJsonToJs() {
+	const data = await componentsPromise;
+	const js = `var components = ${JSON.stringify(data)};
+if (typeof module !== 'undefined' && module.exports) { module.exports = components; }`;
+	return util.promisify(fs.writeFile)(paths.componentsFileJS, js);
+}
+
+function watchComponentsAndPlugins() {
+	watch(paths.components, parallel(minifyComponents, build));
+	watch(paths.plugins, parallel(minifyPlugins, build));
+}
+
+async function languagePlugins() {
+	const data = await componentsPromise;
+	const languagesMap = {};
+	const dependenciesMap = {};
+	const aliasMap = {};
+
+	/**
+	 * Tries to guess the name of a language given its id.
+	 *
+	 * From `prism-show-language.js`.
+	 *
+	 * @param {string} id The language id.
+	 * @returns {string}
+	 */
+	function guessTitle(id) {
+		if (!id) {
+			return id;
+		}
+		return (id.substring(0, 1).toUpperCase() + id.substring(1)).replace(/s(?=cript)/, 'S');
+	}
+
+	/**
+	 * @param {string} key
+	 * @param {string} title
+	 */
+	function addLanguageTitle(key, title) {
+		if (!languagesMap[key] && guessTitle(key) !== title) {
+			languagesMap[key] = title;
+		}
+	}
+
+	for (const id in data.languages) {
+		if (id !== 'meta') {
+			const language = data.languages[id];
+			const title = language.displayTitle || language.title;
+
+			addLanguageTitle(id, title);
+
+			for (const name in language.aliasTitles) {
+				addLanguageTitle(name, language.aliasTitles[name]);
+			}
+
+			if (language.alias) {
+				if (typeof language.alias === 'string') {
+					aliasMap[language.alias] = id;
+					addLanguageTitle(language.alias, title);
+				} else {
+					language.alias.forEach(function (alias) {
+						aliasMap[alias] = id;
+						addLanguageTitle(alias, title);
+					});
+				}
+			}
+
+			if (language.require) {
+				dependenciesMap[id] = language.require;
+			}
+		}
+	}
+
+	function formattedStringify(json) {
+		return JSON.stringify(json, null, '\t').replace(/\n/g, '\n\t');
+	}
+
+	const jsonLanguagesMap = formattedStringify(languagesMap);
+	const jsonDependenciesMap = formattedStringify(dependenciesMap);
+	const jsonAliasMap = formattedStringify(aliasMap);
+
+	const tasks = [
+		{
+			plugin: paths.showLanguagePlugin,
+			maps: { languages: jsonLanguagesMap }
+		},
+		{
+			plugin: paths.autoloaderPlugin,
+			maps: { aliases: jsonAliasMap, dependencies: jsonDependenciesMap }
+		}
+	];
+
+	// TODO: Use `Promise.allSettled` (https://github.com/tc39/proposal-promise-allSettled)
+	const taskResults = await Promise.all(tasks.map(async task => {
+		try {
+			const value = await new Promise((resolve, reject) => {
+				const stream = src(task.plugin)
+					.pipe(replace(
+						/\/\*(\w+)_placeholder\[\*\/[\s\S]*?\/\*\]\*\//g,
+						(m, mapName) => `/*${mapName}_placeholder[*/${task.maps[mapName]}/*]*/`
+					))
+					.pipe(dest(task.plugin.substring(0, task.plugin.lastIndexOf('/'))));
+
+				stream.on('error', reject);
+				stream.on('end', resolve);
+			});
+			return { status: 'fulfilled', value };
+		} catch (error) {
+			return { status: 'rejected', reason: error };
+		}
+	}));
+
+	const rejectedTasks = taskResults.filter(/** @return {r is {status: 'rejected', reason: any}} */ r => r.status === 'rejected');
+	if (rejectedTasks.length > 0) {
+		throw rejectedTasks.map(r => r.reason);
+	}
+}
+
+const components = minifyComponents;
+const plugins = series(languagePlugins, minifyPlugins);
+
+
+module.exports = {
+	watch: watchComponentsAndPlugins,
+	default: parallel(components, plugins, componentsJsonToJs, build),
+	premerge,
+	linkify,
+	changes
+};
diff --git a/gulpfile.js/paths.js b/gulpfile.js/paths.js
new file mode 100644
index 0000000..1d5b7a3
--- /dev/null
+++ b/gulpfile.js/paths.js
@@ -0,0 +1,19 @@
+"use strict";
+
+module.exports = {
+	componentsFile: 'components.json',
+	componentsFileJS: 'components.js',
+	components: ['components/**/*.js', '!components/index.js', '!components/**/*.min.js'],
+	main: [
+		'components/prism-core.js',
+		'components/prism-markup.js',
+		'components/prism-css.js',
+		'components/prism-clike.js',
+		'components/prism-javascript.js',
+		'plugins/file-highlight/prism-file-highlight.js'
+	],
+	plugins: ['plugins/**/*.js', '!plugins/**/*.min.js'],
+	showLanguagePlugin: 'plugins/show-language/prism-show-language.js',
+	autoloaderPlugin: 'plugins/autoloader/prism-autoloader.js',
+	changelog: 'CHANGELOG.md'
+};
diff --git a/gulpfile.js/premerge.js b/gulpfile.js/premerge.js
new file mode 100644
index 0000000..a78c21b
--- /dev/null
+++ b/gulpfile.js/premerge.js
@@ -0,0 +1,18 @@
+"use strict";
+
+const git = require('simple-git/promise')(__dirname);
+
+
+function gitChanges() {
+	return git.status().then(res => {
+		if (res.files.length > 0) {
+			console.log(res);
+			throw new Error('There are changes in the file system. Did you forget to run gulp?');
+		}
+	});
+}
+
+
+module.exports = {
+	premerge: gitChanges
+};
diff --git a/package-lock.json b/package-lock.json
index bb2538c..2f042d7 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -4252,17 +4252,6 @@
       "integrity": "sha1-2kL0l0DAtC2yypcoVxyxkMmO/qM=",
       "dev": true
     },
-    "shelljs": {
-      "version": "0.8.3",
-      "resolved": "https://registry.npmjs.org/shelljs/-/shelljs-0.8.3.tgz",
-      "integrity": "sha512-fc0BKlAWiLpwZljmOvAOTE/gXawtCoNrP5oaY7KIaQbbyHeQVg01pSEuEGvGh3HEdBU4baCD7wQBwADmM/7f7A==",
-      "dev": true,
-      "requires": {
-        "glob": "^7.0.0",
-        "interpret": "^1.0.0",
-        "rechoir": "^0.6.2"
-      }
-    },
     "signal-exit": {
       "version": "3.0.2",
       "resolved": "https://registry.npmjs.org/signal-exit/-/signal-exit-3.0.2.tgz",
diff --git a/package.json b/package.json
index 1a3fcb6..ddb65e3 100755
--- a/package.json
+++ b/package.json
@@ -37,7 +37,6 @@
     "jsdom": "^13.0.0",
     "mocha": "^6.0.0",
     "pump": "^3.0.0",
-    "shelljs": "^0.8.3",
     "simple-git": "^1.107.0",
     "yargs": "^13.2.2"
   },