Add carrier vessel (#57)

An unarmed hauler with no weapon component - only VesselCargoComponent,
so it structurally cannot fire, the same pattern that already made the
shield vessel weaponless after #35. Its cargo_capacity (120, six
interceptors' worth) makes it the first real payoff for #56's fleet
hold cap.

Wired into the crafter, hangar and ship lab menus, all of which were
already generic over VesselDefinitions.fleet()/.all() - only the
per-vessel UI *nodes* are hand-placed (Main.tscn), not the logic, so
this repacks those three button rows to 4/4/5 columns and extends
BuildController's matching onready arrays. No new signal handlers were
needed.

Also fixes test_vessel_composition.gd's hardcoded fleet-catalog size
(3 -> 4) now that a fourth vessel is fleet-eligible.

BuildController.gd

@@ -31,11 +31,13 @@ const VESSEL_DEFINITIONS = preload("res://VesselDefinitions.gd")
 @onready var lab_vessel_buttons: Array = [
 	get_node("../UI/LabMenu/VesselA"), get_node("../UI/LabMenu/VesselB"),
 	get_node("../UI/LabMenu/VesselC"), get_node("../UI/LabMenu/VesselD"),
+	get_node("../UI/LabMenu/VesselE"),
 ]
 @onready var lab_vessel_label: Label = get_node("../UI/LabMenu/VesselLabel")
 @onready var lab_vessel_labels: Array = [
 	get_node("../UI/LabMenu/VesselALabel"), get_node("../UI/LabMenu/VesselBLabel"),
 	get_node("../UI/LabMenu/VesselCLabel"), get_node("../UI/LabMenu/VesselDLabel"),
+	get_node("../UI/LabMenu/VesselELabel"),
 ]
 @onready var lab_detail: Label = get_node("../UI/LabMenu/DetailLabel")
 @onready var lab_status: Label = get_node("../UI/LabMenu/StatusLabel")
@@ -63,21 +65,25 @@ const VESSEL_DEFINITIONS = preload("res://VesselDefinitions.gd")
 	get_node("../UI/HangarMenu/AvailableInterceptor"),
 	get_node("../UI/HangarMenu/AvailableShield"),
 	get_node("../UI/HangarMenu/AvailableGasBomber"),
+	get_node("../UI/HangarMenu/AvailableCarrier"),
 ]
 @onready var hangar_available_labels: Array = [
 	get_node("../UI/HangarMenu/AvailableInterceptorLabel"),
 	get_node("../UI/HangarMenu/AvailableShieldLabel"),
 	get_node("../UI/HangarMenu/AvailableGasBomberLabel"),
+	get_node("../UI/HangarMenu/AvailableCarrierLabel"),
 ]
 @onready var hangar_fleet_slots: Array = [
 	get_node("../UI/HangarMenu/FleetInterceptor"),
 	get_node("../UI/HangarMenu/FleetShield"),
 	get_node("../UI/HangarMenu/FleetGasBomber"),
+	get_node("../UI/HangarMenu/FleetCarrier"),
 ]
 @onready var hangar_fleet_labels: Array = [
 	get_node("../UI/HangarMenu/FleetInterceptorLabel"),
 	get_node("../UI/HangarMenu/FleetShieldLabel"),
 	get_node("../UI/HangarMenu/FleetGasBomberLabel"),
+	get_node("../UI/HangarMenu/FleetCarrierLabel"),
 ]
 var build_menu_entries: Array = []
 
@@ -103,11 +109,13 @@ var lab_building_id: int = 0
 @onready var craft_shield_label: Label = get_node("../UI/CraftMenu/ShieldLabel")
 @onready var craft_gas_bomber_button: IconButton = get_node("../UI/CraftMenu/GasBomberButton")
 @onready var craft_gas_bomber_label: Label = get_node("../UI/CraftMenu/GasBomberLabel")
+@onready var craft_carrier_button: IconButton = get_node("../UI/CraftMenu/CarrierButton")
+@onready var craft_carrier_label: Label = get_node("../UI/CraftMenu/CarrierLabel")
 @onready var craft_vessel_buttons: Array = [
-	craft_interceptor_button, craft_shield_button, craft_gas_bomber_button,
+	craft_interceptor_button, craft_shield_button, craft_gas_bomber_button, craft_carrier_button,
 ]
 @onready var craft_vessel_labels: Array = [
-	craft_interceptor_label, craft_shield_label, craft_gas_bomber_label,
+	craft_interceptor_label, craft_shield_label, craft_gas_bomber_label, craft_carrier_label,
 ]
 
