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

2026-04-29 22:27:29 -06:00
commit e1dabb71e2
15301 changed files with 3562618 additions and 0 deletions
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+import toLocation from './utils/to-location.js';
+import {isMethodCall, isNegativeOne, isNumericLiteral} from './ast/index.js';
+
+const MESSAGE_ID = 'consistent-existence-index-check';
+const messages = {
+	[MESSAGE_ID]: 'Prefer `{{replacementOperator}} {{replacementValue}}` over `{{originalOperator}} {{originalValue}}` to check {{existenceOrNonExistence}}.',
+};
+
+const isZero = node => isNumericLiteral(node) && node.value === 0;
+
+/**
+@param {parent: import('estree').BinaryExpression} binaryExpression
+@returns {{
+	replacementOperator: string,
+	replacementValue: string,
+	originalOperator: string,
+	originalValue: string,
+} | undefined}
+*/
+function getReplacement(binaryExpression) {
+	const {operator, right} = binaryExpression;
+
+	if (operator === '<' && isZero(right)) {
+		return {
+			replacementOperator: '===',
+			replacementValue: '-1',
+			originalOperator: operator,
+			originalValue: '0',
+		};
+	}
+
+	if (operator === '>' && isNegativeOne(right)) {
+		return {
+			replacementOperator: '!==',
+			replacementValue: '-1',
+			originalOperator: operator,
+			originalValue: '-1',
+		};
+	}
+
+	if (operator === '>=' && isZero(right)) {
+		return {
+			replacementOperator: '!==',
+			replacementValue: '-1',
+			originalOperator: operator,
+			originalValue: '0',
+		};
+	}
+}
+
+/** @param {import('eslint').Rule.RuleContext} context */
+const create = context => {
+	context.on('VariableDeclarator', /** @param {import('estree').VariableDeclarator} variableDeclarator */ function * (variableDeclarator) {
+		if (!(
+			variableDeclarator.parent.type === 'VariableDeclaration'
+			&& variableDeclarator.parent.kind === 'const'
+			&& variableDeclarator.id.type === 'Identifier'
+			&& isMethodCall(variableDeclarator.init, {methods: ['indexOf', 'lastIndexOf', 'findIndex', 'findLastIndex']})
+		)) {
+			return;
+		}
+
+		const variableIdentifier = variableDeclarator.id;
+		const variables = context.sourceCode.getDeclaredVariables(variableDeclarator);
+		const [variable] = variables;
+
+		// Just for safety
+		if (
+			variables.length !== 1
+			|| variable.identifiers.length !== 1
+			|| variable.identifiers[0] !== variableIdentifier
+		) {
+			return;
+		}
+
+		for (const {identifier} of variable.references) {
+			/** @type {{parent: import('estree').BinaryExpression}} */
+			const binaryExpression = identifier.parent;
+
+			if (binaryExpression.type !== 'BinaryExpression' || binaryExpression.left !== identifier) {
+				continue;
+			}
+
+			const replacement = getReplacement(binaryExpression);
+
+			if (!replacement) {
+				return;
+			}
+
+			const {left, operator, right} = binaryExpression;
+			const {sourceCode} = context;
+
+			const operatorToken = sourceCode.getTokenAfter(
+				left,
+				token => token.type === 'Punctuator' && token.value === operator,
+			);
+
+			const [start] = sourceCode.getRange(operatorToken);
+			const [, end] = sourceCode.getRange(right);
+
+			yield {
+				node: binaryExpression,
+				loc: toLocation([start, end], context),
+				messageId: MESSAGE_ID,
+				data: {
+					...replacement,
+					existenceOrNonExistence: `${replacement.replacementOperator === '===' ? 'non-' : ''}existence`,
+				},
+				* fix(fixer) {
+					yield fixer.replaceText(operatorToken, replacement.replacementOperator);
+
+					if (replacement.replacementValue !== replacement.originalValue) {
+						yield fixer.replaceText(right, replacement.replacementValue);
+					}
+				},
+			};
+		}
+	});
+};
+
+/** @type {import('eslint').Rule.RuleModule} */
+const config = {
+	create,
+	meta: {
+		type: 'problem',
+		docs: {
+			description:
+				'Enforce consistent style for element existence checks with `indexOf()`, `lastIndexOf()`, `findIndex()`, and `findLastIndex()`.',
+			recommended: 'unopinionated',
+		},
+		fixable: 'code',
+		messages,
+	},
+};
+
+export default config;