EffForceAttack Damage Entity By Amount (SkriptLang#7878)

* Update EffForceAttack.java

* Update EffForceAttack.java

* Create EffForceAttack.sk

* Update EffForceAttack.java

* Edge Cases

* Use Runtime Error in test

Author: Absolutionism

src/main/java/ch/njol/skript/effects/EffForceAttack.java

@@ -1,61 +1,117 @@
 package ch.njol.skript.effects;
 
-import org.bukkit.entity.Entity;
-import org.bukkit.entity.LivingEntity;
-import org.bukkit.event.Event;
-import org.jetbrains.annotations.Nullable;
-
 import ch.njol.skript.Skript;
-import ch.njol.skript.doc.Description;
-import ch.njol.skript.doc.Examples;
-import ch.njol.skript.doc.Name;
-import ch.njol.skript.doc.RequiredPlugins;
-import ch.njol.skript.doc.Since;
+import ch.njol.skript.config.Node;
+import ch.njol.skript.doc.*;
 import ch.njol.skript.lang.Effect;
 import ch.njol.skript.lang.Expression;
 import ch.njol.skript.lang.SkriptParser.ParseResult;
+import ch.njol.skript.lang.SyntaxStringBuilder;
 import ch.njol.util.Kleenean;
+import org.bukkit.entity.Damageable;
+import org.bukkit.entity.Entity;
+import org.bukkit.entity.LivingEntity;
+import org.bukkit.event.Event;
+import org.jetbrains.annotations.Nullable;
+import org.skriptlang.skript.log.runtime.SyntaxRuntimeErrorProducer;
 
 @Name("Force Attack")
-@Description("Makes a living entity attack an entity with a melee attack.")
+@Description({
+	"Makes a living entity attack an entity with a melee attack.",
+	"Using 'attack' will make the attacker use the item in their main hand "
+		+ "and will apply extra data from the item, including enchantments and attributes.",
+	"Using 'damage' with a number of hearts will not account for the item in the main hand "
+		+ "and will always be the number provided."
+})
+@Example("""
+	spawn a wolf at location(0, 0, 0)
+	make last spawned wolf attack all players
+	""")
+@Example("""
+	spawn a zombie at location(0, 0, 0)
+	make player damage last spawned zombie by 2
+	""")
 @Examples({"spawn a wolf at player's location",
 	"make last spawned wolf attack player"})
-@Since("2.5.1")
+@Since("2.5.1, INSERT VERSION (multiple, amount)")
 @RequiredPlugins("Minecraft 1.15.2+")
-public class EffForceAttack extends Effect {
+public class EffForceAttack extends Effect implements SyntaxRuntimeErrorProducer {
 
 	static {
 		Skript.registerEffect(EffForceAttack.class,
-			"make %livingentities% attack %entity%",
-			"force %livingentities% to attack %entity%");
+			"make %livingentities% attack %entities%",
+			"force %livingentities% to attack %entities%",
+			"make %livingentities% damage %entities% by %number% [heart[s]]",
+			"force %livingentities% to damage %entities% by %number% [heart[s]]");
 	}
+
+	private Expression<LivingEntity> attackers;
+	private Expression<Entity> victims;
+	private @Nullable Expression<Number> amount;
+	private Node node;
 
-	@SuppressWarnings("null")
-	private Expression<LivingEntity> entities;
-	@SuppressWarnings("null")
-	private Expression<Entity> target;
-	
-	@Override
 	@SuppressWarnings("unchecked")
+	@Override
 	public boolean init(Expression<?>[] exprs, int matchedPattern, Kleenean isDelayed, ParseResult parseResult) {
-		entities = (Expression<LivingEntity>) exprs[0];
-		target = (Expression<Entity>) exprs[1];
+		attackers = (Expression<LivingEntity>) exprs[0];
+		victims = (Expression<Entity>) exprs[1];
+		if (matchedPattern >= 2)
+			amount = (Expression<Number>) exprs[2];
+		node = getParser().getNode();
 		return true;
 	}
 
