--- /dev/null
+"use strict";
+
+const report = require("../../utils/report");
+const ruleMessages = require("../../utils/ruleMessages");
+const validateOptions = require("../../utils/validateOptions");
+
+const ruleName = "at-rule-name-case";
+
+const messages = ruleMessages(ruleName, {
+ expected: (actual, expected) => `Expected "${actual}" to be "${expected}"`
+});
+
+const rule = function(expectation, options, context) {
+ return (root, result) => {
+ const validOptions = validateOptions(result, ruleName, {
+ actual: expectation,
+ possible: ["lower", "upper"]
+ });
+ if (!validOptions) {
+ return;
+ }
+
+ root.walkAtRules(atRule => {
+ const name = atRule.name;
+
+ const expectedName =
+ expectation === "lower" ? name.toLowerCase() : name.toUpperCase();
+
+ if (name === expectedName) {
+ return;
+ }
+
+ if (context.fix) {
+ atRule.name = expectedName;
+ return;
+ }
+
+ report({
+ message: messages.expected(name, expectedName),
+ node: atRule,
+ ruleName,
+ result
+ });
+ });
+ };
+};
+
+rule.ruleName = ruleName;
+rule.messages = messages;
+module.exports = rule;