From 690a9c98334db8eafd099f1605fd3561de8ee867 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nacho=20Codo=C3=B1er?= <igcogi@gmail.com>
Date: Mon, 20 Apr 2026 11:35:09 +0200
Subject: [PATCH] prevent `.cache` directory from being copied during
 node_modules bundling; ensure consistent filtering through absolute path
 checks

---
 tools/isobuild/builder.js | 28 +++++++++++++++++-----------
 1 file changed, 17 insertions(+), 11 deletions(-)

diff --git a/tools/isobuild/builder.js b/tools/isobuild/builder.js
index d0afb2b41b..ff74ccbf75 100644
--- a/tools/isobuild/builder.js
+++ b/tools/isobuild/builder.js
@@ -538,28 +538,35 @@ Previous builder: ${previousBuilder.outputPath}, this builder: ${outputPath}`
     // assert.strictEqual(files.pathBasename(options.from), "node_modules");
     assert.strictEqual(files.pathBasename(options.to), "node_modules");
 
+    const absFrom = realpath(options.from);
+    // Bundler scratch written during the build; transient and not part
+    // of the bundle. Matched by absolute path so a `.cache/` shipped
+    // inside a published package isn't dropped.
+    const rootCache = files.pathJoin(absFrom, ".cache");
+
     if (options.symlink) {
       // If we're going to use symlinks to speed up this copy, then we
       // need to make sure we've reserved all directories that are not
       // package directories, such as the node_modules directory itself,
       // as well as node_modules/meteor and the parent directories of any
       // scoped npm packages.
-      this._ensureAllNonPackageDirectories(
-        realpath(options.from),
-        options.to
-      );
+      this._ensureAllNonPackageDirectories(absFrom, options.to, rootCache);
     }
 
-    // Exclude node_modules/.cache: transient bundler scratch space that
-    // races with readdir (ENOENT) and doesn't belong in the bundle.
+    const userFilter = options.filter;
     // Call this._copyDirectory rather than this.copyDirectory so that the
     // subBuilder hacks from Builder#enter won't apply a second time.
     return this._copyDirectory(Object.assign({}, options, {
-      ignore: [/^\.cache\/$/].concat(options.ignore || []),
+      filter: (absPath, isDirectory) => {
+        if (isDirectory && absPath === rootCache) return false;
+        return userFilter ? userFilter(absPath, isDirectory) : true;
+      },
     }));
   }
 
-  _ensureAllNonPackageDirectories(absFromDir, relToDir) {
+  _ensureAllNonPackageDirectories(absFromDir, relToDir, skipPath) {
+    if (skipPath && absFromDir === skipPath) return;
+
     const dirStat = optimisticStatOrNull(absFromDir);
     if (! (dirStat && dirStat.isDirectory())) {
       return;
@@ -589,11 +596,10 @@ Previous builder: ${previousBuilder.outputPath}, this builder: ${outputPath}`
     }
 
     entries.forEach(item => {
-      // Skip node_modules/.cache (see copyNodeModulesDirectory).
-      if (item === ".cache") return;
       this._ensureAllNonPackageDirectories(
         files.pathJoin(absFromDir, item),
-        files.pathJoin(relToDir, item)
+        files.pathJoin(relToDir, item),
+        skipPath
       );
     });
   }