 # --- the transfer panel (#24) ---------------------------------------------

CarrierCapacityUpgrade.tres

@@ -0,0 +1,11 @@
+[gd_resource type="Resource" script_class="VesselUpgradeDefinition" load_steps=2 format=3]
+[ext_resource type="Script" path="res://VesselUpgradeDefinition.gd" id="1"]
+[resource]
+script = ExtResource("1")
+upgrade_id = "car_capacity"
+display_name = "Reinforced Hold"
+description = "+30 cargo capacity per level."
+base_cost = 40
+max_level = 3
+icon = 21
+additive_modifiers = {"cargo_capacity": 30.0}

CarrierVesselDefinition.tres

@@ -0,0 +1,25 @@
+[gd_resource type="Resource" script_class="VesselDefinition" load_steps=4 format=3]
+[ext_resource type="Script" path="res://VesselDefinition.gd" id="1"]
+[ext_resource type="PackedScene" path="res://VesselCargoComponent.tscn" id="2"]
+[ext_resource type="Resource" path="res://CarrierCapacityUpgrade.tres" id="3"]
+[resource]
+script = ExtResource("1")
+definition_id = "carrier"
+display_name = "Carrier"
+description = "Unarmed hauler with a much larger hold than any combat vessel. Cannot fire."
+build_cost = 24
+build_time = 20.0
+icon = 34
+glow_color = Color(1, 0.78, 0.3, 1)
+hull_points = PackedVector2Array(-32, -10, -18, -18, 18, -18, 32, -10, 32, 14, -32, 14)
+fleet_eligible = true
+capabilities = PackedStringArray("cargo")
+component_scenes = Array[PackedScene]([ExtResource("2")])
+base_stats = {"max_speed": 380.0, "acceleration": 360.0, "delivery_speed": 180.0, "cargo_capacity": 120.0}
+upgrades = Array[Resource]([ExtResource("3")])
+unlock_id = "unlock_carrier"
+unlock_name = "Unlock Carrier"
+unlock_description = "Research a dedicated hauler hull that trades weapons for a much larger cargo hold."
+unlock_cost = 0
+unlock_resource_costs = {"ore": 60}
+unlock_icon = -1

GameState.gd

@@ -463,6 +463,7 @@ const VESSEL_INTERCEPTOR: String = "interceptor"
 const VESSEL_SHIELD: String = "shield"
 const VESSEL_GAS_BOMBER: String = "gas_bomber"
 const VESSEL_TRANSPORTER: String = "transporter"
+const VESSEL_CARRIER: String = "carrier"
 
 # Compatibility constants for callers and old tests. Runtime metadata is
 # resolved from VesselDefinition below.

IconButton.gd

@@ -35,6 +35,9 @@ enum Icon {
 	# inserting there would silently renumber every icon int already
 	# stored in existing scenes (#54).
 	GAS_BURNER,
+	# Same append-only rule (#57): a wide hauler hull, distinct from every
+	# vessel glyph above.
+	CARRIER_VESSEL,
 }
 
 # Size the glyphs were originally drawn against. Every glyph dimension is
@@ -227,6 +230,8 @@ func _draw() -> void:
 			_draw_gas_bomb(center, pulse, s)
 		Icon.GAS_BURNER:
 			_draw_gas_burner_icon(center, pulse, s)
+		Icon.CARRIER_VESSEL:
+			_draw_carrier(center, pulse, s)
 
 
 func _draw_close(center: Vector2, pulse: float, s: float) -> void:
@@ -251,6 +256,20 @@ func _draw_shield_vessel(center: Vector2, pulse: float, s: float) -> void:
 	NeonDraw.draw_glowing_polygon(self, points, _active_color(), pulse, core_color)
 
 
+func _draw_carrier(center: Vector2, pulse: float, s: float) -> void:
+	# Wide and flat-bottomed rather than pointed - reads as a hauler, not a
+	# combat silhouette, matching the ship's own hull_points.
+	var hull := PackedVector2Array([
+		center + Vector2(-13, -4) * s,
+		center + Vector2(-7, -8) * s,
+		center + Vector2(7, -8) * s,
+		center + Vector2(13, -4) * s,
+		center + Vector2(13, 6) * s,
+		center + Vector2(-13, 6) * s,
+	])
+	NeonDraw.draw_glowing_polygon(self, hull, _active_color(), pulse, core_color)
+
+
 func _draw_gas_bomber(center: Vector2, pulse: float, s: float) -> void:
 	var hull := PackedVector2Array([
 		center + Vector2(0, -12) * s,

