From 9a397f1976bb90042fce441d53b246e854ca7e32 Mon Sep 17 00:00:00 2001
From: Matt Brophy <matt@brophy.org>
Date: Wed, 22 Mar 2023 11:11:06 -0400
Subject: [PATCH 1/2] Remove instanceof check for DeferredData

---
 .changeset/rotten-waves-fold.md |  5 +++++
 packages/router/router.ts       | 14 +++++++++++++-
 2 files changed, 18 insertions(+), 1 deletion(-)
 create mode 100644 .changeset/rotten-waves-fold.md

diff --git a/.changeset/rotten-waves-fold.md b/.changeset/rotten-waves-fold.md
new file mode 100644
index 0000000000..f2107e9271
--- /dev/null
+++ b/.changeset/rotten-waves-fold.md
@@ -0,0 +1,5 @@
+---
+"@remix-run/router": patch
+---
+
+Remove `instanceof` check for `DeferredData` to be resiliant to ESM/CJS boundaries in SSR bundling scenarios
diff --git a/packages/router/router.ts b/packages/router/router.ts
index 575b8e2a85..e2e55fe1d2 100644
--- a/packages/router/router.ts
+++ b/packages/router/router.ts
@@ -3486,7 +3486,7 @@ async function callLoaderOrAction(
     return { type: resultType, error: result };
   }
 
-  if (result instanceof DeferredData) {
+  if (isDeferredData(result)) {
     return {
       type: ResultType.deferred,
       deferredData: result,
@@ -3856,6 +3856,18 @@ function isRedirectResult(result?: DataResult): result is RedirectResult {
   return (result && result.type) === ResultType.redirect;
 }
 
+export function isDeferredData(value: any): value is DeferredData {
+  let deferred: DeferredData = value;
+  return (
+    deferred &&
+    typeof deferred === "object" &&
+    typeof deferred.data === "object" &&
+    typeof deferred.subscribe === "function" &&
+    typeof deferred.cancel === "function" &&
+    typeof deferred.resolveData === "function"
+  );
+}
+
 function isResponse(value: any): value is Response {
   return (
     value != null &&

From 31e3c39fea107fb1325458751029661a91eda171 Mon Sep 17 00:00:00 2001
From: Matt Brophy <matt@brophy.org>
Date: Wed, 22 Mar 2023 11:15:02 -0400
Subject: [PATCH 2/2] Bump bundle

---
 package.json | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/package.json b/package.json
index de947bd2eb..c930322687 100644
--- a/package.json
+++ b/package.json
@@ -105,7 +105,7 @@
   },
   "filesize": {
     "packages/router/dist/router.umd.min.js": {
-      "none": "43.1 kB"
+      "none": "43.3 kB"
     },
     "packages/react-router/dist/react-router.production.min.js": {
       "none": "13 kB"