add unit test for MPVCommand

src/test/java/com/mykola2312/mptv/TestMPVCommand.java

@@ -0,0 +1,48 @@
+package com.mykola2312.mptv;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+import java.nio.charset.StandardCharsets;
+import java.util.Arrays;
+import java.util.List;
+
+import org.junit.jupiter.api.Test;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.mykola2312.mptv.mpv.MPVCommand;
+import com.mykola2312.mptv.mpv.MPVCommandResult;
+
+public class TestMPVCommand {
+    private class TestCommand extends MPVCommand {
+        @Override
+        protected List<String> serializeCommand() {
+            return Arrays.asList("name", "arg1", "arg2");
+        }
+
+    }
+
+    private static final byte[] EXPECTED_BUF =
+        "{\"request_id\":0,\"command\":[\"name\",\"arg1\",\"arg2\"]}\n"
+        .getBytes(StandardCharsets.UTF_8);
+
+    @Test()
+    public void testSerialize() throws JsonProcessingException {
+        TestCommand testCommand = new TestCommand();
+
+        assertDoesNotThrow(() -> testCommand.serialize());
+        assertArrayEquals(EXPECTED_BUF, testCommand.serialize());
+    }
+
+    private static final String RESULT_LINE = "{\"data\":5.440000,\"request_id\":0,\"error\":\"success\"}\n";
+
+    @Test()
+    public void testDeserializeResult() throws JsonProcessingException {
+        assertDoesNotThrow(() -> MPVCommandResult.deserialize(RESULT_LINE));
+        MPVCommandResult result = MPVCommandResult.deserialize(RESULT_LINE);
+
+        assertNotNull(result);
+        assertNotNull(result.request_id);
+        assertNotNull(result.error);
+        assertEquals("5.440000", result.data);
+    }
+}