routie dev init since i didn't adhere to any proper guidance up until now

frontend/node_modules/eslint-plugin-unicorn/rules/prefer-code-point.js

@@ -0,0 +1,57 @@
+import {isMemberExpression, isMethodCall} from './ast/index.js';
+
+const messages = {
+	'error/charCodeAt': 'Prefer `String#codePointAt()` over `String#charCodeAt()`.',
+	'error/fromCharCode': 'Prefer `String.fromCodePoint()` over `String.fromCharCode()`.',
+	'suggestion/codePointAt': 'Use `String#codePointAt()`.',
+	'suggestion/fromCodePoint': 'Use `String.fromCodePoint()`.',
+};
+
+const getProblem = (node, replacement) => ({
+	node,
+	messageId: `error/${node.name}`,
+	suggest: [
+		{
+			messageId: `suggestion/${replacement}`,
+			fix: fixer => fixer.replaceText(node, replacement),
+		},
+	],
+});
+
+/** @param {import('eslint').Rule.RuleContext} context */
+const create = context => {
+	context.on('CallExpression', node => {
+		if (isMethodCall(node, {
+			method: 'charCodeAt',
+			optionalCall: false,
+		})) {
+			return getProblem(node.callee.property, 'codePointAt');
+		}
+	});
+
+	context.on('MemberExpression', node => {
+		if (isMemberExpression(node, {
+			object: 'String',
+			property: 'fromCharCode',
+			optional: false,
+		})) {
+			return getProblem(node.property, 'fromCodePoint');
+		}
+	});
+};
+
+/** @type {import('eslint').Rule.RuleModule} */
+const config = {
+	create,
+	meta: {
+		type: 'suggestion',
+		docs: {
+			description: 'Prefer `String#codePointAt(…)` over `String#charCodeAt(…)` and `String.fromCodePoint(…)` over `String.fromCharCode(…)`.',
+			recommended: 'unopinionated',
+		},
+		hasSuggestions: true,
+		messages,
+	},
+};
+
+export default config;