--- /dev/null
+"use strict";
+
+const ruleMessages = require("../../utils/ruleMessages");
+const validateOptions = require("../../utils/validateOptions");
+const valueListCommaWhitespaceChecker = require("../valueListCommaWhitespaceChecker");
+const whitespaceChecker = require("../../utils/whitespaceChecker");
+
+const ruleName = "value-list-comma-space-before";
+
+const messages = ruleMessages(ruleName, {
+ expectedBefore: () => 'Expected single space before ","',
+ rejectedBefore: () => 'Unexpected whitespace before ","',
+ expectedBeforeSingleLine: () =>
+ 'Unexpected whitespace before "," in a single-line list',
+ rejectedBeforeSingleLine: () =>
+ 'Unexpected whitespace before "," in a single-line list'
+});
+
+const rule = function(expectation) {
+ const checker = whitespaceChecker("space", expectation, messages);
+ return (root, result) => {
+ const validOptions = validateOptions(result, ruleName, {
+ actual: expectation,
+ possible: ["always", "never", "always-single-line", "never-single-line"]
+ });
+ if (!validOptions) {
+ return;
+ }
+
+ valueListCommaWhitespaceChecker({
+ root,
+ result,
+ locationChecker: checker.before,
+ checkedRuleName: ruleName
+ });
+ };
+};
+
+rule.ruleName = ruleName;
+rule.messages = messages;
+module.exports = rule;