Use text-diff

commands/games-sp/typing-test.js

@@ -1,8 +1,9 @@
 const Command = require('../../structures/Command');
 const { createCanvas, registerFont } = require('canvas');
 const { stripIndents } = require('common-tags');
+const Diff = require('text-diff');
 const path = require('path');
-const { textDiff, fetchHSUserDisplay } = require('../../util/Util');
+const { fetchHSUserDisplay } = require('../../util/Util');
 const words = require('../../assets/json/word-list');
 registerFont(path.join(__dirname, '..', '..', 'assets', 'fonts', 'Noto-Regular.ttf'), { family: 'Noto' });
 
@@ -39,9 +40,16 @@ module.exports = class TypingTestCommand extends Command {
 		}
 		if (!msgs.size) return msg.reply('Sorry! You lose!');
 		if (msgs.first().content.toLowerCase() !== sentence) {
+			const diff = new Diff();
+			const textDiff = diff.main(msgs.first().content.toLowerCase(), sentence);
+			const formatted = diff.cleanupSemantic(textDiff).map(change => {
+				if (change[0] === 1) return `**${change[1]}**`;
+				if (change[0] === 0) return change[1];
+				return '';
+			}).join('');
 			return msg.reply(stripIndents`
 				Sorry! You made a typo, so you lose!
-				${textDiff(msgs.first().content.toLowerCase(), sentence)}
+				${formatted}
 			`);
 		}
 		const wpm = (sentence.length / 5) / ((newScore / 1000) / 60);

package.json

@@ -70,6 +70,7 @@
 		"sherlockjs": "^1.4.0",
 		"stackblur-canvas": "^2.4.0",
 		"tesseract.js": "^2.1.4",
+		"text-diff": "^1.0.1",
 		"tictactoe-minimax-ai": "^1.2.1",
 		"valid-url": "^1.0.9",
 		"winston": "^3.3.3"

util/Util.js

@@ -181,20 +181,6 @@ module.exports = class Util {
 		return ((r << 16) | (g << 8) | b).toString(16);
 	}
 
-	static textDiff(oldText, newText) {
-		let changed = [];
-		return oldText.split('').map((char, i) => {
-			if (char === newText.charAt(i)) {
-				const chars = changed.length ? `**${changed.join('')}**${char}` : char;
-				if (changed.length) changed = [];
-				const extraText = newText.slice(oldText.length);
-				return i === oldText.length - 1 ? `${chars}${extraText.length ? `**${extraText}**` : ''}` : chars;
-			}
-			changed.push(newText.charAt(i));
-			return i === oldText.length - 1 ? `**${changed.join('')}${newText.slice(oldText.length)}**` : '';
-		}).join('');
-	}
-
 	static magikToBuffer(magik) {
 		return new Promise((res, rej) => {
 			magik.toBuffer((err, buffer) => {