feat: warn if trying to add malformed CSS

Author: feildmaster

src/base/plugin/addStyle.js

@@ -14,7 +14,7 @@ wrap(() => {
   }
 
   function mod(plugin) {
-    return (...styles) => getStyle(plugin.name).add(...styles);
+    return (...styles) => getStyle(plugin).add(...styles);
   }
 
   registerModule(name, mod);

src/utils/charCount.js

@@ -0,0 +1,5 @@
+export default function charCount(string = '', char = '') {
+  const regex = new RegExp(char, 'g');
+  const matches = string.match(regex);
+  return matches?.length ?? 0;
+}

src/utils/style.js

@@ -1,3 +1,4 @@
+import charCount from './charCount.js';
 import eventManager from './eventManager.js';
 import last from './last.js';
 
@@ -7,7 +8,7 @@ export function newStyle(plugin = false) {
   const el = document.createElement('style');
   function appendStyle() {
     if (el.parentElement) return;
-    if (plugin) el.dataset.underscriptPlugin = plugin;
+    if (plugin) el.dataset.underscriptPlugin = plugin.name;
     else el.dataset.underscript = '';
     document.head.append(el);
   }
@@ -26,6 +27,11 @@ export function newStyle(plugin = false) {
 
   function append(styles = [], nodes = []) {
     styles.flat().forEach((s) => {
+      if (charCount(s, '{') !== charCount(s, '}')) {
+        const logger = plugin?.logger ?? console;
+        logger.error('Malformed CSS (missing { or }):\n', s);
+        return;
+      }
       el.append(s);
       nodes.push(last(el.childNodes));
     });