 	@Override
-	protected void execute(Event e) {
-		Entity target = this.target.getSingle(e);
-		if (target != null) {
-			for (LivingEntity entity : entities.getArray(e)) {
-				entity.attack(target);
+	protected void execute(Event event) {
+		Double amount = null;
+		if (this.amount != null) {
+			Number number = this.amount.getSingle(event);
+			if (number == null)
+				return;
+			Double preAmount = number.doubleValue();
+			if (preAmount <= 0) {
+				error("Cannot damage an entity by 0 or less. Consider healing instead.");
+				return;
+			} else if (!Double.isFinite(preAmount)) {
+				return;
+			}
+			amount = preAmount * 2; // hearts
+		}
+
+		LivingEntity[] attackers = this.attackers.getArray(event);
+		Entity[] victims = this.victims.getArray(event);
+		if (amount == null) {
+			for (Entity victim : victims) {
+				for (LivingEntity attacker : attackers) {
+					attacker.attack(victim);
+				}
+			}
+		} else {
+			for (Entity victim : victims) {
+				if (!(victim instanceof Damageable damageable))
+					continue;
+				for (LivingEntity attacker : attackers) {
+					damageable.damage(amount, attacker);
+				}
 			}
 		}
 	}
-	
+
 	@Override
-	public String toString(@Nullable Event e, boolean debug) {
-		return "make " + entities.toString(e, debug) + " attack " + target.toString(e, debug);
+	public Node getNode() {
+		return node;
+	}
+
+	@Override
+	public String toString(Event event, boolean debug) {
+		SyntaxStringBuilder builder = new SyntaxStringBuilder(event, debug);
+		builder.append("make", attackers);
+		if (amount == null) {
+			builder.append("attack", victims);
+		} else {
+			builder.append("damage", victims, "by", amount);
+		}
+		return builder.toString();
 	}
 
 }

src/test/skript/tests/syntaxes/effects/EffForceAttack.sk

@@ -0,0 +1,63 @@
+
+test "force attack":
+	spawn a zombie at test-location:
+		set {_attacker} to entity
+	spawn a pig at test-location:
+		set {_victim} to entity
+
+	set {_max} to the max health of {_victim}
+	make {_attacker} attack {_victim}
+	assert the health of {_victim} < {_max} with "Victim should have taken damage"
+	assert the last damage of {_victim} is 1.5 with "Damage taken should be 1.5"
+
+	clear entity within {_attacker}
+	clear entity within {_victim}
+
+test "entity damage entity by amount":
+	spawn a zombie at test-location:
+		set {_attacker} to entity
+	spawn a pig at test-location:
+		set {_victim} to entity
+
+	set {_max} to the max health of {_victim}
+	make {_attacker} damage {_victim} by 5
+	assert the health of {_victim} < {_max} with "Victim should have taken damage"
+	assert the last damage of {_victim} is 5 with "Damage taken should be 5"
+
+	clear entity within {_attacker}
+	clear entity within {_victim}
+
+using error catching
+
+test "entity damage entity by negative":
+	spawn a zombie at test-location:
+		set {_attacker} to entity
+	spawn a pig at test-location:
+		set {_victim} to entity
+
+	set {_max} to the max health of {_victim}
+	catch errors:
+		make {_attacker} damage {_victim} by -2
+	set {_error} to "Cannot damage an entity by 0 or less. Consider healing instead."
+	assert last caught errors is {_error} with "Damaging by negative value did not throw error"
+
+	clear entity within {_attacker}
+	clear entity within {_victim}
+
+test "entity damage entity by infinity/NaN":
+	spawn a zombie at test-location:
+		set {_attacker} to entity
+	spawn a pig at test-location:
+		set {_victim} to entity
+
+	set {_max} to the max health of {_victim}
+	make {_attacker} damage {_victim} by infinity value
+	assert the health of {_victim} is {_max} with "Victim's health should be max - infinity value"
+	assert the last damage of {_victim} is 0 with "Victim should not have taken damage - infinity value"
+
+	make {_attacker} damage {_victim} by NaN value
+	assert the health of {_victim} is {_max} with "Victim's health should be max - NaN value"
+	assert the last damage of {_victim} is 0 with "Victim should not have taken damage - NaN value"
+
+	clear entity within {_attacker}
+	clear entity within {_victim}