Attempts to clean the migration code a bit

src/main/java/net/knarcraft/knarlib/config/StargateYamlConfiguration.java

@@ -65,13 +65,13 @@ public class StargateYamlConfiguration extends YamlConfiguration {
      * Loads the configuration of the given plugin
      *
      * @param plugin       <p>The plugin to load the configuration from</p>
+     * @param copyDefaults <p>Whether to copy default values when loading</p>
      * @return <p>The loaded configuration, or null if unsuccessful</p>
      */
-    @SuppressWarnings("unused")
     @Nullable
-    public static StargateYamlConfiguration loadConfiguration(@NotNull Plugin plugin) {
+    public static StargateYamlConfiguration loadConfiguration(@NotNull Plugin plugin, boolean copyDefaults) {
         StargateYamlConfiguration configuration = new StargateYamlConfiguration();
-        configuration.options().copyDefaults(true);
+        configuration.options().copyDefaults(copyDefaults);
         try {
             configuration.load(new File(plugin.getDataFolder(), ConfigHelper.getConfigFile()));
             return configuration;
@@ -88,7 +88,6 @@ public class StargateYamlConfiguration extends YamlConfiguration {
      * @param configuration <p>The configuration to save</p>
      * @return <p>True if the configuration was successfully saved</p>
      */
-    @SuppressWarnings("unused")
     public static boolean saveConfiguration(@NotNull Plugin plugin, @NotNull FileConfiguration configuration) {
         try {
             configuration.save(new File(plugin.getDataFolder(), ConfigHelper.getConfigFile()));

src/main/java/net/knarcraft/knarlib/util/ConfigHelper.java

@@ -3,12 +3,12 @@ package net.knarcraft.knarlib.util;
 import net.knarcraft.knarlib.config.StargateYamlConfiguration;
 import net.knarcraft.knarlib.property.ColorConversion;
 import org.bukkit.configuration.ConfigurationSection;
-import org.bukkit.configuration.InvalidConfigurationException;
 import org.bukkit.configuration.MemorySection;
 import org.bukkit.configuration.file.FileConfiguration;
 import org.bukkit.configuration.file.YamlConfiguration;
 import org.bukkit.plugin.Plugin;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 import java.io.File;
 import java.io.IOException;
@@ -65,31 +65,22 @@ public final class ConfigHelper {
         File dataFolder = plugin.getDataFolder();
         File config = new File(dataFolder, CONFIG_FILE);
 
+        // Load the old configuration as a normal configuration to prevent old comments from being retained
+        FileConfiguration oldConfiguration = StargateYamlConfiguration.loadConfiguration(plugin, false);
+        if (oldConfiguration == null) {
+            return false;
+        }
+
         //Save the old config just in case something goes wrong
         try {
-            StargateYamlConfiguration currentConfiguration = new StargateYamlConfiguration();
+            oldConfiguration.save(new File(dataFolder, BACKUP_CONFIG_FILE));
-            currentConfiguration.load(config);
+        } catch (IOException exception) {
-            currentConfiguration.save(new File(dataFolder, BACKUP_CONFIG_FILE));
-        } catch (IOException | InvalidConfigurationException exception) {
             plugin.getLogger().log(Level.WARNING, "Unable to save old backup and do migration");
             return false;
         }
 
-        //Load old and new configuration
+        InputStream configStream = loadInternalFile(plugin, CONFIG_FILE, "internal configuration");
-        plugin.reloadConfig();
-        FileConfiguration oldConfiguration;
-        try {
-            oldConfiguration = new YamlConfiguration();
-            oldConfiguration.load(config);
-        } catch (IOException | InvalidConfigurationException exception) {
-            plugin.getLogger().log(Level.WARNING, "Unable to load old configuration and do migration");
-            return false;
-        }
-        
-        InputStream configStream = FileHelper.getInputStreamForInternalFile("/" + CONFIG_FILE);
         if (configStream == null) {
-            plugin.getLogger().log(Level.SEVERE, "Could not migrate the configuration, as the internal " +
-                    "configuration could not be read!");
             return false;
         }
         YamlConfiguration newConfiguration = StargateYamlConfiguration.loadConfiguration(
@@ -98,10 +89,8 @@ public final class ConfigHelper {
         //Read all available config migrations
         Map<String, String> migrationFields;
         try {
-            InputStream migrationStream = FileHelper.getInputStreamForInternalFile("/" + MIGRATION_FILE);
+            InputStream migrationStream = loadInternalFile(plugin, MIGRATION_FILE, "internal migration paths");
             if (migrationStream == null) {
-                plugin.getLogger().log(Level.SEVERE, "Could not migrate the configuration, as the internal " +
-                        "migration paths could not be read!");
                 return false;
             }
             migrationFields = FileHelper.readKeyValuePairs(FileHelper.getBufferedReaderFromInputStream(migrationStream),
@@ -111,7 +100,7 @@ public final class ConfigHelper {
             return false;
         }
 
-        //Replace old config names with the new ones
+        // Replace old config names with the new ones
         for (String key : migrationFields.keySet()) {
             if (oldConfiguration.contains(key)) {
                 migrateProperty(migrationFields, key, oldConfiguration);
@@ -126,10 +115,8 @@ public final class ConfigHelper {
             newConfiguration.set(key, oldConfiguration.get(key));
         }
 
-        try {
+        // Save merged configuration
-            newConfiguration.save(config);
+        if (!StargateYamlConfiguration.saveConfiguration(plugin, newConfiguration)) {
-        } catch (IOException exception) {
-            plugin.getLogger().log(Level.WARNING, "Unable to save migrated config");
             return false;
         }
 
@@ -169,4 +156,25 @@ public final class ConfigHelper {
         oldConfiguration.set(key, null);
     }
 
+    /**
+     * Loads a file from the internal plugin .jar
+     *
+     * @param plugin          <p>The plugin to load the file from</p>
+     * @param fileName        <p>The file to load</p>
+     * @param fileDescription <p>The file description to use in error messages</p>
+     * @return <p>An input stream for the file, or null if the file could not be read</p>
+     */
+    @Nullable
+    private static InputStream loadInternalFile(@NotNull Plugin plugin, @NotNull String fileName,
+                                                @NotNull String fileDescription) {
+        InputStream configStream = FileHelper.getInputStreamForInternalFile("/" + fileName);
+        if (configStream == null) {
+            plugin.getLogger().log(Level.SEVERE, "Could not migrate the configuration, as the " + fileDescription +
+                    " could not be read!");
+            return null;
+        } else {
+            return configStream;
+        }
+    }
+
 }