feat(redis_client): add increment and incrementBy (#3014)

packages/redis_client/lib/src/redis_client.dart

@@ -1,3 +1,4 @@
+// cspell:words INCRBYFLOAT
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
@@ -200,6 +201,23 @@ class RedisClient {
   /// https://redis.io/commands/unlink
   Future<void> unlink({required String key}) => execute(['UNLINK', key]);
 
+  /// Increment the floating point number stored at key by one.
+  /// Returns the newly incremented value.
+  /// Equivalent to the `INCR` command.
+  /// https://redis.io/commands/incr
+  Future<num> increment({required String key}) async {
+    return await execute(['INCR', key]) as num;
+  }
+
+  /// Increment the floating point number stored at key by the specified value.
+  /// Returns the newly incremented value.
+  /// Equivalent to the `INCRBYFLOAT` command.
+  /// https://redis.io/commands/incrbyfloat
+  Future<num> incrementBy({required String key, required num value}) async {
+    final result = await execute(['INCRBYFLOAT', key, value]) as String;
+    return num.parse(result);
+  }
+
   /// Send a command to the Redis server.
   Future<dynamic> execute(List<Object?> command) async {
     return _runWithRetry(() async {

packages/redis_client/test/src/redis_client_test.dart

@@ -1,3 +1,4 @@
+// cspell:words INCRBYFLOAT
 import 'dart:async';
 import 'dart:io';
 
@@ -221,6 +222,37 @@ void main() {
       });
     });
 
+    group('INCR/INCRBYFLOAT', () {
+      setUp(() async {
+        await client.connect();
+      });
+
+      tearDown(() async {
+        try {
+          await client.execute(['RESET']);
+          await client.execute(['FLUSHALL']);
+        } on Exception {
+          // ignore
+        }
+      });
+
+      test('completes', () async {
+        const key = 'key';
+        const value = '10';
+        await expectLater(client.increment(key: key), completion(equals(1)));
+        await expectLater(client.set(key: key, value: value), completes);
+        await expectLater(
+          client.incrementBy(key: key, value: 42.2),
+          completion(equals(52.2)),
+        );
+        await expectLater(
+          client.incrementBy(key: key, value: -52.2),
+          completion(equals(0.0)),
+        );
+        await expectLater(client.delete(key: key), completes);
+      });
+    });
+
     group('JSON', () {
       group('GET/SET/DEL/MERGE', () {
         setUp(() async {