implement msetnx (#299)

* implement msetnx
* fix mget

Author: inponomarev

src/main/java/com/github/fppt/jedismock/operations/strings/MGet.java

@@ -1,5 +1,6 @@
 package com.github.fppt.jedismock.operations.strings;
 
+import com.github.fppt.jedismock.datastructures.RMString;
 import com.github.fppt.jedismock.operations.AbstractRedisOperation;
 import com.github.fppt.jedismock.operations.RedisCommand;
 import com.github.fppt.jedismock.server.Response;
@@ -17,8 +18,10 @@ class MGet extends AbstractRedisOperation {
     }
 
     protected Slice response() {
+        RedisBase base = base();
         return Response.array(params().stream()
-                .map(key-> base().getRMString(key) != null ? (base().getRMString(key).getAsSlice()) : null)
+                .map(base::getValue)
+                .map(s -> s instanceof RMString ? (s.getAsSlice()) : null)
                 .map(Response::bulkString)
                 .collect(toList()));
     }

src/main/java/com/github/fppt/jedismock/operations/strings/MSetNX.java

@@ -0,0 +1,30 @@
+package com.github.fppt.jedismock.operations.strings;
+
+import com.github.fppt.jedismock.datastructures.Slice;
+import com.github.fppt.jedismock.operations.AbstractRedisOperation;
+import com.github.fppt.jedismock.operations.RedisCommand;
+import com.github.fppt.jedismock.server.Response;
+import com.github.fppt.jedismock.storage.RedisBase;
+
+import java.util.List;
+
+@RedisCommand("msetnx")
+public class MSetNX extends AbstractRedisOperation {
+    public MSetNX(RedisBase base, List<Slice> params) {
+        super(base, params);
+    }
+
+    @Override
+    protected Slice response() {
+        RedisBase base = base();
+        for (int i = 0; i < params().size(); i += 2) {
+            if (base.exists(params().get(i))) {
+                return Response.integer(0);
+            }
+        }
+        for (int i = 0; i < params().size(); i += 2) {
+            base.putValue(params().get(i), params().get(i + 1).extract());
+        }
+        return Response.integer(1);
+    }
+}

src/test/java/com/github/fppt/jedismock/comparisontests/strings/TestMGet.java

@@ -0,0 +1,34 @@
+package com.github.fppt.jedismock.comparisontests.strings;
+
+import com.github.fppt.jedismock.comparisontests.ComparisonBase;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.TestTemplate;
+import org.junit.jupiter.api.extension.ExtendWith;
+import redis.clients.jedis.Jedis;
+
+import java.util.Arrays;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+@ExtendWith(ComparisonBase.class)
+public class TestMGet {
+    @BeforeEach
+    public void setUp(Jedis jedis) {
+        jedis.flushAll();
+    }
+
+    @TestTemplate
+    public void mget(Jedis jedis) {
+        jedis.set("key1", "Hello");
+        jedis.set("key2", "World");
+        assertEquals(Arrays.asList("Hello", "World", null), jedis.mget("key1", "key2", "key3"));
+    }
+
+
+    @TestTemplate
+    public void mgetWithNonText(Jedis jedis) {
+        jedis.set("key1", "Hello");
+        jedis.hset("key2", "field", "World");
+        assertEquals(Arrays.asList("Hello", null), jedis.mget("key1", "key2"));
+    }
+}

src/test/java/com/github/fppt/jedismock/comparisontests/strings/TestMSetNX.java

@@ -0,0 +1,26 @@
+package com.github.fppt.jedismock.comparisontests.strings;
+
+import com.github.fppt.jedismock.comparisontests.ComparisonBase;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.TestTemplate;
+import org.junit.jupiter.api.extension.ExtendWith;
+import redis.clients.jedis.Jedis;
+
+import java.util.Arrays;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+@ExtendWith(ComparisonBase.class)
+public class TestMSetNX {
+    @BeforeEach
+    public void setUp(Jedis jedis) {
+        jedis.flushAll();
+    }
+
+    @TestTemplate
+    public void msetnx(Jedis jedis) {
+        assertEquals(1, jedis.msetnx("key1", "Hello", "key2", "there"));
+        assertEquals(0, jedis.msetnx("key2", "new", "key3", "world"));
+        assertEquals(Arrays.asList("Hello", "there", null), jedis.mget("key1", "key2", "key3"));
+    }
+}