--- /dev/null
+"use strict";
+
+const _ = require("lodash");
+const atRuleParamIndex = require("../../utils/atRuleParamIndex");
+const isCustomMediaQuery = require("../../utils/isCustomMediaQuery");
+const isRangeContextMediaFeature = require("../../utils/isRangeContextMediaFeature");
+const isStandardSyntaxMediaFeatureName = require("../../utils/isStandardSyntaxMediaFeatureName");
+const keywordSets = require("../../reference/keywordSets");
+const mediaParser = require("postcss-media-query-parser").default;
+const optionsMatches = require("../../utils/optionsMatches");
+const postcss = require("postcss");
+const report = require("../../utils/report");
+const ruleMessages = require("../../utils/ruleMessages");
+const validateOptions = require("../../utils/validateOptions");
+
+const ruleName = "media-feature-name-no-unknown";
+
+const messages = ruleMessages(ruleName, {
+ rejected: mediaFeatureName =>
+ `Unexpected unknown media feature name "${mediaFeatureName}"`
+});
+
+const rule = function(actual, options) {
+ return (root, result) => {
+ const validOptions = validateOptions(
+ result,
+ ruleName,
+ { actual },
+ {
+ actual: options,
+ possible: {
+ ignoreMediaFeatureNames: [_.isString]
+ },
+ optional: true
+ }
+ );
+
+ if (!validOptions) {
+ return;
+ }
+
+ root.walkAtRules(/^media$/i, atRule => {
+ mediaParser(atRule.params).walk(/^media-feature$/i, mediaFeatureNode => {
+ const parent = mediaFeatureNode.parent,
+ sourceIndex = mediaFeatureNode.sourceIndex,
+ value = mediaFeatureNode.value;
+
+ if (
+ isRangeContextMediaFeature(parent.value) ||
+ !isStandardSyntaxMediaFeatureName(value) ||
+ isCustomMediaQuery(value)
+ ) {
+ return;
+ }
+
+ if (optionsMatches(options, "ignoreMediaFeatureNames", value)) {
+ return;
+ }
+
+ if (
+ postcss.vendor.prefix(value) ||
+ keywordSets.mediaFeatureNames.has(value.toLowerCase())
+ ) {
+ return;
+ }
+
+ report({
+ index: atRuleParamIndex(atRule) + sourceIndex,
+ message: messages.rejected(value),
+ node: atRule,
+ ruleName,
+ result
+ });
+ });
+ });
+ };
+};
+
+rule.ruleName = ruleName;
+rule.messages = messages;
+module.exports = rule;