Add is skript command condition (#3925)

src/main/java/ch/njol/skript/command/Commands.java

@@ -506,10 +506,10 @@ else if (aliases.get(0).isEmpty())
 		return c;
 	}
 
-//	public static boolean skriptCommandExists(final String command) {
-//		final ScriptCommand c = commands.get(command);
-//		return c != null && c.getName().equals(command);
-//	}
+	public static boolean skriptCommandExists(final String command) {
+		final ScriptCommand c = commands.get(command);
+		return c != null && c.getName().equals(command);
+	}
 
 	public static void registerCommand(final ScriptCommand command) {
 		// Validate that there are no duplicates

src/main/java/ch/njol/skript/conditions/CondIsSkriptCommand.java

@@ -0,0 +1,55 @@
+/**
+ *   This file is part of Skript.
+ *
+ *  Skript is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  Skript is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with Skript.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Copyright Peter Güttinger, SkriptLang team and contributors
+ */
+package ch.njol.skript.conditions;
+
+import static ch.njol.skript.command.Commands.skriptCommandExists;
+
+import ch.njol.skript.conditions.base.PropertyCondition;
+import ch.njol.skript.doc.Description;
+import ch.njol.skript.doc.Examples;
+import ch.njol.skript.doc.Name;
+import ch.njol.skript.doc.Since;
+
+@Name("Is a Skript command")
+@Description("Checks whether a command/string is a custom Skript command.")
+@Examples(
+	{"# Example 1",
+	"on command:", 
+	"\tcommand is a skript command",
+	"",
+	"# Example 2",
+	"\"sometext\" is a skript command"})
+@Since("INSERT VERSION")
+public class CondIsSkriptCommand extends PropertyCondition<String> {
+
+	static {
+		register(CondIsSkriptCommand.class, PropertyType.BE, "[a] s(k|c)ript (command|cmd)", "string");
+	}
+
+	@Override
+	public boolean check(String cmd) {
+		return skriptCommandExists(cmd);
+	}
+
+	@Override
+	protected String getPropertyName() {
+		return "skript command";
+	}
+
+}

src/main/java/ch/njol/skript/events/EvtCommand.java

@@ -37,7 +37,7 @@
 public class EvtCommand extends SkriptEvent { // TODO condition to check whether a given command exists, & a conditon to check whether it's a custom skript command
 	static {
 		Skript.registerEvent("Command", EvtCommand.class, CollectionUtils.array(PlayerCommandPreprocessEvent.class, ServerCommandEvent.class), "command [%-string%]")
-				.description("Called when a player enters a command (not neccessarily a Skript command).")
+				.description("Called when a player enters a command (not necessarily a Skript command) but you can check if command is a skript command, see <a href='conditions.html#CondIsSkriptCommand'>Is a Skript command condition</a>.")
 				.examples("on command:", "on command \"/stop\":", "on command \"pm Njol \":")
 				.since("2.0");
 	}