stylelint/lib/rules/selector-type-case/index.mjs

A mighty CSS linter that helps you avoid errors and enforce conventions.

import { isRegExp, isString } from '../../utils/validateTypes.mjs';
import getRuleSelector from '../../utils/getRuleSelector.mjs';
import isKeyframeSelector from '../../utils/isKeyframeSelector.mjs';
import isStandardSyntaxRule from '../../utils/isStandardSyntaxRule.mjs';
import isStandardSyntaxTypeSelector from '../../utils/isStandardSyntaxTypeSelector.mjs';
import { mixedCaseSvgTypeSelectors } from '../../reference/selectors.mjs';
import optionsMatches from '../../utils/optionsMatches.mjs';
import parseSelector from '../../utils/parseSelector.mjs';
import report from '../../utils/report.mjs';
import ruleMessages from '../../utils/ruleMessages.mjs';
import validateOptions from '../../utils/validateOptions.mjs';

const ruleName = 'selector-type-case';

const messages = ruleMessages(ruleName, {
	expected: (actual, expected) => `Expected "${actual}" to be "${expected}"`,
});

const meta = {
	url: 'https://stylelint.io/user-guide/rules/selector-type-case',
	fixable: true,
};

const STARTS_A_TAG_NAME_REGEX = /(?:[^.#[:a-z-]|^)[a-z]/i;
const ANY_UPPER_CASE_REGEX = /[A-Z]/;
const ANY_LOWER_CASE_REGEX = /[a-z]/;

/** @type {import('stylelint').CoreRules[ruleName]} */
const rule = (primary, secondaryOptions) => {
	return (root, result) => {
		const validOptions = validateOptions(
			result,
			ruleName,
			{
				actual: primary,
				possible: ['lower', 'upper'],
			},
			{
				actual: secondaryOptions,
				possible: {
					ignoreTypes: [isString, isRegExp],
				},
				optional: true,
			},
		);

		if (!validOptions) {
			return;
		}

		root.walkRules((ruleNode) => {
			const selector = ruleNode.selector;

			if (!STARTS_A_TAG_NAME_REGEX.test(selector)) return;

			if (primary === 'lower' && !ANY_UPPER_CASE_REGEX.test(selector)) return;

			if (primary === 'upper' && !ANY_LOWER_CASE_REGEX.test(selector)) return;

			if (!isStandardSyntaxRule(ruleNode)) return;

			if (ruleNode.selectors.some(isKeyframeSelector)) return;

			const selectorRoot = parseSelector(getRuleSelector(ruleNode), result, ruleNode);

			if (!selectorRoot) return;

			selectorRoot.walkTags((tag) => {
				if (!isStandardSyntaxTypeSelector(tag)) {
					return;
				}

				if (mixedCaseSvgTypeSelectors.has(tag.value)) {
					return;
				}

				if (optionsMatches(secondaryOptions, 'ignoreTypes', tag.value)) {
					return;
				}

				const sourceIndex = tag.sourceIndex;
				const value = tag.value;

				const expectedValue = primary === 'lower' ? value.toLowerCase() : value.toUpperCase();

				if (value === expectedValue) {
					return;
				}

				const index = sourceIndex;
				const endIndex = sourceIndex + value.length;
				const fix = () => {
					tag.value = expectedValue;
					ruleNode.selector = selectorRoot.toString();
				};

				report({
					message: messages.expected,
					messageArgs: [value, expectedValue],
					node: ruleNode,
					index,
					endIndex,
					ruleName,
					result,
					fix: {
						apply: fix,
						node: ruleNode,
					},
				});
			});
		});
	};
};

rule.ruleName = ruleName;
rule.messages = messages;
rule.meta = meta;
export default rule;