Avoid (probably) a happydom bug

packages/rrweb-snapshot/test/css.test.ts

@@ -238,11 +238,13 @@ describe('css splitter', () => {
 .section-news-v3-detail .news-cnt-wrapper .plugins-wrapper2 :where(.prose > :first-child):not(:where([class~="not-prose"],[cl</style>`;
     const style = document.querySelector('style');
     if (style) {
+      // happydom? bug avoid: strangely a greater than symbol in the template string below
+      // e.g. '.prose > :last-child' causes more than one child to be appended
       style.append(`ass~="not-prose"] *)) {
     margin-top: 0;
 }
 
-.section-news-v3-detail .news-cnt-wrapper .plugins-wrapper2 :where(.prose > :last-child):not(:where([class~="not-prose"],[class~="not-prose"] *)) {
+.section-news-v3-detail .news-cnt-wrapper .plugins-wrapper2 :where(.prose :last-child):not(:where([class~="not-prose"],[class~="not-prose"] *)) {
     margin-bottom: 0;
 }
 
@@ -257,9 +259,11 @@ describe('css splitter', () => {
 }
 `);
 
+      expect(style.childNodes.length).toEqual(2);
+
       const expected = [
         '.section-news-v3-detail .news-cnt-wrapper .plugins-wrapper2 :where(figure):not(:where([class~="not-prose"],[class~="not-prose"] *)) { margin-top: 2em; margin-bottom: 2em; }.section-news-v3-detail .news-cnt-wrapper .plugins-wrapper2 :where(.prose > :first-child):not(:where([class~="not-prose"],[cl',
-        'ass~="not-prose"] *)) { margin-top: 0px; }.section-news-v3-detail .news-cnt-wrapper .plugins-wrapper2 :where(.prose > :last-child):not(:where([class~="not-prose"],[class~="not-prose"] *)) { margin-bottom: 0px; }.section-news-v3-detail .news-cnt-wrapper .plugins-wrapper2 { width: 100%; overflow-wrap: break-word; }.section-home { height: 100%; overflow-y: auto; }',
+        'ass~="not-prose"] *)) { margin-top: 0px; }.section-news-v3-detail .news-cnt-wrapper .plugins-wrapper2 :where(.prose :last-child):not(:where([class~="not-prose"],[class~="not-prose"] *)) { margin-bottom: 0px; }.section-news-v3-detail .news-cnt-wrapper .plugins-wrapper2 { width: 100%; overflow-wrap: break-word; }.section-home { height: 100%; overflow-y: auto; }',
       ];
       const browserSheet = expected.join('');
       expect(stringifyStylesheet(style.sheet!)).toEqual(browserSheet);