Re-add MaterialConverter class and add tests

src/main/java/org/mvplugins/multiverse/core/utils/MaterialConverter.java

@@ -0,0 +1,27 @@
+package org.mvplugins.multiverse.core.utils;
+
+import de.themoep.idconverter.IdMappings;
+import org.bukkit.Material;
+import org.jetbrains.annotations.Nullable;
+
+/**
+ * A tool for converting values which may be an old type ID to a Material.
+ */
+public class MaterialConverter {
+
+    /**
+     * Converts a string representing a numeric id or flattened material name to a Material.
+     *
+     * @param value The value to convert.
+     * @return The converted Material type or null if no matching type.
+     */
+    @Nullable
+    public static Material stringToMaterial(@Nullable String value) {
+        IdMappings.Mapping mapping = IdMappings.getById(value != null ? value : "");
+        if (mapping != null) {
+            return Material.matchMaterial(mapping.getFlatteningType());
+        } else {
+            return Material.matchMaterial(value != null ? value : "");
+        }
+    }
+}

src/main/java/org/mvplugins/multiverse/core/world/config/CurrencySerializer.java

@@ -1,11 +1,10 @@
 package org.mvplugins.multiverse.core.world.config;
 
-import de.themoep.idconverter.IdMappings;
 import io.vavr.control.Option;
 import org.bukkit.Material;
-import org.jetbrains.annotations.Nullable;
 import org.mvplugins.multiverse.core.configuration.functions.NodeSerializer;
 import org.mvplugins.multiverse.core.economy.MVEconomist;
+import org.mvplugins.multiverse.core.utils.MaterialConverter;
 
 /**
  * Converts the material name to/from a {@link Material} enum, with the special case of "vault-economy"
@@ -26,27 +25,11 @@ public Material deserialize(Object object, Class<Material> type) {
                     if (materialStr.equalsIgnoreCase(VAULT_ECONOMY_CODE)) {
                         return MVEconomist.VAULT_ECONOMY_MATERIAL;
                     }
-                    return stringToMaterial(materialStr);
+                    return MaterialConverter.stringToMaterial(materialStr);
                 })
                 .getOrElse(MVEconomist.VAULT_ECONOMY_MATERIAL);
     }
 
-    /**
-     * Converts a string representing a numeric id or flattened material name to a Material.
-     *
-     * @param value The value to convert.
-     * @return The converted Material type or null if no matching type.
-     */
-    @Nullable
-    private Material stringToMaterial(@Nullable String value) {
-        IdMappings.Mapping mapping = IdMappings.getById(value != null ? value : "");
-        if (mapping != null) {
-            return Material.matchMaterial(mapping.getFlatteningType());
-        } else {
-            return Material.matchMaterial(value != null ? value : "");
-        }
-    }
-
     /**
      * {@inheritDoc}
      */

src/test/java/org/mvplugins/multiverse/core/utils/MaterialConverterTest.kt

@@ -0,0 +1,29 @@
+package org.mvplugins.multiverse.core.utils
+
+import org.bukkit.Material
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertNull
+
+class MaterialConverterTest {
+
+    @Test
+    fun `Convert dirt name to material`() {
+        assertEquals(Material.DIRT, MaterialConverter.stringToMaterial("dirt"))
+    }
+
+    @Test
+    fun `Convert Spruce Planks numerical id to material`() {
+        assertEquals(Material.SPRUCE_PLANKS, MaterialConverter.stringToMaterial("5:1"))
+    }
+
+    @Test
+    fun `Convert Oak Sapling item id to material`() {
+        assertEquals(Material.OAK_SAPLING, MaterialConverter.stringToMaterial("minecraft:oak_sapling"))
+    }
+
+    @Test
+    fun `Convert invalid string to material`() {
+        assertNull(MaterialConverter.stringToMaterial("invalid"))
+    }
+}