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

frontend/node_modules/eslint-plugin-unicorn/rules/no-useless-length-check.js

@@ -0,0 +1,145 @@
+import {isMethodCall, isMemberExpression} from './ast/index.js';
+import {getParenthesizedRange, isSameReference, isLogicalExpression} from './utils/index.js';
+
+const messages = {
+	'non-zero': 'The non-empty check is useless as `Array#some()` returns `false` for an empty array.',
+	zero: 'The empty check is useless as `Array#every()` returns `true` for an empty array.',
+};
+
+// We assume the user already follows `unicorn/explicit-length-check`. These are allowed in that rule.
+const isLengthCompareZero = node =>
+	node.type === 'BinaryExpression'
+	&& node.right.type === 'Literal'
+	&& node.right.raw === '0'
+	&& isMemberExpression(node.left, {property: 'length', optional: false})
+	&& isLogicalExpression(node.parent);
+
+function flatLogicalExpression(node) {
+	return [node.left, node.right].flatMap(child =>
+		child.type === 'LogicalExpression' && child.operator === node.operator
+			? flatLogicalExpression(child)
+			: [child]);
+}
+
+/** @param {import('eslint').Rule.RuleContext} context */
+const create = context => {
+	const logicalExpressions = [];
+	const zeroLengthChecks = new Set();
+	const nonZeroLengthChecks = new Set();
+	const arraySomeCalls = new Set();
+	const arrayEveryCalls = new Set();
+
+	function isUselessLengthCheckNode({node, operator, siblings}) {
+		return (
+			(
+				operator === '||'
+				&& zeroLengthChecks.has(node)
+				&& siblings.some(condition =>
+					arrayEveryCalls.has(condition)
+					&& isSameReference(node.left.object, condition.callee.object))
+			)
+			|| (
+				operator === '&&'
+				&& nonZeroLengthChecks.has(node)
+				&& siblings.some(condition =>
+					arraySomeCalls.has(condition)
+					&& isSameReference(node.left.object, condition.callee.object))
+			)
+		);
+	}
+
+	function getUselessLengthCheckNode(logicalExpression) {
+		const {operator} = logicalExpression;
+		return flatLogicalExpression(logicalExpression)
+			.filter((node, index, conditions) => isUselessLengthCheckNode({
+				node,
+				operator,
+				siblings: [
+					conditions[index - 1],
+					conditions[index + 1],
+				].filter(Boolean),
+			}));
+	}
+
+	context.on('BinaryExpression', node => {
+		if (isLengthCompareZero(node)) {
+			const {operator} = node;
+			if (operator === '===') {
+				zeroLengthChecks.add(node);
+			} else if (operator === '>' || operator === '!==') {
+				nonZeroLengthChecks.add(node);
+			}
+		}
+	});
+
+	context.on('CallExpression', node => {
+		if (
+			isMethodCall(node, {
+				optionalCall: false,
+				optionalMember: false,
+				computed: false,
+			})
+			&& node.callee.property.type === 'Identifier'
+		) {
+			if (node.callee.property.name === 'some') {
+				arraySomeCalls.add(node);
+			} else if (node.callee.property.name === 'every') {
+				arrayEveryCalls.add(node);
+			}
+		}
+	});
+
+	context.on('LogicalExpression', node => {
+		if (isLogicalExpression(node)) {
+			logicalExpressions.push(node);
+		}
+	});
+
+	context.on('Program:exit', function * () {
+		const nodes = new Set(logicalExpressions.flatMap(logicalExpression =>
+			getUselessLengthCheckNode(logicalExpression)));
+		const {sourceCode} = context;
+
+		for (const node of nodes) {
+			yield {
+				loc: {
+					start: sourceCode.getLoc(node.left.property).start,
+					end: sourceCode.getLoc(node).end,
+				},
+				messageId: zeroLengthChecks.has(node) ? 'zero' : 'non-zero',
+				/** @param {import('eslint').Rule.RuleFixer} fixer */
+				fix(fixer) {
+					const {left, right} = node.parent;
+					const leftRange = getParenthesizedRange(left, context);
+					const rightRange = getParenthesizedRange(right, context);
+					const range = [];
+					if (left === node) {
+						range[0] = leftRange[0];
+						range[1] = rightRange[0];
+					} else {
+						range[0] = leftRange[1];
+						range[1] = rightRange[1];
+					}
+
+					return fixer.removeRange(range);
+				},
+			};
+		}
+	});
+};
+
+/** @type {import('eslint').Rule.RuleModule} */
+const config = {
+	create,
+	meta: {
+		type: 'suggestion',
+		docs: {
+			description: 'Disallow useless array length check.',
+			recommended: 'unopinionated',
+		},
+		fixable: 'code',
+		messages,
+	},
+};
+
+export default config;