Chat: prefer active model for new desktop chats

tests/test_new_chat_model_preference.py

@@ -0,0 +1,44 @@
+from pathlib import Path
+
+
+APP_JS = Path("static/app.js")
+
+
+def _slice(source, start_marker, end_marker):
+    start = source.index(start_marker)
+    end = source.index(end_marker, start)
+    return source[start:end]
+
+
+def test_new_chat_prefers_pending_and_current_model_before_default():
+    source = APP_JS.read_text(encoding="utf-8")
+    helper = _slice(
+        source,
+        "async function _createDirectChatFromPreferredModel()",
+        "// ============================================",
+    )
+
+    default_pos = helper.index("const dc = await _refreshDefaultChat();")
+    assert helper.index("sessionModule.getPendingChat") < default_pos
+    assert helper.index("current.endpoint_url") < default_pos
+    assert default_pos < helper.index("const withModel = sessions.filter")
+
+
+def test_desktop_new_chat_actions_use_shared_preference_helper():
+    source = APP_JS.read_text(encoding="utf-8")
+
+    rail_handler = _slice(
+        source,
+        "// New session button on icon rail",
+        "// Mobile new chat button",
+    )
+    brand_handler = _slice(
+        source,
+        "// Logo click \u2192 new chat",
+        "const sidebarNewChatBtn = el('sidebar-new-chat-btn');",
+    )
+
+    assert "if (await _createDirectChatFromPreferredModel()) return;" in rail_handler
+    assert "if (await _createDirectChatFromPreferredModel()) return;" in brand_handler
+    assert "const dc = await _refreshDefaultChat();" not in rail_handler
+    assert "const dc = await _refreshDefaultChat();" not in brand_handler