Fix memo component ordering and Var-backed page title handling

Move memo component compilation after app_root resolution so app-wrap
components are included. Fix DefaultPagePlugin to preserve Var-backed
titles instead of replacing them with the default string.

Author: FarhanAliRaza

reflex/compiler/compiler.py

@@ -1085,18 +1085,6 @@ def compile_app(
     ]
     all_imports = compile_ctx.all_imports
 
-    (
-        memo_components_output,
-        memo_components_result,
-        memo_components_imports,
-    ) = compile_memo_components(
-        dict.fromkeys(CUSTOM_COMPONENTS.values()),
-        tuple(EXPERIMENTAL_MEMOS.values()),
-    )
-    compile_results.append((memo_components_output, memo_components_result))
-    all_imports = utils.merge_imports(all_imports, memo_components_imports)
-    progress.advance(task)
-
     if (
         code_uses_state_contexts(compile_ctx.stateful_components_code)
         and app._state is None
@@ -1117,6 +1105,18 @@ def compile_app(
     app_root = app._app_root(app_wrappers)
     all_imports = utils.merge_imports(all_imports, app_root._get_all_imports())
 
+    (
+        memo_components_output,
+        memo_components_result,
+        memo_components_imports,
+    ) = compile_memo_components(
+        dict.fromkeys(CUSTOM_COMPONENTS.values()),
+        tuple(EXPERIMENTAL_MEMOS.values()),
+    )
+    compile_results.append((memo_components_output, memo_components_result))
+    all_imports = utils.merge_imports(all_imports, memo_components_imports)
+    progress.advance(task)
+
     compile_results.append(
         compile_document_root(
             app.head_components,

reflex/compiler/plugins/builtin.py

@@ -53,9 +53,13 @@ def eval_page(
             component = compiler.into_component(page_fn)
             component = Fragment.create(component)
 
+            title = getattr(page, "title", None)
             meta_args = {
-                "title": getattr(page, "title", None)
-                or make_default_page_title(get_config().app_name, page.route),
+                "title": (
+                    title
+                    if title is not None
+                    else make_default_page_title(get_config().app_name, page.route)
+                ),
                 "image": getattr(page, "image", ""),
                 "meta": getattr(page, "meta", ()),
             }

tests/units/compiler/test_plugins.py

@@ -25,6 +25,7 @@
 )
 from reflex_core.utils import format as format_utils
 from reflex_core.utils.imports import ImportVar, collapse_imports, merge_imports
+from reflex_core.vars.base import Var
 
 from reflex.app import UnevaluatedPage
 from reflex.compiler import compiler
@@ -40,8 +41,8 @@
 class FakePage:
     route: str
     component: Callable[[], Component]
-    title: str | None = None
-    description: str | None = None
+    title: Var | str | None = None
+    description: Var | str | None = None
     image: str = ""
     meta: tuple[dict[str, Any], ...] = ()
 
@@ -790,6 +791,38 @@ def test_compile_context_compiles_pages_and_matches_legacy_output() -> None:
     assert page_ctx.output_code == expected_output
 
 
+def test_default_page_plugin_handles_var_backed_title_like_legacy_compiler() -> None:
+    page = UnevaluatedPage(
+        component=lambda: Fragment.create(),
+        route="/var-title",
+        title=Var(_js_expr="pageTitle", _var_type=str),
+        description=None,
+        image="",
+        on_load=None,
+        meta=(),
+        context={},
+    )
+    hooks = CompilerHooks(plugins=(DefaultPagePlugin(),))
+    compile_ctx = create_compile_context(hooks)
+
+    with compile_ctx:
+        page_ctx = hooks.eval_page(
+            page.component,
+            page=page,
+            compile_context=compile_ctx,
+        )
+
+    assert page_ctx is not None
+
+    legacy_component = compiler.compile_unevaluated_page(
+        page.route,
+        page,
+        None,
+        None,
+    )
+    assert page_ctx.root_component.render() == legacy_component.render()
+
+
 def test_compile_context_rejects_duplicate_routes() -> None:
     pages = [
         FakePage(route="/duplicate", component=lambda: Fragment.create()),

tests/units/test_app.py

@@ -2085,6 +2085,28 @@ def test_app_wrap_compile_theme(
     assert expected.split(",") == function_app_definition.split(",")
 
 
+def test_compile_writes_app_wrap_memo_components(
+    compilable_app: tuple[App, Path],
+    mocker,
+) -> None:
+    """App-wrap memo components are emitted to the shared components module."""
+    conf = rx.Config(app_name="testing")
+    mocker.patch("reflex_core.config._get_config", return_value=conf)
+    app, web_dir = compilable_app
+
+    app.add_page(rx.box("Index"), route="/")
+    app._compile()
+
+    components_js = (
+        web_dir
+        / constants.Dirs.UTILS
+        / f"{constants.PageNames.COMPONENTS}{constants.Ext.JSX}"
+    ).read_text()
+
+    assert "export const DefaultOverlayComponents" in components_js
+    assert "export const MemoizedToastProvider" in components_js
+
+
 @pytest.mark.parametrize(
     "react_strict_mode",
     [True, False],