Turret vessel spawner enemy (#52)

New EnemySpawnerComponent.gd (capability_id "spawner"): continuously
instantiates another enemy type beside its host at a fixed interval,
capped at max_alive concurrently, refilling as spawns die. Spawned
enemies are parented under the SPAWNER'S OWN PARENT rather than the
spawner itself, so they are siblings, not descendants - killing the
spawner can't free them, and a surface-hosted spawner (under
PlanetSetupHost) keeps its spawns under the same host instead of
leaking them to a hardcoded path, the same hazard #44 already closed
for pursuit/standoff/ranged-weapon components.

TurretSpawnerEnemyDefinition.tres: stationary (speed 0, no pursuit or
standoff component), max_hp 20 (~7x a chaser), a bulky octagon hull,
and its own acid-green glow distinct from chaser/sniper/artillery.
Registered in EnemyDefinitions.ORDER/DEFINITIONS - the map editor
palette (#48) picks it up with no editor code change.

Tests: new tests/test_turret_spawner_enemy.gd covers registration and
real definition defaults, no spawns without a fleet, spawning capped
at max_alive, a dead spawn's slot refilling, never moving, surviving
19 damage and dying on the 20th, and its spawns surviving its death
with their pursuit component intact. Screenshot beside a chaser
confirms the two read as visually distinct enemies. Full suite: 79/79.

Repo notes for the next agent, confirmed empirically this session:
- A node's set_process(false) call made before it has fully finished
  entering the tree doesn't reliably stick (already documented in
  tests/test_planet_atmosphere_transition.gd, and it bit this test
  too): BuildController._check_fleet_wipe() kept rebuilding a ship
  during an intended "empty fleet" test window even after disabling it
  in _initialize(). Do it in _process()'s first real tick instead,
  once _ready() cascades are confirmed complete.
- Overriding an @export interval (like spawn_interval) on an
  already-running component does NOT reset its own in-progress
  countdown timer - only changes what it resets TO on its next expiry.
  If the countdown already started at the OLD value before your
  override lands, reset the timer variable itself too, or the first
  real interval after the override silently uses the stale value.
- A capped spawner's freed-slot refill can land within a couple of
  frames once its interval is short - don't assert on an intermediate
  "just dropped by one" count that a fast interval can blow straight
  through before your next check runs. Assert the net effect instead
  (the specific killed instance is gone AND a replacement filled the
  slot) rather than an exact mid-transition snapshot.

🤖 Generated with Claude Code

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

EnemyDefinitions.gd

@@ -2,11 +2,12 @@ class_name EnemyDefinitions
 extends RefCounted
 
 const DEFAULT_ID: String = "chaser"
-const ORDER: PackedStringArray = ["chaser", "sniper", "artillery"]
+const ORDER: PackedStringArray = ["chaser", "sniper", "artillery", "turret_spawner"]
 const DEFINITIONS: Dictionary = {
 	"chaser": preload("res://ChaserEnemyDefinition.tres"),
 	"sniper": preload("res://SniperEnemyDefinition.tres"),
 	"artillery": preload("res://ArtilleryEnemyDefinition.tres"),
+	"turret_spawner": preload("res://TurretSpawnerEnemyDefinition.tres"),
 }
 
 

EnemySpawnerComponent.gd

@@ -0,0 +1,55 @@
+class_name EnemySpawnerComponent
+extends Node
+
+# Continuously spawns another enemy type beside its host, at a fixed
+# interval, capped at max_alive concurrently. The spawned enemies are
+# added as children of the spawner's OWN PARENT - not the spawner itself -
+# so killing the spawner never frees its already-spawned children (they
+# are siblings, not descendants) and so a surface-hosted spawner keeps its
+# spawns under the same host a `../Fleet`-style path assumption would miss
+# (see #44's note on why that hazard exists for anything parented under a
+# planet surface's PlanetSetupHost rather than directly under Main.tscn).
+
+var capability_id: String = "spawner"
+
+@export var spawn_interval: float = 4.0
+@export var spawned_enemy_id: String = "chaser"
+@export var max_alive: int = 6
+@export var spawn_radius: float = 90.0
+
+var spawn_timer: float = 0.0
+var spawned: Array = []
+var enemy_scene: PackedScene = preload("res://Enemy.tscn")
+
+
+func tick(delta: float) -> void:
+	spawned = spawned.filter(func(node): return is_instance_valid(node))
+	if spawned.size() >= max_alive:
+		return
+
+	spawn_timer -= delta
+	if spawn_timer > 0.0:
+		return
+	spawn_timer = spawn_interval
+
+	var fleet: Node2D = get_tree().get_first_node_in_group("player_fleet")
+	if fleet == null or fleet.ships.is_empty():
+		return
+
+	var spawner: Node2D = get_parent()
+	var host: Node = spawner.get_parent()
+	if host == null:
+		return
+
+	var angle: float = randf() * TAU
+	var offset: Vector2 = Vector2(cos(angle), sin(angle)) * spawn_radius
+
+	var new_enemy: Node2D = enemy_scene.instantiate()
+	new_enemy.enemy_id = spawned_enemy_id
+	# spawner.position is already expressed in `host`'s local space, and
+	# new_enemy is about to be added to that same `host` - unlike
+	# EnemyRangedWeaponComponent's projectile, which reparents to root and
+	# needs global_position, there is no space conversion needed here.
+	new_enemy.position = spawner.position + offset
+	host.add_child(new_enemy)
+	spawned.append(new_enemy)

