From 4124abe7246daf665eb81c4403a88145cb97aad6 Mon Sep 17 00:00:00 2001
From: Valeri Karpov <val@karpov.io>
Date: Fri, 5 Apr 2024 11:07:14 -0400
Subject: [PATCH 1/3] fix(mongoose): make setDriver() update mongoose.model()
 connections and collections

---
 lib/model.js    | 22 ++++++++++++++++++++++
 lib/mongoose.js | 10 ++++++++++
 2 files changed, 32 insertions(+)

diff --git a/lib/model.js b/lib/model.js
index f5e4f12f967..4169e434e50 100644
--- a/lib/model.js
+++ b/lib/model.js
@@ -4893,6 +4893,28 @@ Model.compile = function compile(name, schema, collectionName, connection, base)
   return model;
 };
 
+/*!
+ * ignore
+ */
+
+Model.$__updateConnection = function $__updateConnection(newConnection) {
+  this.db = newConnection;
+  this.prototype.db = newConnection;
+  this.prototype[modelDbSymbol] = newConnection;
+
+  const collection = newConnection.collection(
+    this.collection.collectionName,
+    this.collection.opts
+  );
+
+  this.prototype.collection = collection;
+  this.prototype.$collection = collection;
+  this.prototype[modelCollectionSymbol] = collection;
+
+  this.collection = collection;
+  this.$__collection = collection;
+};
+
 /**
  * Register custom query methods for this model
  *
diff --git a/lib/mongoose.js b/lib/mongoose.js
index fba35284838..c22f2db013e 100644
--- a/lib/mongoose.js
+++ b/lib/mongoose.js
@@ -166,9 +166,19 @@ Mongoose.prototype.setDriver = function setDriver(driver) {
   _mongoose.__driver = driver;
 
   const Connection = driver.Connection;
+  const oldDefaultConnection = _mongoose.connections[0];
   _mongoose.connections = [new Connection(_mongoose)];
   _mongoose.connections[0].models = _mongoose.models;
 
+  // Update all models that pointed to the old default connection to
+  // the new default connection, including collections
+  for (const model of Object.values(_mongoose.models)) {
+    if (model.connection !== oldDefaultConnection) {
+      continue;
+    }
+    model.$__updateConnection(_mongoose.connections[0]);
+  }
+
   return _mongoose;
 };
 

From c68fcfd90dfcee646c483475dd4762f331c8f2f3 Mon Sep 17 00:00:00 2001
From: Valeri Karpov <val@karpov.io>
Date: Fri, 5 Apr 2024 16:39:26 -0400
Subject: [PATCH 2/3] fix: correctly access connection

---
 lib/mongoose.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/mongoose.js b/lib/mongoose.js
index c22f2db013e..97475a76868 100644
--- a/lib/mongoose.js
+++ b/lib/mongoose.js
@@ -173,7 +173,7 @@ Mongoose.prototype.setDriver = function setDriver(driver) {
   // Update all models that pointed to the old default connection to
   // the new default connection, including collections
   for (const model of Object.values(_mongoose.models)) {
-    if (model.connection !== oldDefaultConnection) {
+    if (model.db !== oldDefaultConnection) {
       continue;
     }
     model.$__updateConnection(_mongoose.connections[0]);

From 9fb1d81fc1e81a8523aead9c9fea800bec5fd3af Mon Sep 17 00:00:00 2001
From: Valeri Karpov <val@karpov.io>
Date: Sun, 7 Apr 2024 17:30:04 -0400
Subject: [PATCH 3/3] docs(model): add comments for $__updateConnection

---
 lib/model.js | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/lib/model.js b/lib/model.js
index 4169e434e50..f6c21f6670e 100644
--- a/lib/model.js
+++ b/lib/model.js
@@ -4893,8 +4893,14 @@ Model.compile = function compile(name, schema, collectionName, connection, base)
   return model;
 };
 
-/*!
- * ignore
+/**
+ * Update this model to use the new connection, including updating all internal
+ * references and creating a new `COllection` instance using the new connection.
+ * Not for external use, only used by `setDriver()` to ensure that you can still
+ * call `setDriver()` after creating a model using `mongoose.model()`.
+ *
+ * @param {Connection} newConnection the new connection to use
+ * @api private
  */
 
 Model.$__updateConnection = function $__updateConnection(newConnection) {