Add entity size expression

src/main/java/ch/njol/skript/expressions/ExprEntitySize.java

@@ -0,0 +1,107 @@
+package ch.njol.skript.expressions;
+
+import ch.njol.skript.classes.Changer.ChangeMode;
+import ch.njol.skript.doc.Description;
+import ch.njol.skript.doc.Example;
+import ch.njol.skript.doc.Name;
+import ch.njol.skript.doc.Since;
+import ch.njol.skript.expressions.base.SimplePropertyExpression;
+import ch.njol.util.Math2;
+import ch.njol.util.coll.CollectionUtils;
+import org.bukkit.entity.LivingEntity;
+import org.bukkit.entity.Phantom;
+import org.bukkit.entity.Slime;
+import org.bukkit.event.Event;
+import org.jetbrains.annotations.Nullable;
+
+@Name("Entity Size")
+@Description({
+	"Changes the entity size of slimes and phantoms. This is not the same as changing the scale attribute of an entity.",
+	"When changing the size of a slime, its health is fully resorted and will have changes done to its max health, movement speed and attack damage.",
+	"The default minecraft size of a slime is anywhere between 0 and 2, with a maximum of 126.",
+	"The default minecraft size of a phantom is 0 with a maximum size of 64."
+})
+@Example("""
+	spawn a slime at player:
+		set entity size of event-entity to 5
+		set name of event-entity to "King Slime Jorg"
+	""")
+@Since("INSERT VERSION")
+public class ExprEntitySize extends SimplePropertyExpression<LivingEntity, Integer> {
+
+	private static final int MAXIMUM_SLIME_SIZE = 127;
+	private static final int MAXIMUM_PHANTOM_SIZE = 64;
+
+	static {
+		register(ExprEntitySize.class, Integer.class, "entity size", "livingentities");
+	}
+
+	@Override
+	public @Nullable Integer convert(LivingEntity from) {
+		if (from instanceof Phantom phantom) {
+			return phantom.getSize();
+		} else if (from instanceof Slime slime) {
+			// Skript follows the nbt format of 0-126 for slimes, as bukkit uses a 1-127 value
+			return slime.getSize()-1;
+		}
+		return null;
+	}
+
+	@Override
+	public Class<?> @Nullable [] acceptChange(ChangeMode mode) {
+		return switch (mode) {
+			case ADD, REMOVE, SET -> CollectionUtils.array(Number.class);
+			case RESET -> CollectionUtils.array();
+			default -> null;
+		};
+	}
+
+	@Override
+	public void change(Event event, Object @Nullable [] delta, ChangeMode mode) {
+		if (delta == null && mode != ChangeMode.RESET)
+			return;
+
+		double deltaSizeDouble = delta != null ? ((Number) delta[0]).doubleValue() : 0;
+		if (Double.isNaN(deltaSizeDouble) || Double.isInfinite(deltaSizeDouble))
+			return;
+		// Due to how double to int conversions happen, we are required to reassign from delta to prevent integer overflows
+		int sizeDelta = delta != null ? ((Number) delta[0]).intValue() : 0;
+		if (mode == ChangeMode.REMOVE)
+			sizeDelta = -sizeDelta;
+
+		switch (mode) {
+			case ADD, REMOVE -> {
+				for (LivingEntity entity : getExpr().getArray(event)) {
+					if (entity instanceof Phantom phantom) {
+						int newSize = Math2.fit(0, (phantom.getSize() + sizeDelta), MAXIMUM_PHANTOM_SIZE);
+						phantom.setSize(newSize);
+					} else if (entity instanceof Slime slime) {
+						int newSize = Math2.fit(1, (slime.getSize() + sizeDelta), MAXIMUM_SLIME_SIZE);
+						slime.setSize(newSize);
+					}
+				}
+			}
+			case SET, RESET -> {
+				for (LivingEntity entity : getExpr().getArray(event)) {
+					if (entity instanceof Phantom phantom) {
+						phantom.setSize(Math2.fit(0, sizeDelta, MAXIMUM_PHANTOM_SIZE));
+					} else if (entity instanceof Slime slime) {
+						// Skript follows the nbt format of 0-126 for slimes, as bukkit uses a 1-127 value
+						slime.setSize(Math2.fit(1, sizeDelta+1, MAXIMUM_SLIME_SIZE));
+					}
+				}
+			}
+		}
+	}
+
+	@Override
+	public Class<? extends Integer> getReturnType() {
+		return Integer.class;
+	}
+
+	@Override
+	protected String getPropertyName() {
+		return "entity size";
+	}
+
+}