Main.tscn

@@ -840,8 +840,8 @@ horizontal_alignment = 1
 [node name="AvailableShield" type="Control" parent="UI/HangarMenu"]
 anchor_left = 0.5
 anchor_right = 0.5
-offset_left = -56
+offset_left = -134
-offset_right = 56
+offset_right = -22
 offset_top = 255
 offset_bottom = 375
 script = ExtResource("10")
@@ -852,8 +852,8 @@ glow_color = Color(0.45, 0.8, 1, 1)
 mouse_filter = 2
 anchor_left = 0.5
 anchor_right = 0.5
-offset_left = -96
+offset_left = -174
-offset_right = 96
+offset_right = 18
 offset_top = 380
 offset_bottom = 460
 theme_override_font_sizes/font_size = 22
@@ -862,8 +862,8 @@ horizontal_alignment = 1
 [node name="AvailableGasBomber" type="Control" parent="UI/HangarMenu"]
 anchor_left = 0.5
 anchor_right = 0.5
-offset_left = 178
+offset_left = 22
-offset_right = 290
+offset_right = 134
 offset_top = 255
 offset_bottom = 375
 script = ExtResource("10")
@@ -874,6 +874,28 @@ glow_color = Color(0.96, 0.32, 0.78, 1)
 mouse_filter = 2
 anchor_left = 0.5
 anchor_right = 0.5
+offset_left = -18
+offset_right = 174
+offset_top = 380
+offset_bottom = 460
+theme_override_font_sizes/font_size = 22
+horizontal_alignment = 1
+
+[node name="AvailableCarrier" type="Control" parent="UI/HangarMenu"]
+anchor_left = 0.5
+anchor_right = 0.5
+offset_left = 178
+offset_right = 290
+offset_top = 255
+offset_bottom = 375
+script = ExtResource("10")
+icon = 34
+glow_color = Color(1, 0.78, 0.3, 1)
+
+[node name="AvailableCarrierLabel" type="Label" parent="UI/HangarMenu"]
+mouse_filter = 2
+anchor_left = 0.5
+anchor_right = 0.5
 offset_left = 138
 offset_right = 330
 offset_top = 380
@@ -914,8 +936,8 @@ horizontal_alignment = 1
 [node name="FleetShield" type="Control" parent="UI/HangarMenu"]
 anchor_left = 0.5
 anchor_right = 0.5
-offset_left = -56
+offset_left = -134
-offset_right = 56
+offset_right = -22
 offset_top = 565
 offset_bottom = 685
 script = ExtResource("10")
@@ -926,8 +948,8 @@ glow_color = Color(0.45, 0.8, 1, 1)
 mouse_filter = 2
 anchor_left = 0.5
 anchor_right = 0.5
-offset_left = -96
+offset_left = -174
-offset_right = 96
+offset_right = 18
 offset_top = 690
 offset_bottom = 770
 theme_override_font_sizes/font_size = 22
@@ -936,8 +958,8 @@ horizontal_alignment = 1
 [node name="FleetGasBomber" type="Control" parent="UI/HangarMenu"]
 anchor_left = 0.5
 anchor_right = 0.5
-offset_left = 178
+offset_left = 22
-offset_right = 290
+offset_right = 134
 offset_top = 565
 offset_bottom = 685
 script = ExtResource("10")
@@ -948,6 +970,28 @@ glow_color = Color(0.96, 0.32, 0.78, 1)
 mouse_filter = 2
 anchor_left = 0.5
 anchor_right = 0.5
+offset_left = -18
+offset_right = 174
+offset_top = 690
+offset_bottom = 770
+theme_override_font_sizes/font_size = 22
+horizontal_alignment = 1
+
+[node name="FleetCarrier" type="Control" parent="UI/HangarMenu"]
+anchor_left = 0.5
+anchor_right = 0.5
+offset_left = 178
+offset_right = 290
+offset_top = 565
+offset_bottom = 685
+script = ExtResource("10")
+icon = 34
+glow_color = Color(1, 0.78, 0.3, 1)
+
+[node name="FleetCarrierLabel" type="Label" parent="UI/HangarMenu"]
+mouse_filter = 2
+anchor_left = 0.5
+anchor_right = 0.5
 offset_left = 138
 offset_right = 330
 offset_top = 690
@@ -1000,7 +1044,7 @@ script = ExtResource("24")
 anchor_left = 0.5
 anchor_right = 0.5
 offset_left = -300
-offset_right = -190
+offset_right = -212
 offset_top = 274
 offset_bottom = 394
 script = ExtResource("10")
@@ -1010,8 +1054,8 @@ glow_color = Color(0.25, 0.85, 1, 1)
 [node name="VesselB" type="Control" parent="UI/LabMenu"]
 anchor_left = 0.5
 anchor_right = 0.5
-offset_left = -145
+offset_left = -172
-offset_right = -35
+offset_right = -84
 offset_top = 274
 offset_bottom = 394
 script = ExtResource("10")
@@ -1021,8 +1065,8 @@ glow_color = Color(0.45, 0.8, 1, 1)
 [node name="VesselC" type="Control" parent="UI/LabMenu"]
 anchor_left = 0.5
 anchor_right = 0.5
-offset_left = 35
+offset_left = -44
-offset_right = 145
+offset_right = 44
 offset_top = 274
 offset_bottom = 394
 script = ExtResource("10")
@@ -1032,14 +1076,25 @@ glow_color = Color(0.96, 0.32, 0.78, 1)
 [node name="VesselD" type="Control" parent="UI/LabMenu"]
 anchor_left = 0.5
 anchor_right = 0.5
-offset_left = 190
+offset_left = 84
-offset_right = 300
+offset_right = 172
 offset_top = 274
 offset_bottom = 394
 script = ExtResource("10")
 icon = 12
 glow_color = Color(0.95, 0.55, 0.85, 1)
 
