From 87560305ec271fee51fd1afcf9238a7e31767a54 Mon Sep 17 00:00:00 2001
From: Eoghan Murray <eoghan@getthere.ie>
Date: Fri, 29 Nov 2024 20:20:10 +0000
Subject: [PATCH] Apply adaption even if split is within something that needs
 to be adapted

---
 .changeset/fix-adapt-css.md              |  6 ++
 packages/rrweb-snapshot/src/rebuild.ts   | 82 ++++++++----------------
 packages/rrweb-snapshot/test/css.test.ts |  7 +-
 3 files changed, 38 insertions(+), 57 deletions(-)
 create mode 100644 .changeset/fix-adapt-css.md

diff --git a/.changeset/fix-adapt-css.md b/.changeset/fix-adapt-css.md
new file mode 100644
index 0000000000..3564086a8c
--- /dev/null
+++ b/.changeset/fix-adapt-css.md
@@ -0,0 +1,6 @@
+---
+'rrweb': patch
+'rrweb-snapshot': patch
+---
+
+#1575 Fix that postcss could fall over when trying to process css content split arbitrarily
diff --git a/packages/rrweb-snapshot/src/rebuild.ts b/packages/rrweb-snapshot/src/rebuild.ts
index 7d92ba8199..74cae08d55 100644
--- a/packages/rrweb-snapshot/src/rebuild.ts
+++ b/packages/rrweb-snapshot/src/rebuild.ts
@@ -104,65 +104,39 @@ export function applyCssSplits(
     // unexpected: remerge the last two so that we don't discard any css
     cssTextSplits.splice(-2, 2, cssTextSplits.slice(-2).join(''));
   }
-  let adaptionFailures = [];
+  let adaptedCss = '';
+  if (hackCss) {
+    adaptedCss = adaptCssForReplay(cssTextSplits.join(''), cache);
+  }
+  let ix_start = 0;
   for (let i = 0; i < childTextNodes.length; i++) {
     const childTextNode = childTextNodes[i];
-    let cssTextSection = cssTextSplits[i];
-    if (childTextNode && cssTextSection) {
-      // id will be assigned when these child nodes are
-      // iterated over in buildNodeWithSN
-      if (hackCss) {
-        try {
-          cssTextSection = adaptCssForReplay(cssTextSection, cache);
-        } catch (e) {
-          // css section might not have been valid on it's own
-          adaptionFailures.push(i);
-        }
+    if (!hackCss) {
+      if (i === cssTextSplits.length) {
+        break;
       }
-      childTextNode.textContent = cssTextSection;
-    }
-  }
-  if (adaptionFailures.length) {
-    // this time, can throw an exception
-    const fullAdaptedCss = adaptCssForReplay(cssTextSplits.join(''), cache);
-    let ix_start = 0;
-    for (let i = 0; i < childTextNodes.length; i++) {
-      const childTextNode = childTextNodes[i];
-      if (adaptionFailures.includes(i)) {
-        if (i === childTextNodes.length - 1) {
-          console.log('he' + i, ix_start, fullAdaptedCss.substring(ix_start));
-          childTextNode.textContent = fullAdaptedCss.substring(ix_start);
-        } else {
-          let ix_end = -1;
-          let end_search = childTextNodes[i + 1].textContent.length;
-          while (ix_end === -1) {
-            let search_bit = childTextNodes[i + 1].textContent.substring(
-              0,
-              end_search,
-            );
-            ix_end =
-              ix_start + fullAdaptedCss.substring(ix_start).indexOf(search_bit);
-            end_search -= 1;
-            if (end_search <= 2) {
-              break;
-            }
-          }
-          console.log(
-            're' + i,
-            ix_start,
-            ix_end,
-            fullAdaptedCss.substring(ix_start, ix_end),
-          );
-          if (ix_end !== -1) {
-            childTextNode.textContent = fullAdaptedCss.substring(
-              ix_start,
-              ix_end,
-            );
-          } else {
-          }
+      childTextNode.textContent = cssTextSplits[i];
+    } else if (i < childTextNodes.length - 1) {
+      let ix_end = -1;
+      let end_search = cssTextSplits[i + 1].length;
+      while (ix_end === -1) {
+        let search_bit = cssTextSplits[i + 1].substring(0, end_search);
+        ix_end = ix_start + adaptedCss.substring(ix_start).indexOf(search_bit);
+        if (ix_end === -1) {
+          end_search -= 1;
+          continue;
+        } else if (ix_end <= 2) {
+          break;
         }
       }
-      ix_start += childTextNode.textContent.length;
+      if (ix_end === -1) {
+        // something went wrong, put a similar sized chunk in the right place
+        ix_end = ix_start + cssTextSplits[i].length;
+      }
+      childTextNode.textContent = adaptedCss.substring(ix_start, ix_end);
+      ix_start = ix_end;
+    } else {
+      childTextNode.textContent = adaptedCss.substring(ix_start);
     }
   }
 }
diff --git a/packages/rrweb-snapshot/test/css.test.ts b/packages/rrweb-snapshot/test/css.test.ts
index 0909e2161c..d4bf522949 100644
--- a/packages/rrweb-snapshot/test/css.test.ts
+++ b/packages/rrweb-snapshot/test/css.test.ts
@@ -236,9 +236,10 @@ describe('applyCssSplits css rejoiner', function () {
     const badSecondHalf = 'er { color: red; }';
     const markedCssText = [badFirstHalf, badSecondHalf].join('/* rr_split */');
     applyCssSplits(sn, markedCssText, true, mockLastUnusedArg);
-    expect((sn.childNodes[1] as textNode).textContent).toEqual(
-      'er,\na.\\:hover { color: red; }',
-    );
+    expect(
+      (sn.childNodes[0] as textNode).textContent +
+        (sn.childNodes[1] as textNode).textContent,
+    ).toEqual('a:hover,\na.\\:hover { color: red; }');
   });
 
   it('applies css splits correctly when split parts are invalid by themselves x3', () => {