Improvements to several observables and more unit tests.

FEATURES.md

@@ -157,6 +157,16 @@ Features that are in ***bold italics*** are planned but not yet implemented.
 
 - ***Support different sets of instructions (older versions had no stack)***
 
+## Verification/Warnings
+
+- ***Entities with nonexistent event section***
+- ***Entities with wave that's never triggered***
+- ***Duplicate event IDs***
+- ***Events with nonexistent event section***
+- ***Event waves with no enemies***
+- ***Events that trigger nonexistent events***
+- ***Events that lock/unlock nonexistent doors***
+
 ## Bugs
 
 - When a modal dialog is open, global keybindings should be disabled

observable/src/commonMain/kotlin/world/phantasmal/observable/cell/list/AbstractDependentListCell.kt

@@ -1,13 +1,13 @@
 package world.phantasmal.observable.cell.list
 
 import world.phantasmal.core.disposable.Disposable
+import world.phantasmal.core.unsafe.unsafeAssertNotNull
 import world.phantasmal.observable.CallbackObserver
 import world.phantasmal.observable.Dependent
 import world.phantasmal.observable.Observer
 import world.phantasmal.observable.cell.AbstractDependentCell
 import world.phantasmal.observable.cell.Cell
 import world.phantasmal.observable.cell.DependentCell
-import world.phantasmal.observable.cell.not
 
 abstract class AbstractDependentListCell<E> :
     AbstractDependentCell<List<E>>(),
@@ -25,12 +25,35 @@ abstract class AbstractDependentListCell<E> :
             return elements
         }
 
-    @Suppress("LeakingThis")
-    final override val size: Cell<Int> = DependentCell(this) { elements.size }
+    private var _size: Cell<Int>? = null
+    final override val size: Cell<Int>
+        get() {
+            if (_size == null) {
+                _size = DependentCell(this) { value.size }
+            }
 
-    final override val empty: Cell<Boolean> = size.map { it == 0 }
+            return unsafeAssertNotNull(_size)
+        }
 
-    final override val notEmpty: Cell<Boolean> = !empty
+    private var _empty: Cell<Boolean>? = null
+    final override val empty: Cell<Boolean>
+        get() {
+            if (_empty == null) {
+                _empty = DependentCell(this) { value.isEmpty() }
+            }
+
+            return unsafeAssertNotNull(_empty)
+        }
+
+    private var _notEmpty: Cell<Boolean>? = null
+    final override val notEmpty: Cell<Boolean>
+        get() {
+            if (_notEmpty == null) {
+                _notEmpty = DependentCell(this) { value.isNotEmpty() }
+            }
+
+            return unsafeAssertNotNull(_notEmpty)
+        }
 
     final override fun observe(callNow: Boolean, observer: Observer<List<E>>): Disposable =
         observeList(callNow, observer as ListObserver<E>)

observable/src/commonMain/kotlin/world/phantasmal/observable/cell/list/FilteredListCell.kt

@@ -14,7 +14,7 @@ class FilteredListCell<E>(
      */
     private val indexMap = mutableListOf<Int>()
 
-    private var elements: ListWrapper<E> = ListWrapper(mutableListOf())
+    private val elements = mutableListOf<E>()
 
     override val value: List<E>
         get() {
@@ -125,7 +125,7 @@ class FilteredListCell<E>(
                                     }
                                 }
 
-                                elements = elements.mutate { add(insertIndex, change.updated) }
+                                elements.add(insertIndex, change.updated)
                                 indexMap[change.index] = insertIndex
 
                                 for (depIdx in (change.index + 1)..indexMap.lastIndex) {
@@ -151,7 +151,7 @@ class FilteredListCell<E>(
                             if (index != -1) {
                                 // If the element now doesn't pass the test and it previously did
                                 // pass, remove it and emit a structural change.
-                                elements = elements.mutate { removeAt(index) }
+                                elements.removeAt(index)
                                 indexMap[change.index] = -1
 
                                 for (depIdx in (change.index + 1)..indexMap.lastIndex) {
@@ -195,18 +195,16 @@ class FilteredListCell<E>(
     }
 
     private fun recompute() {
-        val newElements = mutableListOf<E>()
+        elements.clear()
         indexMap.clear()
 
         dependency.value.forEach { element ->
             if (predicate(element)) {
-                newElements.add(element)
-                indexMap.add(newElements.lastIndex)
+                elements.add(element)
+                indexMap.add(elements.lastIndex)
             } else {
                 indexMap.add(-1)
             }
         }
-
-        elements = ListWrapper(newElements)
     }
 }

observable/src/commonMain/kotlin/world/phantasmal/observable/cell/list/ListCellCreation.kt

