Build clean text message only once

client/js/libs/handlebars/ircmessageparser/merge.js

@@ -24,10 +24,7 @@ function sortParts(a, b) {
 // different styles, the first resulting part will contain fragments "fo" and
 // "o", and the second resulting part will contain "b" and "ar". "o" and "b"
 // fragments will contain duplicate styling attributes.
-function merge(textParts, styleFragments) {
-	// Re-build the overall text (without control codes) from the style fragments
-	const cleanText = styleFragments.reduce((acc, frag) => acc + frag.text, "");
-
+function merge(textParts, styleFragments, cleanText) {
 	// Every section of the original text that has not been captured in a "part"
 	// is filled with "text" parts, dummy objects with start/end but no extra
 	// metadata.

client/js/libs/handlebars/parse.js

@@ -91,7 +91,7 @@ module.exports = function parse(text, users) {
 
 	// Merge the styling information with the channels / URLs / nicks / text objects and
 	// generate HTML strings with the resulting fragments
-	return merge(parts, styleFragments).map((textPart) => {
+	return merge(parts, styleFragments, cleanText).map((textPart) => {
 		// Create HTML strings with styling information
 		const fragments = textPart.fragments.map(createFragment).join("");
 

test/client/js/libs/handlebars/ircmessageparser/merge.js

@@ -56,7 +56,7 @@ describe("merge", () => {
 			}],
 		}];
 
-		const actual = merge(textParts, styleFragments);
+		const actual = merge(textParts, styleFragments, styleFragments.map((fragment) => fragment.text).join(""));
 
 		expect(actual).to.deep.equal(expected);
 	});