EnemySpawnerComponent.tscn

@@ -0,0 +1,6 @@
+[gd_scene load_steps=2 format=3]
+
+[ext_resource type="Script" path="res://EnemySpawnerComponent.gd" id="1"]
+
+[node name="EnemySpawnerComponent" type="Node"]
+script = ExtResource("1")

TurretSpawnerEnemyDefinition.tres

@@ -0,0 +1,16 @@
+[gd_resource type="Resource" script_class="EnemyDefinition" load_steps=3 format=3]
+
+[ext_resource type="Script" path="res://EnemyDefinition.gd" id="1"]
+[ext_resource type="PackedScene" path="res://EnemySpawnerComponent.tscn" id="2"]
+
+[resource]
+script = ExtResource("1")
+enemy_id = "turret_spawner"
+display_name = "Turret Spawner"
+max_hp = 20
+speed = 0.0
+acceleration = 0.0
+rotation_speed = 0.0
+hull_points = PackedVector2Array(0, -32, 22.6, -22.6, 32, 0, 22.6, 22.6, 0, 32, -22.6, 22.6, -32, 0, -22.6, -22.6)
+glow_color = Color(0.68, 0.92, 0.18, 1)
+component_scenes = Array[PackedScene]([ExtResource("2")])

tests/_turret_vs_chaser_preview.gd

@@ -0,0 +1,60 @@
+extends Node2D
+
+# Preview, not a test - #52's "visually distinguishable from a chaser"
+# acceptance criterion. Same setup shape as _sniper_vs_chaser_preview.gd -
+# see that file's header note for why setup is deferred to the first
+# _process() tick and the tree gets paused once everything is placed.
+#
+#   bash tests/screenshot.sh res://tests/_turret_vs_chaser_preview.tscn /tmp/turret.png 20 720x1280
+
+var main: Node
+var setup_done: bool = false
+
+
+func _ready() -> void:
+	GameState.buildings.clear()
+	GameState.extractors.clear()
+	GameState.transporters.clear()
+	main = load("res://Main.tscn").instantiate()
+	add_child(main)
+	main.get_node("BackgroundLayer").visible = false
+	main.get_node("AsteroidField").visible = false
+	main.get_node("PlanetField").visible = false
+	main.get_node("BuildingField").visible = false
+	main.get_node("EnemySpawner").set_process(false)
+	main.get_node("AsteroidField").set_process(false)
+
+
+func _process(_delta: float) -> void:
+	if setup_done:
+		return
+	setup_done = true
+
+	var fleet: Node = main.get_node("Fleet")
+	for ship in fleet.ships:
+		if is_instance_valid(ship):
+			ship.set_physics_process(false)
+	fleet.spawn_ships(0, Vector2.ZERO)
+	for ship in fleet.ships:
+		if is_instance_valid(ship):
+			ship.set_physics_process(false)
+			ship.queue_free()
+	fleet.ships.clear()
+	for projectile in get_tree().get_nodes_in_group("player_projectiles"):
+		projectile.queue_free()
+
+	var chaser: Node = load("res://Enemy.tscn").instantiate()
+	chaser.enemy_id = "chaser"
+	chaser.position = Vector2(-160, -80)
+	main.add_child(chaser)
+	chaser.speed = 0.0
+
+	var turret: Node = load("res://Enemy.tscn").instantiate()
+	turret.enemy_id = "turret_spawner"
+	turret.position = Vector2(160, -80)
+	main.add_child(turret)
+
+	var camera: Camera2D = main.get_node("Camera2D")
+	camera.zoom = Vector2(1.4, 1.4)
+
+	get_tree().paused = true