+[node name="VesselE" type="Control" parent="UI/LabMenu"]
+anchor_left = 0.5
+anchor_right = 0.5
+offset_left = 212
+offset_right = 300
+offset_top = 274
+offset_bottom = 394
+script = ExtResource("10")
+icon = 34
+glow_color = Color(1, 0.78, 0.3, 1)
+
 [node name="VesselLabel" type="Label" parent="UI/LabMenu"]
 visible = false
 mouse_filter = 2
@@ -1057,7 +1112,7 @@ mouse_filter = 2
 anchor_left = 0.5
 anchor_right = 0.5
 offset_left = -330
-offset_right = -160
+offset_right = -182
 offset_top = 400
 offset_bottom = 460
 theme_override_font_sizes/font_size = 22
@@ -1068,8 +1123,8 @@ text = "Interceptor"
 mouse_filter = 2
 anchor_left = 0.5
 anchor_right = 0.5
-offset_left = -175
+offset_left = -202
-offset_right = -5
+offset_right = -54
 offset_top = 400
 offset_bottom = 460
 theme_override_font_sizes/font_size = 22
@@ -1080,8 +1135,8 @@ text = "Shield"
 mouse_filter = 2
 anchor_left = 0.5
 anchor_right = 0.5
-offset_left = 5
+offset_left = -74
-offset_right = 175
+offset_right = 74
 offset_top = 400
 offset_bottom = 460
 theme_override_font_sizes/font_size = 22
@@ -1092,14 +1147,26 @@ text = "Gas Bomber"
 mouse_filter = 2
 anchor_left = 0.5
 anchor_right = 0.5
-offset_left = 160
+offset_left = 54
-offset_right = 330
+offset_right = 202
 offset_top = 400
 offset_bottom = 460
 theme_override_font_sizes/font_size = 22
 horizontal_alignment = 1
 text = "Transporter"
 
