From a40af023bf615a9c54e4007c9bb00c2632e1f4d4 Mon Sep 17 00:00:00 2001
From: Andrew Meyer <andrew.meyer@mongodb.com>
Date: Fri, 1 Sep 2023 13:43:08 +0200
Subject: [PATCH] Make useObject compatible with undefined objects

* If somehow an object returns undefined, re-renders would be skipped
* Added tests for proving that re-renders occur when the database is cleared
* Removed 11.0.0-rc from peer-dependency
---
 packages/realm-react/package.json             |  4 ++--
 .../src/__tests__/useObjectRender.test.tsx    | 18 ++++++++++++++++++
 .../src/__tests__/useQueryRender.test.tsx     | 19 +++++++++++++++++++
 packages/realm-react/src/useObject.tsx        |  6 +++---
 4 files changed, 42 insertions(+), 5 deletions(-)

diff --git a/packages/realm-react/package.json b/packages/realm-react/package.json
index 93a6d68527..baf224c639 100644
--- a/packages/realm-react/package.json
+++ b/packages/realm-react/package.json
@@ -70,13 +70,13 @@
     "react": "18.2.0",
     "react-native": "0.71.7",
     "react-test-renderer": "18.2.0",
-    "realm": "*",
+    "realm": "^11.0.0-rc.0",
     "rollup-plugin-dts": "^5.0.0",
     "ts-jest": "^29.0.5"
   },
   "peerDependencies": {
     "react": ">=17.0.2",
-    "realm": "^12.0.0-browser || ^12.0.0 || ^12.0.0-rc || ^11.0.0-rc || ^11.0.0"
+    "realm": "^12.0.0-browser || ^12.0.0 || ^12.0.0-rc || ^11.0.0"
   },
   "optionalDependencies": {
     "@babel/runtime": ">=7",
diff --git a/packages/realm-react/src/__tests__/useObjectRender.test.tsx b/packages/realm-react/src/__tests__/useObjectRender.test.tsx
index fc138fcc07..d17230eb0b 100644
--- a/packages/realm-react/src/__tests__/useObjectRender.test.tsx
+++ b/packages/realm-react/src/__tests__/useObjectRender.test.tsx
@@ -438,6 +438,24 @@ describe("useObject: rendering objects with a Realm.List property", () => {
       fireEvent.press(rerenderButton);
       expect(objectChangeCounter).toHaveBeenCalledTimes(expectedCount);
     });
+    it("will rerender when the realm database is cleared", async () => {
+      await setupTest();
+
+      const initialCount = 2;
+
+      expect(objectChangeCounter).toHaveBeenCalledTimes(initialCount);
+
+      await act(async () => {
+        testRealm.write(() => {
+          testRealm.deleteAll();
+        });
+        forceSynchronousNotifications(testRealm);
+      });
+
+      await new Promise((resolve) => setTimeout(resolve, 1000));
+
+      expect(objectChangeCounter).toHaveBeenCalledTimes(initialCount + 1);
+    });
   });
 
   describe("rendering objects with a Realm.List property", () => {
diff --git a/packages/realm-react/src/__tests__/useQueryRender.test.tsx b/packages/realm-react/src/__tests__/useQueryRender.test.tsx
index 9b391b27d0..839ab8d349 100644
--- a/packages/realm-react/src/__tests__/useQueryRender.test.tsx
+++ b/packages/realm-react/src/__tests__/useQueryRender.test.tsx
@@ -443,4 +443,23 @@ describe.each`
     fireEvent.press(rerenderButton);
     expect(queryObjectChangeCounter).toHaveBeenCalledTimes(1);
   });
+
+  it("will rerender when the realm database is cleared", async () => {
+    await setupTest({ queryType });
+
+    const initialCount = 1;
+
+    expect(queryObjectChangeCounter).toHaveBeenCalledTimes(initialCount);
+
+    await act(async () => {
+      testRealm.write(() => {
+        testRealm.deleteAll();
+      });
+      forceSynchronousNotifications(testRealm);
+    });
+
+    await new Promise((resolve) => setTimeout(resolve, 1000));
+
+    expect(queryObjectChangeCounter).toHaveBeenCalledTimes(initialCount + 1);
+  });
 });
diff --git a/packages/realm-react/src/useObject.tsx b/packages/realm-react/src/useObject.tsx
index 985de52352..c9e89b5021 100644
--- a/packages/realm-react/src/useObject.tsx
+++ b/packages/realm-react/src/useObject.tsx
@@ -56,7 +56,7 @@ export function createUseObject(useRealm: () => Realm) {
     // Ref: https://github.com/facebook/react/issues/14490
     const cachedObjectRef = useRef<null | CachedObject>(null);
 
-    if (cachedObjectRef.current === null) {
+    if (!cachedObjectRef.current) {
       cachedObjectRef.current = createCachedObject({
         object: originalObject ?? null,
         realm,
@@ -81,7 +81,7 @@ export function createUseObject(useRealm: () => Realm) {
         // Re-instantiate the cachedObject if the primaryKey has changed or the originalObject has gone from null to not null
         if (
           !arePrimaryKeysIdentical(primaryKey, primaryKeyRef.current) ||
-          (originalObjectRef.current === null && originalObject !== null)
+          (!originalObjectRef.current && originalObject)
         ) {
           cachedObjectRef.current = createCachedObject({
             object: originalObject ?? null,
@@ -138,7 +138,7 @@ export function createUseObject(useRealm: () => Realm) {
     }, [realm, type, forceRerender]);
 
     // If the object has been deleted or doesn't exist for the given primary key, just return null
-    if (object === null || object?.isValid() === false) {
+    if (!object || object?.isValid() === false) {
       return null;
     }