@@ -14,6 +14,11 @@ fun <E> mutableListCell(
 ): MutableListCell<E> =
     SimpleListCell(mutableListOf(*elements), extractDependencies)
 
+fun <T, R> Cell<T>.flatMapToList(
+    transform: (T) -> ListCell<R>,
+): ListCell<R> =
+    FlatteningDependentListCell(this) { transform(value) }
+
 fun <T1, T2, R> flatMapToList(
     c1: Cell<T1>,
     c2: Cell<T2>,

observable/src/commonMain/kotlin/world/phantasmal/observable/cell/list/ListWrapper.kt

@@ -1,30 +0,0 @@
-package world.phantasmal.observable.cell.list
-
-import kotlin.contracts.InvocationKind
-import kotlin.contracts.contract
-
-/**
- * ListWrapper is used to ensure that ListCell.value of some implementations references a new object
- * after every change to the ListCell. This is done to honor the contract that emission of a
- * ChangeEvent implies that Cell.value is no longer equal to the previous value.
- * When a change is made to the ListCell, the underlying list of ListWrapper is usually mutated and
- * then a new wrapper is created that points to the same underlying list.
- */
-internal class ListWrapper<E>(private val mut: MutableList<E>) : List<E> by mut {
-    inline fun mutate(mutator: MutableList<E>.() -> Unit): ListWrapper<E> {
-        contract { callsInPlace(mutator, InvocationKind.EXACTLY_ONCE) }
-        mut.mutator()
-        return ListWrapper(mut)
-    }
-
-    override fun equals(other: Any?): Boolean {
-        if (this === other) return true
-        // If other is also a ListWrapper but it's not the exact same object then it's not equal.
-        if (other == null || this::class == other::class || other !is List<*>) return false
-        // If other is a list but not a ListWrapper, call its equals method for a structured
-        // comparison.
-        return other == this
-    }
-
-    override fun hashCode(): Int = mut.hashCode()
-}

observable/src/commonMain/kotlin/world/phantasmal/observable/cell/list/SimpleListCell.kt

@@ -1,11 +1,12 @@
 package world.phantasmal.observable.cell.list
 
 import world.phantasmal.core.disposable.Disposable
+import world.phantasmal.core.replaceAll
 import world.phantasmal.core.unsafe.unsafeAssertNotNull
 import world.phantasmal.observable.ChangeEvent
+import world.phantasmal.observable.ChangeManager
 import world.phantasmal.observable.Dependency
 import world.phantasmal.observable.Dependent
-import world.phantasmal.observable.ChangeManager
 
 typealias DependenciesExtractor<E> = (element: E) -> Array<Dependency>
 
@@ -16,12 +17,10 @@ typealias DependenciesExtractor<E> = (element: E) -> Array<Dependency>
  * event.
  */
 class SimpleListCell<E>(
-    elements: MutableList<E>,
+    private val elements: MutableList<E>,
     private val extractDependencies: DependenciesExtractor<E>? = null,
 ) : AbstractListCell<E>(), MutableListCell<E> {
 
-    private var elements = ListWrapper(elements)
-
     /**
      * Dependents of dependencies related to this list's elements. Allows us to propagate changes to
      * elements via [ListChangeEvent]s.
@@ -43,10 +42,9 @@ class SimpleListCell<E>(
         checkIndex(index, elements.lastIndex)
         emitMightChange()
 
-        val removed: E
-        elements = elements.mutate { removed = set(index, element) }
+        val removed = elements.set(index, element)
 
-        if (extractDependencies != null) {
+        if (dependents.isNotEmpty() && extractDependencies != null) {
             elementDependents[index].dispose()
             elementDependents[index] = ElementDependent(index, element)
         }
@@ -61,7 +59,7 @@ class SimpleListCell<E>(
         emitMightChange()
 
         val index = elements.size
-        elements = elements.mutate { add(index, element) }
+        elements.add(element)
 
         finalizeStructuralChange(index, emptyList(), listOf(element))
     }
@@ -70,7 +68,7 @@ class SimpleListCell<E>(
         checkIndex(index, elements.size)
         emitMightChange()
 
-        elements = elements.mutate { add(index, element) }
+        elements.add(index, element)
 
         finalizeStructuralChange(index, emptyList(), listOf(element))
     }
@@ -90,8 +88,7 @@ class SimpleListCell<E>(
         checkIndex(index, elements.lastIndex)
         emitMightChange()
 
