🔀 Fix a bug where nested `Map` nodes were not morphed. (#115)

* ensure nested subtrees are morphed

* Add a test-app for nested element map bug

1 files changed, 51 insertions, 0 deletions

diff --git a/test-apps/nested-element-map/src/app.gleam b/test-apps/nested-element-map/src/app.gleam
new file mode 100644
index 0000000..ed91763
--- /dev/null
+++ b/test-apps/nested-element-map/src/app.gleam
@@ -0,0 +1,51 @@
+import lustre
+import lustre/element.{type Element, element}
+import lustre/element/html
+import lustre/event
+
+// MAIN ------------------------------------------------------------------------
+
+pub fn main() {
+  let app = lustre.simple(init, update, view)
+  let assert Ok(_) = lustre.start(app, "#app", Nil)
+}
+
+// MODEL -----------------------------------------------------------------------
+
+type Model =
+  String
+
+fn init(_flags) -> Model {
+  "div"
+}
+
+// UPDATE ----------------------------------------------------------------------
+pub opaque type Baby {
+  Waaa
+}
+
+pub opaque type Child {
+  BabyMsg(Baby)
+}
+
+pub opaque type Msg {
+  ChildMsg(Child)
+}
+
+fn update(model: Model, _msg: Msg) -> Model {
+  model
+}
+
+// VIEW ------------------------------------------------------------------------
+
+fn view(_model: Model) -> Element(Msg) {
+  html.div([], [
+    html.text("parent"),
+    html.div([], [
+      html.text("child"),
+      html.div([event.on_click(Waaa)], [html.text("baby")])
+        |> element.map(BabyMsg),
+    ])
+      |> element.map(ChildMsg),
+  ])
+}