From c9eb1a17b922c8a6d56b5cf765800b0dd8865155 Mon Sep 17 00:00:00 2001
From: Christian Rey Villablanca <chriztiann.villablanca@gmail.com>
Date: Thu, 6 Aug 2026 23:03:08 +0800
Subject: [PATCH] fix(chat): preserve session model selection

---
 src/providers/ChatViewProvider.ts             |  6 ++--
 ...ession-model-selection-regression.test.mjs | 32 +++++++++++++++++++
 2 files changed, 36 insertions(+), 2 deletions(-)
 create mode 100644 tests/regression/session-model-selection-regression.test.mjs

diff --git a/src/providers/ChatViewProvider.ts b/src/providers/ChatViewProvider.ts
index ba3d039..b503068 100644
--- a/src/providers/ChatViewProvider.ts
+++ b/src/providers/ChatViewProvider.ts
@@ -2008,7 +2008,7 @@ export class ChatViewProvider
       this.clearSessionTodos(sessionId);
 
       // Restore per-session agent / model / thinking selections
-      await this.modelAndAgentManager.applySessionSettings(sessionId);
+      await this.applySessionSettings(sessionId);
       if (abandonIfStale("applySessionSettings")) return;
 
       // ============================================================================
@@ -9288,7 +9288,9 @@ export class ChatViewProvider
    * Applies session-specific model, agent, and thinking level
    */
   private async applySessionSettings(sessionId: string): Promise<void> {
-    return this.modelAndAgentManager.applySessionSettings(sessionId);
+    await this.modelAndAgentManager.applySessionSettings(sessionId);
+    this.selectedModel = this.modelAndAgentManager.getSelectedModel();
+    this.selectedAgent = this.modelAndAgentManager.getSelectedAgent() ?? "build";
   }
 
   /**
diff --git a/tests/regression/session-model-selection-regression.test.mjs b/tests/regression/session-model-selection-regression.test.mjs
new file mode 100644
index 0000000..742608d
--- /dev/null
+++ b/tests/regression/session-model-selection-regression.test.mjs
@@ -0,0 +1,32 @@
+import assert from "node:assert/strict";
+import test from "node:test";
+
+import { extractFunctionBody, joinFromRoot, readSource } from "../helpers/source-utils.mjs";
+
+const provider = readSource(
+  [joinFromRoot("src", "providers", "ChatViewProvider.ts")],
+  "ChatViewProvider.ts",
+);
+
+test("session switches synchronize the prompt model with restored session settings", () => {
+  const applySessionSettings = extractFunctionBody(
+    provider,
+    "private async applySessionSettings(sessionId: string): Promise<void>",
+  );
+
+  assert.match(
+    applySessionSettings,
+    /await this\.modelAndAgentManager\.applySessionSettings\(sessionId\)/,
+    "session settings must be restored before synchronizing prompt state",
+  );
+  assert.match(
+    applySessionSettings,
+    /this\.selectedModel\s*=\s*this\.modelAndAgentManager\.getSelectedModel\(\)/,
+    "prompts must use the model restored for the active session",
+  );
+  assert.match(
+    provider,
+    /await this\.applySessionSettings\(sessionId\);/,
+    "session loading must use the synchronized restore path",
+  );
+});