--- /dev/null
+"use strict";
+
+const _ = require("lodash");
+const functionArgumentsSearch = require("../../utils/functionArgumentsSearch");
+const getSchemeFromUrl = require("../../utils/getSchemeFromUrl");
+const isStandardSyntaxUrl = require("../../utils/isStandardSyntaxUrl");
+const matchesStringOrRegExp = require("../../utils/matchesStringOrRegExp");
+const report = require("../../utils/report");
+const ruleMessages = require("../../utils/ruleMessages");
+const validateOptions = require("../../utils/validateOptions");
+
+const ruleName = "function-url-scheme-whitelist";
+
+const messages = ruleMessages(ruleName, {
+ rejected: scheme => `Unexpected URL scheme "${scheme}:"`
+});
+
+const rule = function(whitelist) {
+ return (root, result) => {
+ const validOptions = validateOptions(result, ruleName, {
+ actual: whitelist,
+ possible: [_.isString]
+ });
+ if (!validOptions) {
+ return;
+ }
+
+ root.walkDecls(function(decl) {
+ functionArgumentsSearch(
+ decl.toString().toLowerCase(),
+ "url",
+ (args, index) => {
+ const unspacedUrlString = _.trim(args, " ");
+ if (!isStandardSyntaxUrl(unspacedUrlString)) {
+ return;
+ }
+ const urlString = _.trim(unspacedUrlString, "'\"");
+ const scheme = getSchemeFromUrl(urlString);
+
+ if (scheme === null) {
+ return;
+ }
+
+ if (matchesStringOrRegExp(scheme, whitelist)) {
+ return;
+ }
+
+ report({
+ message: messages.rejected(scheme),
+ node: decl,
+ index,
+ result,
+ ruleName
+ });
+ }
+ );
+ });
+ };
+};
+
+rule.primaryOptionArray = true;
+
+rule.ruleName = ruleName;
+rule.messages = messages;
+module.exports = rule;