tests/_turret_vs_chaser_preview.tscn

@@ -0,0 +1,6 @@
+[gd_scene load_steps=2 format=3]
+
+[ext_resource type="Script" path="res://tests/_turret_vs_chaser_preview.gd" id="1"]
+
+[node name="TurretVsChaserPreview" type="Node2D"]
+script = ExtResource("1")

tests/test_turret_spawner_enemy.gd

@@ -0,0 +1,192 @@
+extends SceneTree
+
+# Headless gameplay test: run with
+#   godot --headless -s res://tests/test_turret_spawner_enemy.gd
+# Forgejo #52: a stationary, high-HP enemy that continuously spawns chasers
+# beside itself. Verifies:
+#   1. registered in EnemyDefinitions - the map editor palette (#48) is
+#      generated from EnemyDefinitions.all(), so this alone is what makes
+#      it placeable, with no editor code change
+#   2. spawns nothing while there is no fleet (or an empty one)
+#   3. once a fleet exists, spawns one enemy per spawn_interval, stopping
+#      at max_alive
+#   4. a spawn dying frees its slot, and the next interval fills it again
+#   5. the turret itself never moves
+#   6. survives 19 damage, dies on the 20th
+#   7. its already-spawned children survive its death - they are siblings
+#      under its own parent, not descendants, so killing it can't free them
+#
+# spawn_interval/max_alive are overridden to small test-friendly values
+# directly on the instantiated component, the same way tests/
+# _artillery_telegraph_rocky_preview.gd pins ArtilleryShell's telegraph_time -
+# the definition's real defaults (4.0s / 6 alive) are only asserted once,
+# structurally, before the override.
+
+var game_state: Node
+var main: Node
+var fleet: Node
+var turret: Node
+var spawner: Node
+var stage: int = 0
+var elapsed: float = 0.0
+var turret_start_position: Vector2
+var one_spawn_ref: Node
+
+
+func _initialize() -> void:
+	game_state = root.get_node("GameState")
+
+	# --- 1. registered, with the definition's real defaults intact ---
+	if not EnemyDefinitions.ORDER.has("turret_spawner"):
+		_fail("turret_spawner is not in EnemyDefinitions.ORDER - the map editor palette would never show it")
+		return
+	var definition: Resource = EnemyDefinitions.get_definition("turret_spawner")
+	if definition.max_hp != 20:
+		_fail("turret_spawner max_hp is %d, expected 20 (a decent amount of life)" % definition.max_hp)
+		return
+	if definition.speed != 0.0:
+		_fail("turret_spawner speed is %s, expected 0.0 (stationary)" % definition.speed)
+		return
+
+	main = load("res://Main.tscn").instantiate()
+	root.add_child(main)
+	fleet = main.get_node("Fleet")
+
+
+func _process(delta: float) -> bool:
+	elapsed += delta
+	match stage:
+		0:
+			if elapsed < 0.1:
+				return false
+			# This has to happen here, not in _initialize() - a node's
+			# set_process(false) call made before it has fully finished
+			# entering the tree doesn't reliably stick, since the engine's
+			# own deferred tree-entry finalization can reset it back to
+			# enabled. By now _ready() cascades are confirmed complete.
+			main.get_node("EnemySpawner").set_process(false)
+			main.get_node("AsteroidField").set_process(false)
+			# BuildController._check_fleet_wipe() runs every _process() tick
+			# and rebuilds a single ship the moment fleet.ships is empty -
+			# the exact "empty fleet" state stage 2 needs to hold for a while.
+			main.get_node("BuildController").set_process(false)
+
+			# Empty the fleet (gotcha: spawn_ships(0,...) still leaves one
+			# default interceptor - clear explicitly).
+			for ship in fleet.ships:
+				if is_instance_valid(ship):
+					ship.queue_free()
+			fleet.ships.clear()
+
+			turret = load("res://Enemy.tscn").instantiate()
+			turret.enemy_id = "turret_spawner"
+			turret.position = Vector2(500, 500)
+			turret_start_position = turret.position
+			main.add_child(turret)
+			elapsed = 0.0
+			stage = 1
+			return false
+		1:
+			if elapsed < 0.15:
+				return false
+			spawner = turret.get_component("spawner")
+			if spawner == null:
+				return _fail("turret_spawner has no 'spawner' capability component")
