From f2160b8259053b7db5002ba21fd5805a58432649 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kasper=20Overg=C3=A5rd=20Nielsen?= <kasper@byolimit.com>
Date: Fri, 9 Sep 2022 17:45:26 +0200
Subject: [PATCH 1/4] Add realm specific implementation for List.add and
 List.insert

---
 lib/src/list.dart | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/lib/src/list.dart b/lib/src/list.dart
index 7f531e56b..e53a70a3c 100644
--- a/lib/src/list.dart
+++ b/lib/src/list.dart
@@ -63,7 +63,11 @@ class ManagedRealmList<T extends Object?> extends collection.ListBase<T> with Re
   @override
   set length(int newLength) {
     var l = length;
-    if (newLength < l) removeRange(newLength, l);
+    if (newLength < l) {
+      removeRange(newLength, l);
+    } else {
+      throw RealmException('You cannot increase length on a realm list without adding elements');
+    }
   }
 
   @override
@@ -93,6 +97,16 @@ class ManagedRealmList<T extends Object?> extends collection.ListBase<T> with Re
     }
   }
 
+  @override
+  void add(T element) {
+    RealmListInternal.setValue(handle, realm, length, element);
+  }
+
+  @override
+  void insert(int index, T element) {
+    realmCore.listInsertElementAt(handle, index, element);
+  }
+
   @override
   void operator []=(int index, T value) {
     RealmListInternal.setValue(handle, realm, index, value);

From 014b32e91c665c8de3001a664277ebd175e03337 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kasper=20Overg=C3=A5rd=20Nielsen?= <kasper@byolimit.com>
Date: Fri, 9 Sep 2022 17:58:01 +0200
Subject: [PATCH 2/4] Add test case

---
 test/list_test.dart | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/test/list_test.dart b/test/list_test.dart
index fb02ab7ee..ad298050d 100644
--- a/test/list_test.dart
+++ b/test/list_test.dart
@@ -699,4 +699,15 @@ Future<void> main([List<String>? args]) async {
     expect(team.players, isNot(players));
     expect(team.players, unorderedMatches(players));
   });
+
+  test('ManagedRealmList.length= throws', () {
+    final config = Configuration.local([Team.schema, Person.schema]);
+    final realm = getRealm(config);
+
+    final team = Team('sad team');
+
+    realm.write(() => realm.add(team));
+
+    expect(() => realm.write(() => team.players.length = 100), throws<RealmException>('You cannot increase length on a realm list without adding elements'));
+  });
 }

From 1221f77c982d1fc7df2a4953cd0c811d9d270bdb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kasper=20Overg=C3=A5rd=20Nielsen?= <kasper@byolimit.com>
Date: Fri, 9 Sep 2022 18:01:36 +0200
Subject: [PATCH 3/4] Update CHANGELOG

---
 CHANGELOG.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6071e241b..e2fdabcea 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,7 @@
 ### Fixed
 * Allow null arguments on query. ([#872](https://github.com/realm/realm-dart/pull/872)). Fixes [#871](https://github.com/realm/realm-dart/issues/871)
 * Previously removeAt did not truncate length. ([#884](https://github.com/realm/realm-dart/pull/884)). Fixes [#883](https://github.com/realm/realm-dart/issues/883)
+* List.length= now throws, if you try to increase length, ([#894](https://github.com/realm/realm-dart/pull/894)).
 
 ### Compatibility
 * Realm Studio: 12.0.0 or later.

From e5940ca0850c7e19ef61c8821fccaa73c5c2ccc5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kasper=20Overg=C3=A5rd=20Nielsen?= <kasper@byolimit.com>
Date: Mon, 12 Sep 2022 11:49:12 +0200
Subject: [PATCH 4/4] Add test case for decreasing lenght

---
 test/list_test.dart | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/test/list_test.dart b/test/list_test.dart
index ad298050d..25e561f8d 100644
--- a/test/list_test.dart
+++ b/test/list_test.dart
@@ -700,7 +700,7 @@ Future<void> main([List<String>? args]) async {
     expect(team.players, unorderedMatches(players));
   });
 
-  test('ManagedRealmList.length= throws', () {
+  test('ManagedRealmList.length= throws on increase', () {
     final config = Configuration.local([Team.schema, Person.schema]);
     final realm = getRealm(config);
 
@@ -710,4 +710,18 @@ Future<void> main([List<String>? args]) async {
 
     expect(() => realm.write(() => team.players.length = 100), throws<RealmException>('You cannot increase length on a realm list without adding elements'));
   });
+
+  test('ManagedRealmList.length= truncates on decrease', () {
+    final config = Configuration.local([Team.schema, Person.schema]);
+    final realm = getRealm(config);
+
+    final team = Team('sad team', players: [for (int i = 0; i < 100; ++i) Person('$i')]);
+    realm.write(() => realm.add(team));
+    expect(team.players.length, 100);
+    expect(realm.all<Person>().length, 100);
+
+    expect(realm.write(() => team.players.length = 10), 10);
+    expect(team.players.length, 10);
+    expect(realm.all<Person>().length, 100);
+  });
 }