From 91c3dd9aecc362c994954c0afdebacd197812309 Mon Sep 17 00:00:00 2001
From: Daniel Cachapa <cachapa@gmail.com>
Date: Sat, 16 Sep 2023 16:34:51 +0200
Subject: [PATCH] Add `isDeleted` flag to watched change events

---
 CHANGELOG.md                        |  4 ++++
 lib/src/map_crdt/map_crdt.dart      | 10 ++++++----
 lib/src/map_crdt/map_crdt_base.dart |  4 +++-
 pubspec.yaml                        |  2 +-
 test/map_crdt_test.dart             | 10 +++++++++-
 5 files changed, 23 insertions(+), 7 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9937ab6..f6a7898 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 5.1.2
+
+- Add `isDeleted` flag to watched change events
+
 ## 5.1.1
 
 - Remove timezone drift from `Hlc.toString`
diff --git a/lib/src/map_crdt/map_crdt.dart b/lib/src/map_crdt/map_crdt.dart
index 78d6770..8921318 100644
--- a/lib/src/map_crdt/map_crdt.dart
+++ b/lib/src/map_crdt/map_crdt.dart
@@ -8,7 +8,8 @@ import 'record.dart';
 /// datasets. It is incredibly inefficient.
 class MapCrdt extends MapCrdtBase {
   final Map<String, Map<String, Record>> _recordMaps;
-  final Map<String, StreamController<({String key, dynamic value})>>
+  final Map<String,
+          StreamController<({String key, dynamic value, bool isDeleted})>>
       _changeControllers;
 
   @override
@@ -37,13 +38,14 @@ class MapCrdt extends MapCrdtBase {
   void putRecords(Map<String, Map<String, Record>> dataset) {
     dataset.forEach((table, records) {
       _recordMaps[table]!.addAll(records);
-      records.forEach((key, value) =>
-          _changeControllers[table]!.add((key: key, value: value.value)));
+      records.forEach((key, record) => _changeControllers[table]!
+          .add((key: key, value: record.value, isDeleted: record.isDeleted)));
     });
   }
 
   @override
-  Stream<({String key, dynamic value})> watch(String table, {String? key}) {
+  Stream<({String key, dynamic value, bool isDeleted})> watch(String table,
+      {String? key}) {
     if (!tables.contains(table)) throw 'Unknown table: $table';
     return key == null
         ? _changeControllers[table]!.stream
diff --git a/lib/src/map_crdt/map_crdt_base.dart b/lib/src/map_crdt/map_crdt_base.dart
index 1af4eb0..6486a56 100644
--- a/lib/src/map_crdt/map_crdt_base.dart
+++ b/lib/src/map_crdt/map_crdt_base.dart
@@ -7,6 +7,8 @@ import '../hlc.dart';
 import '../types.dart';
 import 'record.dart';
 
+typedef WatchEvent = ({String key, dynamic value, bool isDeleted});
+
 /// A CRDT backed by a simple in-memory hashmap.
 /// Useful for testing, or for applications which only require small, ephemeral
 /// datasets. It is incredibly inefficient.
@@ -97,7 +99,7 @@ abstract class MapCrdtBase extends Crdt {
   /// Returns a stream of changes.
   /// Use the optional [key] parameter to filter events or leave it empty to get
   /// all changes.
-  Stream<({String key, dynamic value})> watch(String table, {String? key});
+  Stream<WatchEvent> watch(String table, {String? key});
 
   @override
   CrdtChangeset getChangeset({
diff --git a/pubspec.yaml b/pubspec.yaml
index fdd1597..9f8ad9f 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,6 +1,6 @@
 name: crdt
 description: Dart implementation of Conflict-free Replicated Data Types (CRDTs).
-version: 5.1.1
+version: 5.1.2
 homepage: https://github.com/cachapa/crdt
 repository: https://github.com/cachapa/crdt
 issue_tracker: https://github.com/cachapa/crdt/issues
diff --git a/test/map_crdt_test.dart b/test/map_crdt_test.dart
index b921ce3..cc412ff 100644
--- a/test/map_crdt_test.dart
+++ b/test/map_crdt_test.dart
@@ -364,10 +364,18 @@ void main() {
 
     test('Single change', () async {
       // ignore: unawaited_futures
-      expectLater(crdt.watch('table'), emits((key: 'x', value: 1)));
+      expectLater(
+          crdt.watch('table'), emits((key: 'x', value: 1, isDeleted: false)));
       await crdt.put('table', 'x', 1);
     });
 
+    test('Deleted', () async {
+      // ignore: unawaited_futures
+      expectLater(
+          crdt.watch('table'), emits((key: 'x', value: 1, isDeleted: true)));
+      await crdt.put('table', 'x', 1, true);
+    });
+
     test('Enforce table existence', () {
       expect(
         () => crdt.watch('not_table'),