Prohibit world modification during configuration stage.

Quillraven · Nov 30, 2023 · 782b8df · 782b8df
1 parent 1544ecc
commit 782b8df
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Showing 4 changed files with 33 additions and 3 deletions.
diff --git a/src/commonMain/kotlin/com/github/quillraven/fleks/exception.kt b/src/commonMain/kotlin/com/github/quillraven/fleks/exception.kt
@@ -38,3 +38,6 @@ class FleksWrongConfigurationUsageException :
 
 class FleksWrongSystemInterfaceException(system: KClass<*>, `interface`: KClass<*>) :
     FleksException("System ${system.simpleName} cannot have interface ${`interface`.simpleName}")
+
+class FleksWorldModificationDuringConfigurationException :
+    FleksException("Entities were added during world configuration.")
diff --git a/src/commonMain/kotlin/com/github/quillraven/fleks/world.kt b/src/commonMain/kotlin/com/github/quillraven/fleks/world.kt
@@ -178,6 +178,10 @@ class WorldConfiguration(@PublishedApi internal val world: World) {
             world.systems = it.systems.toTypedArray()
         }
 
+        if (world.numEntities > 0) {
+            throw FleksWorldModificationDuringConfigurationException()
+        }
+
         setUpAggregatedFamilyHooks()
 
         world.systems.forEach { it.onInit() }

diff --git a/src/commonTest/kotlin/com/github/quillraven/fleks/SystemTest.kt b/src/commonTest/kotlin/com/github/quillraven/fleks/SystemTest.kt
@@ -78,7 +78,8 @@ private class SystemTestIteratingSystem : IteratingSystem(
 private class SystemTestEntityCreation : IteratingSystem(family { any(SystemTestComponent) }) {
     var numTicks = 0
 
-    init {
+    override fun onInit() {
+        super.onInit()
         world.entity { it += SystemTestComponent() }
     }
 
@@ -176,6 +177,15 @@ private class SystemTestEnable(enabled: Boolean) : IntervalSystem(enabled = enab
     override fun onTick() = Unit
 }
 
+private class AddEntityInConstructorSystem() : IntervalSystem() {
+
+    init {
+        world.entity { }
+    }
+
+    override fun onTick() = Unit
+}
+
 internal class SystemTest {
     @Test
     fun systemWithIntervalEachFrameGetsCalledEveryTime() {
@@ -499,4 +509,15 @@ internal class SystemTest {
         assertFalse(system.enabledCall)
         assertFalse(system.disabledCall)
     }
+
+    @Test
+    fun testWorldModificationDuringConfiguration() {
+        assertFailsWith<FleksWorldModificationDuringConfigurationException> {
+            configureWorld {
+                systems {
+                    add(AddEntityInConstructorSystem())
+                }
+            }
+        }
+    }
 }
diff --git a/src/commonTest/kotlin/com/github/quillraven/fleks/WorldTest.kt b/src/commonTest/kotlin/com/github/quillraven/fleks/WorldTest.kt
@@ -66,7 +66,8 @@ private class WorldTestIteratingSystem(
 }
 
 private class WorldTestInitSystem : IteratingSystem(family { all(WorldTestComponent) }) {
-    init {
+    override fun onInit() {
+        super.onInit()
         world.entity { it += WorldTestComponent() }
     }
 
@@ -76,7 +77,8 @@ private class WorldTestInitSystem : IteratingSystem(family { all(WorldTestCompon
 private class WorldTestInitSystemExtraFamily : IteratingSystem(family { all(WorldTestComponent) }) {
     val extraFamily = world.family { any(WorldTestComponent2).none(WorldTestComponent) }
 
-    init {
+    override fun onInit() {
+        super.onInit()
         world.entity { it += WorldTestComponent2() }
     }