Fix element classNames/ids for objects when using classIdPrefix property

The classIdPrefix would previously add the '.className' version of the
class to both the style class and the rendered react component. Instead
only include the prefix (. or #) for the style, not the actual elements.

Author: Sam Shelley

lib/sanitize/filters/prefix-style-class-id.js

@@ -26,9 +26,10 @@ function processStyles (opts, source) {
                         replace(
                             CLASSNAME_OR_ID_SELECTOR_REGEX,
                             function (match, pre, post) {
-                                var newname = pre + opts.prefix + post;
-                                opts.cache[post] = newname;
-                                return newname;
+                                // Set the cached version to not include the prefix (the dot) so that the className or id
+                                // is 'className' instead of '.className'
+                                opts.cache[post] = opts.prefix + post;
+                                return pre + opts.prefix + post;
                             }
                         );
                 });

test/unit/xml/parse.js

@@ -177,7 +177,7 @@ describe('svg-react-loader/lib/xml/parse', () => {
                                                 {
                                                     tagname: 'path',
                                                     props: {
-                                                        className: ".styles-test__st0",
+                                                        className: "styles-test__st0",
                                                         d: "M14.5,18v2h21v-2H14.5z M14.5,26h21v-2h-21V26z M14.5,32h21v-2h-21V32z"
                                                     }
                                                 }