Encode ScanArgs.matches using UTF-8 #792

Lettuce now uses UTF-8 encoding to encode the matches string to bytes. Previously, we used ASCII which is more limiting when using non-ascii chars.

src/main/java/com/lambdaworks/redis/ScanArgs.java

@@ -18,6 +18,8 @@
 import static com.lambdaworks.redis.protocol.CommandKeyword.COUNT;
 import static com.lambdaworks.redis.protocol.CommandKeyword.MATCH;
 
+import java.nio.charset.StandardCharsets;
+
 import com.lambdaworks.redis.internal.LettuceAssert;
 import com.lambdaworks.redis.protocol.CommandArgs;
 
@@ -99,7 +101,7 @@ public ScanArgs limit(long count) {
     <K, V> void build(CommandArgs<K, V> args) {
 
         if (match != null) {
-            args.add(MATCH).add(match);
+            args.add(MATCH).add(match.getBytes(StandardCharsets.UTF_8));
         }
 
         if (count != null) {

src/test/java/com/lambdaworks/redis/ScanArgsTest.java

@@ -0,0 +1,53 @@
+/*
+ * Copyright 2018 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.lambdaworks.redis;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import org.junit.Test;
+
+import com.lambdaworks.redis.codec.StringCodec;
+import com.lambdaworks.redis.protocol.CommandArgs;
+
+import io.netty.buffer.ByteBuf;
+import io.netty.buffer.Unpooled;
+
+/**
+ * @author Mark Paluch
+ */
+public class ScanArgsTest {
+
+    @Test
+    public void shouldEncodeMatchUsingUtf8() {
+
+        ScanArgs args = ScanArgs.Builder.matches("ö");
+
+        CommandArgs<String, String> commandArgs = new CommandArgs<>(StringCodec.UTF8);
+        args.build(commandArgs);
+
+        ByteBuf buffer = Unpooled.buffer();
+        commandArgs.encode(buffer);
+
+        ByteBuf expected = Unpooled.buffer();
+        expected.writeBytes("$5\r\nMATCH\r\n".getBytes());
+        expected.writeBytes("$2\r\n".getBytes());
+        expected.writeByte(-61); // encoded ö
+        expected.writeByte(-74);
+        expected.writeBytes("\r\n".getBytes());
+
+        assertThat(buffer).isEqualTo(expected);
+    }
+}