+[node name="VesselELabel" type="Label" parent="UI/LabMenu"]
+mouse_filter = 2
+anchor_left = 0.5
+anchor_right = 0.5
+offset_left = 182
+offset_right = 330
+offset_top = 400
+offset_bottom = 460
+theme_override_font_sizes/font_size = 22
+horizontal_alignment = 1
+text = "Carrier"
+
 [node name="VesselUpgradeSeparator" type="ColorRect" parent="UI/LabMenu"]
 mouse_filter = 2
 anchor_right = 1.0
@@ -1345,7 +1412,7 @@ anchor_right = 0.5
 anchor_top = 0.5
 anchor_bottom = 0.5
 offset_left = -310
-offset_right = -182
+offset_right = -208
 offset_top = -100
 offset_bottom = 48
 script = ExtResource("10")
@@ -1358,7 +1425,7 @@ anchor_right = 0.5
 anchor_top = 0.5
 anchor_bottom = 0.5
 offset_left = -330
-offset_right = -162
+offset_right = -188
 offset_top = 56
 offset_bottom = 136
 theme_override_font_sizes/font_size = 24
@@ -1370,8 +1437,8 @@ anchor_left = 0.5
 anchor_right = 0.5
 anchor_top = 0.5
 anchor_bottom = 0.5
-offset_left = -148
+offset_left = -174
-offset_right = -20
+offset_right = -72
 offset_top = -100
 offset_bottom = 48
 script = ExtResource("10")
@@ -1384,8 +1451,8 @@ anchor_left = 0.5
 anchor_right = 0.5
 anchor_top = 0.5
 anchor_bottom = 0.5
-offset_left = -168
+offset_left = -194
-offset_right = 0
+offset_right = -52
 offset_top = 56
 offset_bottom = 136
 theme_override_font_sizes/font_size = 24
@@ -1398,8 +1465,8 @@ anchor_left = 0.5
 anchor_right = 0.5
 anchor_top = 0.5
 anchor_bottom = 0.5
-offset_left = 14
+offset_left = -38
-offset_right = 142
+offset_right = 64
 offset_top = -100
 offset_bottom = 28
 script = ExtResource("10")
@@ -1412,8 +1479,8 @@ anchor_left = 0.5
 anchor_right = 0.5
 anchor_top = 0.5
 anchor_bottom = 0.5
-offset_left = -6
+offset_left = -58
-offset_right = 162
+offset_right = 84
 offset_top = 56
 offset_bottom = 150
 theme_override_font_sizes/font_size = 24
@@ -1421,6 +1488,34 @@ autowrap_mode = 2
 text = "Gas Bomber"
 horizontal_alignment = 1
 
+[node name="CarrierButton" type="Control" parent="UI/CraftMenu"]
+anchor_left = 0.5
+anchor_right = 0.5
+anchor_top = 0.5
+anchor_bottom = 0.5
+offset_left = 98
+offset_right = 200
+offset_top = -100
+offset_bottom = 48
+script = ExtResource("10")
+icon = 34
+glow_color = Color(1, 0.78, 0.3, 1)
+
+[node name="CarrierLabel" type="Label" parent="UI/CraftMenu"]
+mouse_filter = 2
+anchor_left = 0.5
+anchor_right = 0.5
+anchor_top = 0.5
+anchor_bottom = 0.5
+offset_left = 78
+offset_right = 220
+offset_top = 56
+offset_bottom = 136
+theme_override_font_sizes/font_size = 24
+autowrap_mode = 2
+text = "Carrier"
+horizontal_alignment = 1
+
 [node name="QueueLabel" type="Label" parent="UI/CraftMenu"]
 mouse_filter = 2
 anchor_left = 1.0

VesselDefinitions.gd

@@ -1,12 +1,13 @@
 class_name VesselDefinitions
 extends RefCounted
 
-const ORDER: PackedStringArray = ["interceptor", "shield", "gas_bomber", "transporter"]
+const ORDER: PackedStringArray = ["interceptor", "shield", "gas_bomber", "transporter", "carrier"]
 const DEFINITIONS: Dictionary = {
 	"interceptor": preload("res://InterceptorVesselDefinition.tres"),
 	"shield": preload("res://ShieldVesselDefinition.tres"),
 	"gas_bomber": preload("res://GasBomberVesselDefinition.tres"),
 	"transporter": preload("res://TransporterVesselDefinition.tres"),
+	"carrier": preload("res://CarrierVesselDefinition.tres"),
 }
 
 static func get_definition(definition_id: String) -> Resource:

tests/_carrier_crafter_preview.gd

@@ -0,0 +1,17 @@
+extends Node2D
+
+# Preview, not a test - #57's crafter menu screenshot with all 4 fleet
+# vessels researched, carrier included as the new 4th entry.
+#
+#   bash tests/screenshot.sh res://tests/_carrier_crafter_preview.tscn /tmp/crafter.png 20 720x1280
+
+
+func _ready() -> void:
+	GameState.buildings.clear()
+	GameState.extractors.clear()
+	GameState.rocks = 500
+	GameState.vessel_levels = {"unlock_shield": 1, "unlock_gas_bomber": 1, "unlock_carrier": 1}
+	var main: Node = load("res://Main.tscn").instantiate()
+	add_child(main)
+	main.get_node("UI/CraftMenu").visible = true
+	main.get_node("BuildController")._refresh_craft_status()

