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

frontend/node_modules/eslint-plugin-unicorn/rules/prefer-class-fields.js

@@ -0,0 +1,154 @@
+import {isSemicolonToken} from '@eslint-community/eslint-utils';
+import getIndentString from './utils/get-indent-string.js';
+
+const MESSAGE_ID_ERROR = 'prefer-class-fields/error';
+const MESSAGE_ID_SUGGESTION = 'prefer-class-fields/suggestion';
+const messages = {
+	[MESSAGE_ID_ERROR]:
+		'Prefer class field declaration over `this` assignment in constructor for static values.',
+	[MESSAGE_ID_SUGGESTION]:
+		'Encountered same-named class field declaration and `this` assignment in constructor. Replace the class field declaration with the value from `this` assignment.',
+};
+
+/**
+@param {import('eslint').Rule.Node} node
+@param {import('eslint').Rule.RuleContext['sourceCode']} sourceCode
+@param {import('eslint').Rule.RuleFixer} fixer
+*/
+const removeFieldAssignment = (node, sourceCode, fixer) => {
+	const {line} = sourceCode.getLoc(node).start;
+	const nodeText = sourceCode.getText(node);
+	const lineText = sourceCode.lines[line - 1];
+	const isOnlyNodeOnLine = lineText.trim() === nodeText;
+
+	return isOnlyNodeOnLine
+		? fixer.removeRange([
+			sourceCode.getIndexFromLoc({line, column: 0}),
+			sourceCode.getIndexFromLoc({line: line + 1, column: 0}),
+		])
+		: fixer.remove(node);
+};
+
+/**
+@type {import('eslint').Rule.RuleModule['create']}
+*/
+const create = context => {
+	const {sourceCode} = context;
+
+	context.on('ClassBody', classBody => {
+		const constructor = classBody.body.find(node =>
+			node.kind === 'constructor'
+			&& !node.computed
+			&& !node.static
+			&& node.type === 'MethodDefinition'
+			&& node.value.type === 'FunctionExpression');
+
+		if (!constructor) {
+			return;
+		}
+
+		const node = constructor.value.body.body.find(node => node.type !== 'EmptyStatement');
+
+		if (!(
+			node?.type === 'ExpressionStatement'
+			&& node.expression.type === 'AssignmentExpression'
+			&& node.expression.operator === '='
+			&& node.expression.left.type === 'MemberExpression'
+			&& node.expression.left.object.type === 'ThisExpression'
+			&& !node.expression.left.computed
+			&& ['Identifier', 'PrivateIdentifier'].includes(node.expression.left.property.type)
+			&& node.expression.right.type === 'Literal'
+		)) {
+			return;
+		}
+
+		const propertyName = node.expression.left.property.name;
+		const propertyValue = node.expression.right.raw;
+		const propertyType = node.expression.left.property.type;
+		const existingProperty = classBody.body.find(node =>
+			node.type === 'PropertyDefinition'
+			&& !node.computed
+			&& !node.static
+			&& node.key.type === propertyType
+			&& node.key.name === propertyName);
+
+		const problem = {
+			node,
+			messageId: MESSAGE_ID_ERROR,
+		};
+
+		/**
+			@param {import('eslint').Rule.RuleFixer} fixer
+			*/
+		function * fix(fixer) {
+			yield removeFieldAssignment(node, sourceCode, fixer);
+
+			if (existingProperty) {
+				if (existingProperty.value) {
+					yield fixer.replaceText(existingProperty.value, propertyValue);
+					return;
+				}
+
+				const text = ` = ${propertyValue}`;
+				const lastToken = sourceCode.getLastToken(existingProperty);
+				if (isSemicolonToken(lastToken)) {
+					yield fixer.insertTextBefore(lastToken, text);
+					return;
+				}
+
+				yield fixer.insertTextAfter(existingProperty, `${text};`);
+				return;
+			}
+
+			const closingBrace = sourceCode.getLastToken(classBody);
+			const indent = getIndentString(constructor, context);
+
+			let text = `${indent}${propertyName} = ${propertyValue};\n`;
+
+			const characterBefore = sourceCode.getText()[sourceCode.getRange(closingBrace)[0] - 1];
+			if (characterBefore !== '\n') {
+				text = `\n${text}`;
+			}
+
+			const lastProperty = classBody.body.at(-1);
+			if (
+				lastProperty.type === 'PropertyDefinition'
+				&& sourceCode.getLastToken(lastProperty).value !== ';'
+			) {
+				text = `;${text}`;
+			}
+
+			yield fixer.insertTextBefore(closingBrace, text);
+		}
+
+		if (existingProperty?.value) {
+			problem.suggest = [
+				{
+					messageId: MESSAGE_ID_SUGGESTION,
+					fix,
+				},
+			];
+			return problem;
+		}
+
+		problem.fix = fix;
+		return problem;
+	});
+};
+
+/** @type {import('eslint').Rule.RuleModule} */
+const config = {
+	create,
+	meta: {
+		type: 'suggestion',
+		docs: {
+			description: 'Prefer class field declarations over `this` assignments in constructors.',
+			recommended: 'unopinionated',
+		},
+		fixable: 'code',
+		hasSuggestions: true,
+		messages,
+	},
+};
+
+export default config;