-        val removed: E
-        elements = elements.mutate { removed = removeAt(index) }
+        val removed = elements.removeAt(index)
 
         finalizeStructuralChange(index, listOf(removed), emptyList())
         return removed
@@ -100,30 +97,32 @@ class SimpleListCell<E>(
     override fun replaceAll(elements: Iterable<E>) {
         emitMightChange()
 
-        val removed = this.elements
-        this.elements = ListWrapper(elements.toMutableList())
+        val removed = ArrayList(this.elements)
+        this.elements.replaceAll(elements)
 
-        finalizeStructuralChange(0, removed, this.elements)
+        finalizeStructuralChange(0, removed, ArrayList(this.elements))
     }
 
     override fun replaceAll(elements: Sequence<E>) {
         emitMightChange()
 
-        val removed = this.elements
-        this.elements = ListWrapper(elements.toMutableList())
+        val removed = ArrayList(this.elements)
+        this.elements.replaceAll(elements)
 
-        finalizeStructuralChange(0, removed, this.elements)
+        finalizeStructuralChange(0, removed, ArrayList(this.elements))
     }
 
     override fun splice(fromIndex: Int, removeCount: Int, newElement: E) {
-        val removed = ArrayList(elements.subList(fromIndex, fromIndex + removeCount))
+        val removed = ArrayList<E>(removeCount)
+
+        for (i in fromIndex until (fromIndex + removeCount)) {
+            removed.add(elements[i])
+        }
 
         emitMightChange()
 
-        elements = elements.mutate {
-            repeat(removeCount) { removeAt(fromIndex) }
-            add(fromIndex, newElement)
-        }
+        repeat(removeCount) { elements.removeAt(fromIndex) }
+        elements.add(fromIndex, newElement)
 
         finalizeStructuralChange(fromIndex, removed, listOf(newElement))
     }
@@ -131,8 +130,8 @@ class SimpleListCell<E>(
     override fun clear() {
         emitMightChange()
 
-        val removed = elements
-        elements = ListWrapper(mutableListOf())
+        val removed = ArrayList(this.elements)
+        elements.clear()
 
         finalizeStructuralChange(0, removed, emptyList())
     }
@@ -140,15 +139,16 @@ class SimpleListCell<E>(
     override fun sortWith(comparator: Comparator<E>) {
         emitMightChange()
 
+        val removed = ArrayList(elements)
         var throwable: Throwable? = null
 
         try {
-            elements = elements.mutate { sortWith(comparator) }
+            elements.sortWith(comparator)
         } catch (e: Throwable) {
             throwable = e
         }
 
-        finalizeStructuralChange(0, elements, elements)
+        finalizeStructuralChange(0, removed, ArrayList(elements))
 
         if (throwable != null) {
             throw throwable
@@ -178,11 +178,9 @@ class SimpleListCell<E>(
     }
 
     override fun emitDependencyChanged() {
-        try {
-            emitDependencyChanged(ListChangeEvent(elements, changes))
-        } finally {
+        val currentChanges = changes
         changes = mutableListOf()
-        }
+        emitDependencyChanged(ListChangeEvent(elements, currentChanges))
     }
 
     private fun checkIndex(index: Int, maxIndex: Int) {
@@ -194,7 +192,7 @@ class SimpleListCell<E>(
     }
 
     private fun finalizeStructuralChange(index: Int, removed: List<E>, inserted: List<E>) {
-        if (extractDependencies != null) {
+        if (dependents.isNotEmpty() && extractDependencies != null) {
             repeat(removed.size) {
                 elementDependents.removeAt(index).dispose()
             }

observable/src/commonTest/kotlin/world/phantasmal/observable/DependencyTests.kt

@@ -0,0 +1,47 @@
+package world.phantasmal.observable
+
+import world.phantasmal.observable.test.ObservableTestSuite
+import kotlin.test.*
+
+interface DependencyTests : ObservableTestSuite {
+    fun createProvider(): Provider
+
+    @Test
+    fun correctly_emits_changes_to_its_dependents() = test {
+        val p = createProvider()
+        var dependencyMightChangeCalled = false
+        var dependencyChangedCalled = false
+
+        p.dependency.addDependent(object : Dependent {
+            override fun dependencyMightChange() {
+                assertFalse(dependencyMightChangeCalled)
+                assertFalse(dependencyChangedCalled)
+                dependencyMightChangeCalled = true
+            }
+
+            override fun dependencyChanged(dependency: Dependency, event: ChangeEvent<*>?) {
+                assertTrue(dependencyMightChangeCalled)
+                assertFalse(dependencyChangedCalled)
+                assertEquals(p.dependency, dependency)
+                assertNotNull(event)
+                dependencyChangedCalled = true
+            }
+        })
+
+        repeat(5) { index ->
+            dependencyMightChangeCalled = false
+            dependencyChangedCalled = false
+
+            p.emit()
+
+            assertTrue(dependencyMightChangeCalled, "repetition $index")
+            assertTrue(dependencyChangedCalled, "repetition $index")
+        }
+    }
+
+    interface Provider {
+        val dependency: Dependency
+
+        fun emit()
+    }
+}

