Add support for camel-case properties

...because the CLI parses argv arguments and camelizes them.

Closes GH-25.

lib/index.js

@@ -13,6 +13,7 @@
  * Dependencies.
  */
 
+var decamelize = require('decamelize');
 var sort = require('vfile-sort');
 var range = require('mdast-range');
 var zone = require('mdast-zone');
@@ -172,6 +173,24 @@ function loadExternals(externals) {
  return rules;
 }
 
+/**
+ * Helper to ensure ruleId’s are dash-cased instead of
+ * camel-cased.
+ *
+ * @param {Object} source - Original settings.
+ * @return {Object} - Dash-cased settings.
+ */
+function decamelizeSettings(source) {
+ var result = {};
+ var key;
+
+ for (key in source) {
+ result[decamelize(key, '-')] = source[key];
+ }
+
+ return result;
+}
+
 /**
  * Lint attacher.
  *
@@ -190,7 +209,7 @@ function loadExternals(externals) {
  * rule options.
  */
 function lint(mdast, options) {
- var settings = options || {};
+ var settings = decamelizeSettings(options || {});
  var reset = settings.reset;
  var rules = loadExternals(settings.external);
  var id;