src/test/skript/tests/syntaxes/expressions/ExprEntitySize.sk

@@ -0,0 +1,121 @@
+
+test "ExprEntitySize - Slimes":
+
+	spawn a slime at test location:
+		make entity invulnerable
+		set {_entity} to entity
+
+	# Changer - Set
+	set entity size of {_entity} to 5
+	assert entity size of {_entity} is 5
+
+	set entity size of {_entity} to nan value
+	assert entity size of {_entity} is 5
+
+	set entity size of {_entity} to infinity value
+	assert entity size of {_entity} is 5
+
+	set entity size of {_entity} to -5
+	assert entity size of {_entity} is 0
+
+	# Changer - Add
+	add 10 to entity size of {_entity}
+	assert entity size of {_entity} is 10
+
+	add -5 to entity size of {_entity}
+	assert entity size of {_entity} is 5
+
+	add 5000000000 to entity size of {_entity}
+	assert entity size of {_entity} is 126
+
+	add nan value to entity size of {_entity}
+	assert entity size of {_entity} is 126
+
+	add infinity value to entity size of {_entity}
+	assert entity size of {_entity} is 126
+
+	# Changer - Remove
+	remove 100 from entity size of {_entity}
+	assert entity size of {_entity} is 26
+
+	remove -10 from entity size of {_entity}
+	assert entity size of {_entity} is 36
+
+	remove nan value from entity size of {_entity}
+	assert entity size of {_entity} is 36
+
+	remove infinity value from entity size of {_entity}
+	assert entity size of {_entity} is 36
+
+	remove 100 from entity size of {_entity}
+	assert entity size of {_entity} is 0
+
+	# Changer - Reset
+
+	add 3 to entity size of {_entity}
+	assert entity size of {_entity} is 3
+
+	reset entity size of {_entity}
+	assert entity size of {_entity} is 0
+
+	# Cleanup
+	delete entity within {_entity}
+
+test "ExprEntitySize - Phantoms":
+	spawn a phantom at test location:
+		make entity invulnerable
+		set {_entity} to entity
+
+	set entity size of {_entity} to 5
+	assert entity size of {_entity} is 5
+
+	set entity size of {_entity} to nan value
+	assert entity size of {_entity} is 5
+
+	set entity size of {_entity} to infinity value
+	assert entity size of {_entity} is 5
+
+	set entity size of {_entity} to -5
+	assert entity size of {_entity} is 0
+
+	# Changer - Add
+	add 10 to entity size of {_entity}
+	assert entity size of {_entity} is 10
+
+	add -5 to entity size of {_entity}
+	assert entity size of {_entity} is 5
+
+	add 5000000000 to entity size of {_entity}
+	assert entity size of {_entity} is 64
+
+	add nan value to entity size of {_entity}
+	assert entity size of {_entity} is 64
+
+	add infinity value to entity size of {_entity}
+	assert entity size of {_entity} is 64
+
+	# Changer - Remove
+	remove 40 from entity size of {_entity}
+	assert entity size of {_entity} is 24
+
+	remove -10 from entity size of {_entity}
+	assert entity size of {_entity} is 34
+
+	remove nan value from entity size of {_entity}
+	assert entity size of {_entity} is 34
+
+	remove infinity value from entity size of {_entity}
+	assert entity size of {_entity} is 34
+
+	remove 100 from entity size of {_entity}
+	assert entity size of {_entity} is 0
+
+	# Changer - Reset
+	add 3 to entity size of {_entity}
+	assert entity size of {_entity} is 3
+
+	reset entity size of {_entity}
+	assert entity size of {_entity} is 0
+
+	# Cleanup
+	delete entity within {_entity}