🔀 Add support for element fragments. (#99)

* #16 add fragment POC

* WIP

* 16 add fragment support to morph

* add keys for fragments

* ensure proper fragment order, refactor to handle fragment/element more similarly

* fix comment typo, incorrect child typo, simplify key check

* fix comment typo

* add snapshot tests

* flatten fragment using fold right, appending elements

* doc update

---------

Co-authored-by: Hayleigh Thompson <me@hayleigh.dev>

1 files changed, 45 insertions, 0 deletions

diff --git a/test/apps/fragment.gleam b/test/apps/fragment.gleam
new file mode 100644
index 0000000..d20400e
--- /dev/null
+++ b/test/apps/fragment.gleam
@@ -0,0 +1,45 @@
+// Similar to count app, with fragments and edge cases
+
+// IMPORTS ---------------------------------------------------------------------
+
+import gleam/int
+import lustre/element.{text}
+import lustre/element/html.{button, p}
+import lustre/event
+
+// MODEL -----------------------------------------------------------------------
+
+pub type Model =
+  Int
+
+pub fn init(count) {
+  count
+}
+
+// UPDATE ----------------------------------------------------------------------
+
+pub type Msg {
+  Increment
+  Decrement
+}
+
+pub fn update(model, msg) {
+  case msg {
+    Increment -> model + 1
+    Decrement -> model - 1
+  }
+}
+
+// VIEW ------------------------------------------------------------------------
+
+pub fn view(model) {
+  let count = int.to_string(model)
+  element.fragment([
+    element.fragment([p([], [element.text("start fragment")])]),
+    element.fragment([p([], [element.text("middle fragment")])]),
+    element.fragment([p([], [element.text(count)])]),
+    button([event.on_click(Decrement)], [text("-")]),
+    button([event.on_click(Increment)], [text("+")]),
+    p([], [element.text("order check, last element")]),
+  ])
+}