TagListのConverterを実装した

source/src/main/java/one/nem/lacerta/source/database/common/TagListConverter.java

@@ -0,0 +1,19 @@
+package one.nem.lacerta.source.database.common;
+
+import androidx.room.TypeConverter;
+
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+
+public class TagListConverter {
+    @TypeConverter
+    public static String fromList(List<String> list) {
+        return list == null ? null : String.join(",", list);
+    }
+
+    @TypeConverter
+    public static List<String> fromString(String value) {
+        return value == null ? Collections.emptyList() : Arrays.asList(value.split(","));
+    }
+}