+			# --- 2. no fleet -> no spawns, even past several intervals ---
+			spawner.spawn_interval = 0.1
+			spawner.max_alive = 3
+			spawner.spawn_radius = 50.0
+			# spawn_timer already started counting down from the definition's
+			# real default (4.0s) on the component's very first tick, before
+			# this override could reach it - changing spawn_interval alone
+			# only affects the NEXT reset, not the countdown already running.
+			# Reset it explicitly so the override takes effect immediately.
+			spawner.spawn_timer = 0.0
+			elapsed = 0.0
+			stage = 2
+			return false
+		2:
+			if elapsed < 0.6:
+				return false
+			if spawner.spawned.size() > 0:
+				return _fail("spawner spawned %d enemies with no fleet present" % spawner.spawned.size())
+
+			# --- give it a fleet to spawn against ---
+			fleet.spawn_ships(1, Vector2(-2000, -2000))
+			elapsed = 0.0
+			stage = 3
+			return false
+		3:
+			# --- 3. spawns, capped at max_alive ---
+			if elapsed < spawner.spawn_interval * (spawner.max_alive + 2) + 0.3:
+				return false
+			if spawner.spawned.size() != spawner.max_alive:
+				return _fail("spawner has %d alive after plenty of time, expected max_alive=%d" % [
+					spawner.spawned.size(), spawner.max_alive
+				])
+			for spawn in spawner.spawned:
+				if spawn.enemy_id != "chaser":
+					return _fail("a spawn has enemy_id '%s', expected 'chaser'" % spawn.enemy_id)
+				if spawn.get_parent() != turret.get_parent():
+					return _fail("a spawn is not parented under the turret's own parent - it would not survive the turret's death correctly")
+
+			# --- 5. never moves ---
+			if turret.position != turret_start_position:
+				return _fail("turret_spawner moved from %s to %s" % [turret_start_position, turret.position])
+
+			# --- 4. a dead spawn frees its slot and gets refilled ---
+			one_spawn_ref = spawner.spawned[0]
+			one_spawn_ref.take_damage(999)
+			elapsed = 0.0
+			stage = 4
+			return false
+		4:
+			# --- 4. a dead spawn frees its slot, and the interval refills it ---
+			# spawn_interval is short enough (0.1s, overridden above) that the
+			# refill can land within a couple of frames of the kill - there is
+			# no reliably observable moment where the count sits at max_alive-1
+			# and stays there, so this checks the net effect once things have
+			# settled: the killed spawn specifically is gone, and a fresh one
+			# took its slot back up to max_alive, rather than checking for an
+			# intermediate dip that a fast interval can blow straight through.
+			if elapsed < spawner.spawn_interval + 0.3:
+				return false
+			if is_instance_valid(one_spawn_ref):
+				return _fail("killed spawn is still valid after take_damage(999)")
+			if spawner.spawned.has(one_spawn_ref):
+				return _fail("the killed spawn is still tracked in spawner.spawned")
+			if spawner.spawned.size() != spawner.max_alive:
+				return _fail("spawner did not refill the freed slot (has %d, expected %d)" % [
+					spawner.spawned.size(), spawner.max_alive
+				])
+
+			# --- 6 + 7. damage, death, and spawns surviving the death ---
+			var surviving_spawns: Array = spawner.spawned.duplicate()
+			turret.take_damage(19)
+			if not is_instance_valid(turret):
+				return _fail("turret_spawner died from 19 damage - should take 20 to kill")
+			turret.take_damage(1)
+			elapsed = 0.0
+			stage = 6
+			one_spawn_ref = surviving_spawns[0]
+			return false
+		6:
+			if elapsed < 0.15:
+				return false
+			if is_instance_valid(turret):
+				return _fail("turret_spawner survived 20 total damage")
+			if not is_instance_valid(one_spawn_ref):
+				return _fail("a spawn was freed when its spawner died - they are siblings, not descendants")
+			if not one_spawn_ref.has_capability("pursuit"):
+				return _fail("a surviving spawn lost its pursuit component - it should still chase the fleet")
+
+			print("TEST_TURRET_SPAWNER_ENEMY: PASS")
+			quit(0)
+			return true
+	return false
+
+
+func _fail(message: String) -> bool:
+	print("TEST_TURRET_SPAWNER_ENEMY: FAIL (%s)" % message)
+	quit(1)
+	return true