RegExp improvements suggested by LGTM (#17500)

app/autotranslate/server/autotranslate.js

@@ -156,7 +156,7 @@ export class AutoTranslate {
 		message = Markdown.parseMessageNotEscaped(message);
 
 		// Some parsers (e. g. Marked) wrap the complete message in a <p> - this is unnecessary and should be ignored with respect to translations
-		const regexWrappedParagraph = new RegExp('^\s*<p>|<\/p>\s*$', 'gm');
+		const regexWrappedParagraph = new RegExp('^\\s*<p>|</p>\\s*$', 'gm');
 		message.msg = message.msg.replace(regexWrappedParagraph, '');
 
 		for (const tokenIndex in message.tokens) {

app/file-upload/server/lib/FileUpload.js

@@ -318,7 +318,7 @@ export const FileUpload = {
 		// This file type can be pretty much anything, so it's better if we don't mess with the file extension
 		if (file.type !== 'application/octet-stream') {
 			const ext = mime.extension(file.type);
-			if (ext && new RegExp(`\.${ ext }$`, 'i').test(file.name) === false) {
+			if (ext && new RegExp(`\\.${ ext }$`, 'i').test(file.name) === false) {
 				file.name = `${ file.name }.${ ext }`;
 			}
 		}

app/file-upload/server/lib/proxy.js

@@ -30,7 +30,7 @@ WebApp.connectHandlers.stack.unshift({
 		const path = parsedUrl.pathname.substr(UploadFS.config.storesPath.length + 1);
 
 		// Get store
-		const regExp = new RegExp('^\/([^\/\?]+)\/([^\/\?]+)$');
+		const regExp = new RegExp('^/([^/?]+)/([^/?]+)$');
 		const match = regExp.exec(path);
 
 		// Request is not valid

app/highlight-words/client/helper.js

@@ -16,7 +16,7 @@ const highlightTemplate = '$1<span class="highlight-text">$2</span>$3';
 
 export const getRegexHighlight = (highlight) => new RegExp(`(^|\\b|[\\s\\n\\r\\t.,،'\\\"\\+!?:-])(${ s.escapeRegExp(highlight) })($|\\b|[\\s\\n\\r\\t.,،'\\\"\\+!?:-])(?![^<]*>|[^<>]*<\\/)`, 'gmi');
 
-export const getRegexHighlightUrl = (highlight) => new RegExp(`https?:\/\/(www\.)?[-a-zA-Z0-9@:%._\\+~#=]{2,256}\.[a-z]{2,6}\\b([-a-zA-Z0-9@:%_\\+.~#?&//=]*)(${ s.escapeRegExp(highlight) })\\b([-a-zA-Z0-9@:%_\\+.~#?&//=]*)`, 'gmi');
+export const getRegexHighlightUrl = (highlight) => new RegExp(`https?:\/\/(www\\.)?[-a-zA-Z0-9@:%._\\+~#=]{2,256}\\.[a-z]{2,6}\\b([-a-zA-Z0-9@:%_\\+.~#?&//=]*)(${ s.escapeRegExp(highlight) })\\b([-a-zA-Z0-9@:%_\\+.~#?&//=]*)`, 'gmi');
 
 export const highlightWords = (msg, highlights) => highlights.reduce((msg, { highlight, regex, urlRegex }) => {
 	const urlMatches = checkHighlightedWordsInUrls(msg, urlRegex);

app/oembed/server/providers.js

@@ -39,32 +39,32 @@ class Providers {
 const providers = new Providers();
 
 providers.registerProvider({
-	urls: [new RegExp('https?://soundcloud.com/\\S+')],
+	urls: [new RegExp('https?://soundcloud\\.com/\\S+')],
 	endPoint: 'https://soundcloud.com/oembed?format=json&maxheight=150',
 });
 
 providers.registerProvider({
-	urls: [new RegExp('https?://vimeo.com/[^/]+'), new RegExp('https?://vimeo.com/channels/[^/]+/[^/]+'), new RegExp('https://vimeo.com/groups/[^/]+/videos/[^/]+')],
+	urls: [new RegExp('https?://vimeo\\.com/[^/]+'), new RegExp('https?://vimeo\\.com/channels/[^/]+/[^/]+'), new RegExp('https://vimeo\\.com/groups/[^/]+/videos/[^/]+')],
 	endPoint: 'https://vimeo.com/api/oembed.json?maxheight=200',
 });
 
 providers.registerProvider({
-	urls: [new RegExp('https?://www.youtube.com/\\S+'), new RegExp('https?://youtu.be/\\S+')],
+	urls: [new RegExp('https?://www\\.youtube\\.com/\\S+'), new RegExp('https?://youtu\\.be/\\S+')],
 	endPoint: 'https://www.youtube.com/oembed?maxheight=200',
 });
 
 providers.registerProvider({
-	urls: [new RegExp('https?://www.rdio.com/\\S+'), new RegExp('https?://rd.io/\\S+')],
+	urls: [new RegExp('https?://www\\.rdio\\.com/\\S+'), new RegExp('https?://rd\\.io/\\S+')],
 	endPoint: 'https://www.rdio.com/api/oembed/?format=json&maxheight=150',
 });
 
 providers.registerProvider({
-	urls: [new RegExp('https?://www.slideshare.net/[^/]+/[^/]+')],
+	urls: [new RegExp('https?://www\\.slideshare\\.net/[^/]+/[^/]+')],
 	endPoint: 'https://www.slideshare.net/api/oembed/2?format=json&maxheight=200',
 });
 
 providers.registerProvider({
-	urls: [new RegExp('https?://www.dailymotion.com/video/\\S+')],
+	urls: [new RegExp('https?://www\\.dailymotion\\.com/video/\\S+')],
 	endPoint: 'https://www.dailymotion.com/services/oembed?maxheight=200',
 });
 

app/ui-message/client/messageBox/messageBoxAutogrow.js

@@ -34,9 +34,9 @@ export const setupAutogrow = (textarea: HTMLTextAreaElement, shadow: HTMLDivElem
 			return true;
 		}
 
-		const shadowText = text.replace(/</g, '&lt;')
+		const shadowText = text.replace(/&/g, '&amp;')
+			.replace(/</g, '&lt;')
 			.replace(/>/g, '&gt;')
-			.replace(/&/g, '&amp;')
 			.replace(/\n$/, '<br/>&nbsp;')
 			.replace(/\n/g, '<br/>')
 			.replace(/ {2,}/g, replaceWhitespaces);