tests/_carrier_crafter_preview.tscn

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

tests/_carrier_hangar_preview.gd

@@ -0,0 +1,21 @@
+extends Node2D
+
+# Preview, not a test - #57's hangar menu screenshot with all 4 fleet
+# vessels researched, one of each stored, and a carrier crewed into the
+# fleet so both rows show the new entry.
+#
+#   bash tests/screenshot.sh res://tests/_carrier_hangar_preview.tscn /tmp/hangar.png 20 720x1280
+
+
+func _ready() -> void:
+	GameState.buildings.clear()
+	GameState.extractors.clear()
+	GameState.rocks = 500
+	GameState.vessel_levels = {"unlock_shield": 1, "unlock_gas_bomber": 1, "unlock_carrier": 1}
+	GameState.stored_vessels = ["shield", "gas_bomber", "carrier"]
+	var main: Node = load("res://Main.tscn").instantiate()
+	add_child(main)
+	var fleet: Node = main.get_node("Fleet")
+	fleet.spawn_ships(2, Vector2.ZERO, PackedStringArray(["interceptor", "carrier"]))
+	main.get_node("UI/HangarMenu").visible = true
+	main.get_node("BuildController")._refresh_hangar()

tests/_carrier_hangar_preview.tscn

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

tests/test_carrier_vessel.gd

@@ -0,0 +1,239 @@
+extends SceneTree
+
+# Headless gameplay test: run with
+#   godot --headless -s res://tests/test_carrier_vessel.gd
+# Forgejo #57: an unarmed hauler that substantially raises how much the
+# fleet can carry (#56).
+#
+# Covers:
+#   A. crewing a carrier raises GameState.fleet_cargo_capacity() by its stat
+#   B. a carrier never fires - no weapon component, no projectile ever
+#      originates from it even with an enemy parked in interceptor fire range
+#   C. it is unbuildable until researched
+#   D. it appears in the crafter, hangar and ship lab with correct name,
+#      cost, icon and colour, and is buildable once researched
+
+var game_state: Node
+var scene: Node
+var fleet: Node
+var controller: Node
+var field: Node
+var crafter_id: int = 0
+var mothership_id: int = 0
+var definition: Resource
+var capacity_before: int = 0
+var enemy: Node
+var stage: int = 0
+var elapsed: float = 0.0
+
+const MOTHERSHIP_AT: Vector2 = Vector2(0.0, 0.0)
+const CRAFTER_AT: Vector2 = Vector2(3000.0, 0.0)
+# Same slot the crafter/hangar UI arrays give carrier: VesselDefinitions.ORDER
+# appends carrier after transporter, and VesselDefinitions.fleet() filters
+# transporter out, so carrier lands last among the 4 fleet-eligible vessels
+# (interceptor, shield, gas_bomber, carrier) in both craft_vessel_* and the
+# hangar_* arrays.
+const FLEET_UI_INDEX: int = 3
+# The ship lab shows every vessel including the transporter, so carrier is
+# the 5th and last slot there.
+const LAB_UI_INDEX: int = 4
+
+
+func _initialize() -> void:
+	game_state = root.get_node("GameState")
+	game_state.buildings.clear()
+	game_state.extractors.clear()
+	game_state.transporters.clear()
+	game_state.stored_vessels.clear()
+	game_state.reset_progression()
+	game_state.build_time_scale = 0.02
+	game_state.rocks = 500
+	scene = load("res://Main.tscn").instantiate()
+	root.add_child(scene)
+	fleet = scene.get_node("Fleet")
+	controller = scene.get_node("BuildController")
+
+
+func _clear_hazards() -> void:
+	for a in get_nodes_in_group("asteroids"):
+		if is_instance_valid(a):
+			a.queue_free()
+	for e in get_nodes_in_group("enemies"):
+		if is_instance_valid(e):
+			e.queue_free()
+
+
+func _process(delta: float) -> bool:
+	elapsed += delta
+	match stage:
+		0:
+			if elapsed < 0.2:
+				return false
+			scene.get_node("AsteroidField").set_process(false)
+			scene.get_node("EnemySpawner").set_process(false)
+			_clear_hazards()
+
+			# --- structural: unarmed, cargo-capable, fleet-eligible ---------
+			definition = game_state.vessel_definition(GameState.VESSEL_CARRIER)
+			if definition == null or not definition.fleet_eligible:
+				return _fail("carrier is not a fleet-eligible vessel definition")
+			if definition.capabilities.has("weapon"):
+				return _fail("carrier declares a weapon capability")
+			if not definition.capabilities.has("cargo"):
+				return _fail("carrier does not declare the cargo capability")
+
+			# --- A. capacity math, directly -----------------------------------
