--- /dev/null
+"use strict";
+
+const _ = require("lodash");
+const declarationValueIndex = require("../../utils/declarationValueIndex");
+const isStandardSyntaxFunction = require("../../utils/isStandardSyntaxFunction");
+const keywordSets = require("../../reference/keywordSets");
+const matchesStringOrRegExp = require("../../utils/matchesStringOrRegExp");
+const report = require("../../utils/report");
+const ruleMessages = require("../../utils/ruleMessages");
+const validateOptions = require("../../utils/validateOptions");
+const valueParser = require("postcss-value-parser");
+
+const ruleName = "function-name-case";
+
+const messages = ruleMessages(ruleName, {
+ expected: (actual, expected) => `Expected "${actual}" to be "${expected}"`
+});
+
+const mapLowercaseFunctionNamesToCamelCase = new Map();
+keywordSets.camelCaseFunctionNames.forEach(func => {
+ mapLowercaseFunctionNamesToCamelCase.set(func.toLowerCase(), func);
+});
+
+const rule = function(expectation, options) {
+ return (root, result) => {
+ const validOptions = validateOptions(
+ result,
+ ruleName,
+ {
+ actual: expectation,
+ possible: ["lower", "upper"]
+ },
+ {
+ actual: options,
+ possible: {
+ ignoreFunctions: [_.isString]
+ },
+ optional: true
+ }
+ );
+ if (!validOptions) {
+ return;
+ }
+
+ root.walkDecls(decl => {
+ const value = decl.value;
+
+ valueParser(value).walk(function(node) {
+ if (node.type !== "function" || !isStandardSyntaxFunction(node)) {
+ return;
+ }
+
+ const functionName = node.value;
+ const functionNameLowerCase = functionName.toLowerCase();
+
+ const ignoreFunctions = (options && options.ignoreFunctions) || [];
+
+ if (
+ ignoreFunctions.length > 0 &&
+ matchesStringOrRegExp(functionName, ignoreFunctions)
+ ) {
+ return;
+ }
+
+ let expectedFunctionName = null;
+
+ if (
+ expectation === "lower" &&
+ mapLowercaseFunctionNamesToCamelCase.has(functionNameLowerCase)
+ ) {
+ expectedFunctionName = mapLowercaseFunctionNamesToCamelCase.get(
+ functionNameLowerCase
+ );
+ } else if (expectation === "lower") {
+ expectedFunctionName = functionNameLowerCase;
+ } else {
+ expectedFunctionName = functionName.toUpperCase();
+ }
+
+ if (functionName === expectedFunctionName) {
+ return;
+ }
+
+ report({
+ message: messages.expected(functionName, expectedFunctionName),
+ node: decl,
+ index: declarationValueIndex(decl) + node.sourceIndex,
+ result,
+ ruleName
+ });
+ });
+ });
+ };
+};
+
+rule.ruleName = ruleName;
+rule.messages = messages;
+module.exports = rule;