From 9ec7c1227621d2260be0e4c94ce2605ce21f0890 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Javier=20Ch=C3=A1varri?= <javier.chavarri@gmail.com>
Date: Tue, 4 Jun 2024 04:09:22 +0200
Subject: [PATCH] test: memo and renders (#825)

---
 test/React__test.re | 50 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 50 insertions(+)

diff --git a/test/React__test.re b/test/React__test.re
index b96e9da61..bfa76985e 100644
--- a/test/React__test.re
+++ b/test/React__test.re
@@ -359,4 +359,54 @@ describe("React", () => {
     /* We catch the exception here to not populate the error to the toplevel */
     ()
   };
+
+  test(
+    "Memo and normal components rendering with equal and different props", () => {
+    let container = getContainer(container);
+    let root = ReactDOM.Client.createRoot(container);
+
+    module Normal = {
+      let renders = ref(0);
+
+      [@react.component]
+      let make = (~a) => {
+        renders := renders^ + 1;
+        <div> {Printf.sprintf("`a` is %s", a) |> React.string} </div>;
+      };
+    };
+
+    module Memo = {
+      let renders = ref(0);
+
+      [@react.component]
+      let make =
+        React.memo((~a) => {
+          renders := renders^ + 1;
+          <div> {Printf.sprintf("`a` is %s", a) |> React.string} </div>;
+        });
+    };
+
+    act(() => {
+      ReactDOM.Client.render(
+        root,
+        <div> <Normal a="a" /> <Memo a="a" /> </div>,
+      )
+    });
+    act(() => {
+      ReactDOM.Client.render(
+        root,
+        <div> <Normal a="a" /> <Memo a="a" /> </div>,
+      )
+    });
+    act(() => {
+      ReactDOM.Client.render(
+        root,
+        <div> <Normal a="b" /> <Memo a="b" /> </div>,
+      )
+    });
+
+    expect(Normal.renders^)->toBe(3);
+
+    expect(Memo.renders^)->toBe(2);
+  });
 });