+			if game_state.fleet_cargo_capacity(PackedStringArray(["carrier"])) != 120:
+				return _fail("one carrier's capacity contribution is %d, expected 120" \
+					% game_state.fleet_cargo_capacity(PackedStringArray(["carrier"])))
+			print("structural: unarmed, cargo capability, contributes 120 alone")
+
+			# --- C. gated until researched --------------------------------
+			field = scene.get_node("BuildingField")
+			field.place(GameState.BUILDING_MOTHERSHIP, MOTHERSHIP_AT)
+			mothership_id = int(game_state.buildings[-1].id)
+			field.place(GameState.BUILDING_SHIP_CRAFTER, CRAFTER_AT)
+			crafter_id = int(game_state.buildings[-1].id)
+			field.place(GameState.BUILDING_SHIP_LAB, CRAFTER_AT + Vector2(0.0, 400.0))
+			if game_state.vessel_is_unlocked(GameState.VESSEL_CARRIER):
+				return _fail("carrier starts unlocked")
+			if game_state.queue_order(crafter_id, GameState.VESSEL_CARRIER):
+				return _fail("queue_order accepted an unresearched carrier")
+			print("unresearched carrier is unbuildable, as expected")
+
+			# --- D. locked state in the crafter UI -------------------------
+			controller.craft_building_id = crafter_id
+			controller._refresh_craft_status()
+			if controller.craft_vessel_buttons[FLEET_UI_INDEX].enabled:
+				return _fail("a locked carrier shows enabled in the crafter menu")
+
+			stage = 1
+			elapsed = 0.0
+			return false
+		1:
+			if elapsed < 0.1:
+				return false
+			# --- C continued: unlocking ------------------------------------
+			if not game_state.unlock_vessel(GameState.VESSEL_CARRIER):
+				return _fail("unlock_vessel(carrier) failed with 500 ore in the bank")
+			if not game_state.vessel_is_unlocked(GameState.VESSEL_CARRIER):
+				return _fail("carrier still reports locked after unlocking")
+			if game_state.product_costs(GameState.VESSEL_CARRIER) != {GameState.RESOURCE_ORE: 24}:
+				return _fail("carrier's build cost is %s, expected 24 ore" \
+					% game_state.product_costs(GameState.VESSEL_CARRIER))
+			print("researched: unlocked, costs %s" % game_state.product_costs(GameState.VESSEL_CARRIER))
+
+			# --- D. unlocked state in the crafter UI ------------------------
+			controller._refresh_craft_status()
+			var craft_button: IconButton = controller.craft_vessel_buttons[FLEET_UI_INDEX]
+			var craft_label: Label = controller.craft_vessel_labels[FLEET_UI_INDEX]
+			if not craft_button.enabled:
+				return _fail("an unlocked carrier still shows disabled in the crafter menu")
+			if craft_button.icon != definition.icon or craft_button.glow_color != definition.glow_color:
+				return _fail("crafter carrier button does not match its definition's icon/colour")
+			if not craft_label.text.begins_with(definition.display_name):
+				return _fail("crafter carrier label reads '%s', expected to start with '%s'" \
+					% [craft_label.text, definition.display_name])
+			if not game_state.queue_order(crafter_id, GameState.VESSEL_CARRIER):
+				return _fail("queue_order rejected a researched carrier")
+			print("crafter: enabled, correct icon/colour, correct label, buildable")
+
+			# Bypass the build timer/delivery wait - that queue mechanism is
+			# generic and already covered for every other vessel
+			# (test_building_stock_queue.gd, test_resources_and_buildings.gd
+			# etc.); this ticket is about the carrier's OWN behaviour, not
+			# re-proving crafting works.
+			game_state.stored_vessels.append(GameState.VESSEL_CARRIER)
+
+			# --- D. hangar display -------------------------------------------
+			controller._refresh_hangar()
+			var available_slot: IconButton = controller.hangar_available_slots[FLEET_UI_INDEX]
+			var available_label: Label = controller.hangar_available_labels[FLEET_UI_INDEX]
+			if available_slot.icon != definition.icon or available_slot.glow_color != definition.glow_color:
+				return _fail("hangar carrier slot does not match its definition's icon/colour")
+			var expected_available: String = "%s\n1 available" % definition.display_name
+			if available_label.text != expected_available:
+				return _fail("hangar carrier label reads '%s', expected '%s'" \
+					% [available_label.text, expected_available])
+			print("hangar: correct icon/colour, shows 1 available")
+
+			# --- A continued: crewing it raises capacity ---------------------
