--- /dev/null
+"use strict";
+
+const _ = require("lodash");
+const declarationValueIndex = require("../../utils/declarationValueIndex");
+const findFontFamily = require("../../utils/findFontFamily");
+const keywordSets = require("../../reference/keywordSets");
+const optionsMatches = require("../../utils/optionsMatches");
+const report = require("../../utils/report");
+const ruleMessages = require("../../utils/ruleMessages");
+const validateOptions = require("../../utils/validateOptions");
+
+const ruleName = "font-family-no-duplicate-names";
+
+const messages = ruleMessages(ruleName, {
+ rejected: name => `Unexpected duplicate name ${name}`
+});
+
+const isFamilyNameKeyword = node =>
+ !node.quote && keywordSets.fontFamilyKeywords.has(node.value.toLowerCase());
+
+const rule = function(actual, options) {
+ return (root, result) => {
+ const validOptions = validateOptions(
+ result,
+ ruleName,
+ { actual },
+ {
+ actual: options,
+ possible: {
+ ignoreFontFamilyNames: [_.isString]
+ },
+ optional: true
+ }
+ );
+ if (!validOptions) {
+ return;
+ }
+
+ root.walkDecls(/^font(-family)?$/i, decl => {
+ const keywords = new Set();
+ const familyNames = new Set();
+
+ const fontFamilies = findFontFamily(decl.value);
+
+ if (fontFamilies.length === 0) {
+ return;
+ }
+
+ fontFamilies.forEach(fontFamilyNode => {
+ const family = fontFamilyNode.value.trim();
+
+ if (
+ optionsMatches(
+ options,
+ "ignoreFontFamilyNames",
+ fontFamilyNode.value.trim()
+ )
+ ) {
+ return;
+ }
+
+ if (isFamilyNameKeyword(fontFamilyNode)) {
+ if (keywords.has(family.toLowerCase())) {
+ complain(
+ messages.rejected(family),
+ declarationValueIndex(decl) + fontFamilyNode.sourceIndex,
+ decl
+ );
+ return;
+ }
+
+ keywords.add(family);
+ return;
+ }
+
+ if (familyNames.has(family)) {
+ complain(
+ messages.rejected(family),
+ declarationValueIndex(decl) + fontFamilyNode.sourceIndex,
+ decl
+ );
+ return;
+ }
+
+ familyNames.add(family);
+ });
+ });
+
+ function complain(message, index, decl) {
+ report({
+ result,
+ ruleName,
+ message,
+ node: decl,
+ index
+ });
+ }
+ };
+};
+
+rule.ruleName = ruleName;
+rule.messages = messages;
+module.exports = rule;