observable/src/commonTest/kotlin/world/phantasmal/observable/ObservableTests.kt

@@ -1,6 +1,5 @@
 package world.phantasmal.observable
 
-import world.phantasmal.observable.test.ObservableTestSuite
 import kotlin.test.Test
 import kotlin.test.assertEquals
 
@@ -8,8 +7,8 @@ import kotlin.test.assertEquals
  * Test suite for all [Observable] implementations. There is a subclass of this suite for every
  * [Observable] implementation.
  */
-interface ObservableTests : ObservableTestSuite {
-    fun createProvider(): Provider
+interface ObservableTests : DependencyTests {
+    override fun createProvider(): Provider
 
     @Test
     fun calls_observers_when_events_are_emitted() = test {
@@ -55,9 +54,9 @@ interface ObservableTests : ObservableTestSuite {
         assertEquals(1, changes)
     }
 
-    interface Provider {
+    interface Provider : DependencyTests.Provider {
         val observable: Observable<*>
 
-        fun emit()
+        override val dependency: Dependency get() = observable
     }
 }

observable/src/commonTest/kotlin/world/phantasmal/observable/cell/DependentCellTests.kt

@@ -9,12 +9,12 @@ class DependentCellTests : RegularCellTests, CellWithDependenciesTests {
     }
 
     class Provider : CellTests.Provider, CellWithDependenciesTests.Provider {
-        private val dependency = SimpleCell(1)
+        private val dependencyCell = SimpleCell(1)
 
-        override val observable = DependentCell(dependency) { 2 * dependency.value }
+        override val observable = DependentCell(dependencyCell) { 2 * dependencyCell.value }
 
         override fun emit() {
-            dependency.value += 2
+            dependencyCell.value += 2
         }
 
         override fun createWithDependencies(vararg dependencies: Cell<Int>) =

observable/src/commonTest/kotlin/world/phantasmal/observable/cell/list/DependentListCellTests.kt

@@ -9,12 +9,14 @@ class DependentListCellTests : ListCellTests, CellWithDependenciesTests {
     override fun createListProvider(empty: Boolean) = Provider(empty)
 
     class Provider(empty: Boolean) : ListCellTests.Provider, CellWithDependenciesTests.Provider {
-        private val dependency = SimpleListCell(if (empty) mutableListOf() else mutableListOf(5))
+        private val dependencyCell =
+            SimpleListCell(if (empty) mutableListOf() else mutableListOf(5))
 
-        override val observable = DependentListCell(dependency) { dependency.value.map { 2 * it } }
+        override val observable =
+            DependentListCell(dependencyCell) { dependencyCell.value.map { 2 * it } }
 
         override fun addElement() {
-            dependency.add(4)
+            dependencyCell.add(4)
         }
 
         override fun createWithDependencies(vararg dependencies: Cell<Int>): Cell<Any> =

observable/src/commonTest/kotlin/world/phantasmal/observable/cell/list/FilteredListCellTests.kt

@@ -5,13 +5,13 @@ import kotlin.test.*
 
 class FilteredListCellTests : ListCellTests {
     override fun createListProvider(empty: Boolean) = object : ListCellTests.Provider {
-        private val dependency =
+        private val dependencyCell =
             SimpleListCell(if (empty) mutableListOf(5) else mutableListOf(5, 10))
 
-        override val observable = FilteredListCell(dependency, predicate = { it % 2 == 0 })
+        override val observable = FilteredListCell(dependencyCell, predicate = { it % 2 == 0 })
 
         override fun addElement() {
-            dependency.add(4)
+            dependencyCell.add(4)
         }
     }
 

observable/src/commonTest/kotlin/world/phantasmal/observable/cell/list/FlatteningDependentListCellDirectDependencyEmitsTests.kt

@@ -11,15 +11,15 @@ class FlatteningDependentListCellDirectDependencyEmitsTests : ListCellTests {
         private val transitiveDependency = StaticListCell(if (empty) emptyList() else listOf(7))
 
