Warn if you register replacements after commands

core/src/main/java/co/aikar/commands/BukkitCommandManager.java

@@ -101,6 +101,11 @@ public class BukkitCommandManager extends CommandManager {
         return completions;
     }
 
+    @Override
+    public boolean hasRegisteredCommands() {
+        return !registeredCommands.isEmpty();
+    }
+
     @Override
     public void registerCommand(BaseCommand command) {
         final String plugin = this.plugin.getName().toLowerCase();

core/src/main/java/co/aikar/commands/CommandManager.java

@@ -32,7 +32,7 @@ import java.util.Map;
 public abstract class CommandManager {
 
     protected Map<String, RootCommand> rootCommands = new HashMap<>();
-    protected CommandReplacements replacements = new CommandReplacements();
+    protected CommandReplacements replacements = new CommandReplacements(this);
 
     /**
      * Gets the command contexts manager
@@ -66,6 +66,7 @@ public abstract class CommandManager {
      * @return boolean
      */
     public abstract void registerCommand(BaseCommand command);
+    public abstract boolean hasRegisteredCommands();
 
     public abstract TimingManager getTimings();
 

core/src/main/java/co/aikar/commands/CommandReplacements.java

@@ -32,6 +32,12 @@ import java.util.regex.Pattern;
  * Manages replacement template strings
  */
 public class CommandReplacements {
+
+    private final CommandManager manager;
+
+    CommandReplacements(CommandManager manager) {
+        this.manager = manager;
+    }
     private final Map<String, Map.Entry<Pattern, String>> replacements = new LinkedHashMap<>();
 
     public void addReplacements(String... replacements) {
@@ -44,6 +50,11 @@ public class CommandReplacements {
     }
 
     public String addReplacement(String key, String val) {
+        if (this.manager.hasRegisteredCommands()) {
+            ACFLog.severe("You are registering replacements after you have registered your commands!");
+            ACFLog.severe("This is not allowed, and this replacement (" + key + ") will not work for any previously registered command.");
+        }
+
         key = ACFPatterns.PERCENTAGE.matcher(key.toLowerCase()).replaceAll("");
         Pattern pattern = Pattern.compile("%" + Pattern.quote(key) + "\\b", Pattern.CASE_INSENSITIVE);