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 {isMethodCall, isCallExpression, isNullLiteral} from './ast/index.js';
+
+const ERROR_MESSAGE_ID = 'error';
+const SUGGESTION_REPLACE_MESSAGE_ID = 'replace';
+const SUGGESTION_REMOVE_MESSAGE_ID = 'remove';
+const messages = {
+	[ERROR_MESSAGE_ID]: 'Use `undefined` instead of `null`.',
+	[SUGGESTION_REPLACE_MESSAGE_ID]: 'Replace `null` with `undefined`.',
+	[SUGGESTION_REMOVE_MESSAGE_ID]: 'Remove `null`.',
+};
+
+const isLooseEqual = node => node.type === 'BinaryExpression' && ['==', '!='].includes(node.operator);
+const isStrictEqual = node => node.type === 'BinaryExpression' && ['===', '!=='].includes(node.operator);
+
+/** @param {import('eslint').Rule.RuleContext} context */
+const create = context => {
+	const {checkStrictEquality} = context.options[0];
+
+	context.on('Literal', node => {
+		if (
+			!isNullLiteral(node)
+			|| (!checkStrictEquality && isStrictEqual(node.parent))
+			// `Object.create(null)`, `Object.create(null, foo)`
+			|| (
+				isMethodCall(node.parent, {
+					object: 'Object',
+					method: 'create',
+					minimumArguments: 1,
+					maximumArguments: 2,
+					optionalCall: false,
+					optionalMember: false,
+				})
+				&& node.parent.arguments[0] === node
+			)
+			// `useRef(null)`
+			|| (
+				isCallExpression(node.parent, {
+					name: 'useRef',
+					argumentsLength: 1,
+					optionalCall: false,
+					optionalMember: false,
+				})
+				&& node.parent.arguments[0] === node
+			)
+			// `React.useRef(null)`
+			|| (
+				isMethodCall(node.parent, {
+					object: 'React',
+					method: 'useRef',
+					argumentsLength: 1,
+					optionalCall: false,
+					optionalMember: false,
+				})
+				&& node.parent.arguments[0] === node
+			)
+			// `foo.insertBefore(bar, null)`
+			|| (
+				isMethodCall(node.parent, {
+					method: 'insertBefore',
+					argumentsLength: 2,
+					optionalCall: false,
+				})
+				&& node.parent.arguments[1] === node
+			)
+		) {
+			return;
+		}
+
+		const {parent} = node;
+
+		const problem = {
+			node,
+			messageId: ERROR_MESSAGE_ID,
+		};
+
+		const useUndefinedFix = fixer => fixer.replaceText(node, 'undefined');
+
+		if (isLooseEqual(parent)) {
+			problem.fix = useUndefinedFix;
+			return problem;
+		}
+
+		const useUndefinedSuggestion = {
+			messageId: SUGGESTION_REPLACE_MESSAGE_ID,
+			fix: useUndefinedFix,
+		};
+
+		if (parent.type === 'ReturnStatement' && parent.argument === node) {
+			problem.suggest = [
+				{
+					messageId: SUGGESTION_REMOVE_MESSAGE_ID,
+					fix: fixer => fixer.remove(node),
+				},
+				useUndefinedSuggestion,
+			];
+			return problem;
+		}
+
+		if (parent.type === 'VariableDeclarator' && parent.init === node && parent.parent.kind !== 'const') {
+			const {sourceCode} = context;
+			const [, start] = sourceCode.getRange(parent.id);
+			const [, end] = sourceCode.getRange(node);
+			problem.suggest = [
+				{
+					messageId: SUGGESTION_REMOVE_MESSAGE_ID,
+					fix: fixer => fixer.removeRange([start, end]),
+				},
+				useUndefinedSuggestion,
+			];
+			return problem;
+		}
+
+		problem.suggest = [useUndefinedSuggestion];
+		return problem;
+	});
+};
+
+const schema = [
+	{
+		type: 'object',
+		additionalProperties: false,
+		properties: {
+			checkStrictEquality: {
+				type: 'boolean',
+				description: 'Whether to check strict equality comparisons against `null`.',
+			},
+		},
+	},
+];
+
+/** @type {import('eslint').Rule.RuleModule} */
+const config = {
+	create,
+	meta: {
+		type: 'suggestion',
+		docs: {
+			description: 'Disallow the use of the `null` literal.',
+			recommended: true,
+		},
+		fixable: 'code',
+		hasSuggestions: true,
+		schema,
+		defaultOptions: [{checkStrictEquality: false}],
+		messages,
+	},
+};
+
+export default config;