Add modifyTrack method to TrackManager (#3823)

api/src/main/java/net/luckperms/api/track/TrackManager.java

@@ -96,6 +96,27 @@ public interface TrackManager {
      */
     @NonNull CompletableFuture<Void> deleteTrack(@NonNull Track track);
 
+    /**
+     * Loads (or creates) a track from the plugin's storage provider, applies the given {@code action},
+     * then saves the track's data back to storage.
+     *
+     * <p>This method effectively calls {@link #createAndLoadTrack(String)}, followed by the
+     * {@code action}, then {@link #saveTrack(Track)}, and returns an encapsulation of the whole
+     * process as a {@link CompletableFuture}. </p>
+     *
+     * @param name the name of the track
+     * @param action the action to apply to the track
+     * @return a future to encapsulate the operation
+     * @since 5.5
+     */
+    default @NonNull CompletableFuture<Void> modifyTrack(@NonNull String name, @NonNull Consumer<? super Track> action) {
+        /* This default method is overridden in the implementation, and is just here
+           to demonstrate what this method does in the API sources. */
+        return createAndLoadTrack(name)
+                .thenApplyAsync(track -> { action.accept(track); return track; })
+                .thenCompose(this::saveTrack);
+    }
+
     /**
      * Loads all tracks into memory.
      *

common/src/main/java/me/lucko/luckperms/common/api/implementation/ApiTrackManager.java

@@ -38,6 +38,7 @@ import java.util.Objects;
 import java.util.Optional;
 import java.util.Set;
 import java.util.concurrent.CompletableFuture;
+import java.util.function.Consumer;
 
 public class ApiTrackManager extends ApiAbstractManager<Track, net.luckperms.api.track.Track, TrackManager<?>> implements net.luckperms.api.track.TrackManager {
     public ApiTrackManager(LuckPermsPlugin plugin, TrackManager<?> handle) {
@@ -74,6 +75,19 @@ public class ApiTrackManager extends ApiAbstractManager<Track, net.luckperms.api
         return this.plugin.getStorage().deleteTrack(ApiTrack.cast(track), DeletionCause.API);
     }
 
+    @Override
+    public @NonNull CompletableFuture<Void> modifyTrack(@NonNull String name, @NonNull Consumer<? super net.luckperms.api.track.Track> action) {
+        Objects.requireNonNull(name, "name");
+        Objects.requireNonNull(action, "action");
+
+        return this.plugin.getStorage().createAndLoadTrack(name, CreationCause.API)
+                .thenApplyAsync(track -> {
+                    action.accept(track.getApiProxy());
+                    return track;
+                }, this.plugin.getBootstrap().getScheduler().async())
+                .thenCompose(track -> this.plugin.getStorage().saveTrack(track));
+    }
+
     @Override
     public @NonNull CompletableFuture<Void> loadAllTracks() {
         return this.plugin.getStorage().loadAllTracks();