+			# The default fleet (5 interceptors) already sits at
+			# max_fleet_size() with reset_progression()'s cleared skills, which
+			# would make _on_hangar_crew_type refuse for being full - shrink
+			# to 1 ship first so there is room to crew the carrier at all.
+			fleet.spawn_ships(1, MOTHERSHIP_AT, PackedStringArray([GameState.VESSEL_INTERCEPTOR]))
+			capacity_before = game_state.fleet_cargo_total_capacity()
+			controller._on_hangar_crew_type(FLEET_UI_INDEX)
+			if not fleet.has_vessel_type(GameState.VESSEL_CARRIER):
+				return _fail("crewing from the hangar did not add a carrier to the fleet")
+			var capacity_after: int = game_state.fleet_cargo_total_capacity()
+			if capacity_after != capacity_before + 120:
+				return _fail("crewing a carrier moved capacity %d -> %d, expected +120" \
+					% [capacity_before, capacity_after])
+			print("crewed: capacity %d -> %d (+120)" % [capacity_before, capacity_after])
+
+			# --- D. ship lab display -------------------------------------------
+			controller.lab_vessel = GameState.VESSEL_CARRIER
+			controller._refresh_lab()
+			var lab_button: IconButton = controller.lab_vessel_buttons[LAB_UI_INDEX]
+			var lab_label: Label = controller.lab_vessel_labels[LAB_UI_INDEX]
+			if lab_button.icon != definition.icon or lab_button.glow_color != definition.glow_color:
+				return _fail("ship lab carrier slot does not match its definition's icon/colour")
+			if lab_label.text != definition.display_name:
+				return _fail("ship lab carrier label reads '%s', expected '%s'" \
+					% [lab_label.text, definition.display_name])
+			print("ship lab: correct icon/colour/label")
+
+			stage = 2
+			elapsed = 0.0
+			return false
+		2:
+			# --- B. never fires, even with a target in range -----------------
+			# Isolate: JUST a carrier in the fleet, nothing else nearby that
+			# could fire instead and make the check meaningless.
+			fleet.spawn_ships(1, Vector2.ZERO, PackedStringArray([GameState.VESSEL_CARRIER]))
+			stage = 3
+			elapsed = 0.0
+			return false
+		3:
+			# A settling tick before the enemy appears: queue_free() on the
+			# ships spawn_ships() just replaced does not remove them from the
+			# tree instantly, so a stale interceptor's weapon could otherwise
+			# still get one last physics tick against a target added in the
+			# same frame - a false positive, not the carrier firing.
+			if elapsed < 0.3:
+				return false
+			var enemy_scene: PackedScene = load("res://Enemy.tscn")
+			enemy = enemy_scene.instantiate()
+			enemy.position = fleet.get_centroid() + Vector2(220.0, 0.0)
+			scene.add_child(enemy)
+			# Frozen in place: a chaser closes distance and kills on contact,
+			# and an unarmed carrier has nothing to stop that. Letting it
+			# approach would wipe the fleet, trip the "rebuild at the
+			# mothership" safety net (a default INTERCEPTOR), and that
+			# interceptor firing would look like a carrier-firing false
+			# positive - this test is about whether the carrier fires, not
+			# whether it can survive unescorted.
+			enemy.set_physics_process(false)
+			stage = 4
+			elapsed = 0.0
+			return false
+		4:
+			if elapsed < 2.0:
+				return false
+			var projectiles: Array = get_nodes_in_group("player_projectiles")
+			if not projectiles.is_empty():
+				return _fail("%d projectile(s) originated from a fleet made only of a carrier" \
+					% projectiles.size())
+			print("no projectiles after %.1fs with an enemy in interceptor fire range" % elapsed)
+			print("TEST_CARRIER_VESSEL: PASS")
+			quit(0)
+			return true
+	return false
+
+
+func _fail(message: String) -> bool:
+	print("TEST_CARRIER_VESSEL: FAIL (%s)" % message)
+	quit(1)
+	return true

tests/test_vessel_composition.gd

@@ -23,7 +23,7 @@ func _process(delta: float) -> bool:
 		return false
 	var definitions: Array = VESSEL_DEFINITIONS.all()
 	var fleet_definitions: Array = VESSEL_DEFINITIONS.fleet()
-	if fleet_definitions.size() != 3 \
+	if fleet_definitions.size() != 4 \
 			or fleet_definitions.any(func(definition): return definition.has_capability("transport")):
 		return _fail("logistics transporters leaked into the combat-fleet catalog")
 	if ships.size() != definitions.size():