         // The direct dependency of the list under test can change.
-        private val dependency = SimpleCell<ListCell<Int>>(transitiveDependency)
+        private val directDependency = SimpleCell<ListCell<Int>>(transitiveDependency)
 
         override val observable =
-            FlatteningDependentListCell(dependency) { dependency.value }
+            FlatteningDependentListCell(directDependency) { directDependency.value }
 
         override fun addElement() {
             // Update the direct dependency.
-            val oldTransitiveDependency: ListCell<Int> = dependency.value
-            dependency.value = StaticListCell(oldTransitiveDependency.value + 4)
+            val oldTransitiveDependency: ListCell<Int> = directDependency.value
+            directDependency.value = StaticListCell(oldTransitiveDependency.value + 4)
         }
     }
 }

observable/src/commonTest/kotlin/world/phantasmal/observable/cell/list/FlatteningDependentListCellTransitiveDependencyEmitsTests.kt

@@ -21,10 +21,10 @@ class FlatteningDependentListCellTransitiveDependencyEmitsTests :
             SimpleListCell(if (empty) mutableListOf() else mutableListOf(7))
 
         // The direct dependency of the list under test can't change.
-        private val dependency = StaticCell<ListCell<Int>>(transitiveDependency)
+        private val directDependency = StaticCell<ListCell<Int>>(transitiveDependency)
 
         override val observable =
-            FlatteningDependentListCell(dependency) { dependency.value }
+            FlatteningDependentListCell(directDependency) { directDependency.value }
 
         override fun addElement() {
             // Update the transitive dependency.

observable/src/commonTest/kotlin/world/phantasmal/observable/cell/list/ListCellCreationTests.kt

@@ -0,0 +1,17 @@
+package world.phantasmal.observable.cell.list
+
+import world.phantasmal.observable.cell.SimpleCell
+import world.phantasmal.observable.test.ObservableTestSuite
+import world.phantasmal.observable.test.assertListCellEquals
+import kotlin.test.Test
+
+class ListCellCreationTests : ObservableTestSuite {
+    @Test
+    fun test_flatMapToList() = test {
+        val cell = SimpleCell(SimpleListCell(mutableListOf(1, 2, 3, 4, 5)))
+
+        val mapped = cell.flatMapToList { it }
+
+        assertListCellEquals(listOf(1, 2, 3, 4, 5), mapped)
+    }
+}

observable/src/commonTest/kotlin/world/phantasmal/observable/cell/list/SimpleListCellTests.kt

@@ -1,6 +1,7 @@
 package world.phantasmal.observable.cell.list
 
 import world.phantasmal.observable.cell.SimpleCell
+import world.phantasmal.observable.test.assertListCellEquals
 import world.phantasmal.testUtils.TestContext
 import kotlin.test.*
 
@@ -25,11 +26,30 @@ class SimpleListCellTests : MutableListCellTests<Int> {
     fun instantiates_correctly() = test {
         val list = SimpleListCell(mutableListOf(1, 2, 3))
 
-        assertEquals(3, list.size.value)
-        assertEquals(3, list.value.size)
-        assertEquals(1, list[0])
-        assertEquals(2, list[1])
-        assertEquals(3, list[2])
+        assertListCellEquals(listOf(1, 2, 3), list)
+    }
+
+    @Test
+    fun set() = test {
+        testSet(SimpleListCell(mutableListOf("a", "b", "c")))
+    }
+
+    @Test
+    fun set_with_extractDependencies() = test {
+        testSet(SimpleListCell(mutableListOf("a", "b", "c")) { arrayOf() })
+    }
+
+    private fun testSet(list: SimpleListCell<String>) {
+        list[1] = "test"
+        list[2] = "test2"
+        assertFailsWith<IndexOutOfBoundsException> {
+            list[-1] = "should not be in list"
+        }
+        assertFailsWith<IndexOutOfBoundsException> {
+            list[3] = "should not be in list"
+        }
+
+        assertListCellEquals(listOf("a", "test", "test2"), list)
     }
 
     @Test
@@ -40,10 +60,92 @@ class SimpleListCellTests : MutableListCellTests<Int> {
         list.add(1, "c")
         list.add(0, "a")
 
-        assertEquals(3, list.size.value)
-        assertEquals("a", list[0])
-        assertEquals("b", list[1])
-        assertEquals("c", list[2])
+        assertListCellEquals(listOf("a", "b", "c"), list)
+    }
+
+    @Test
+    fun remove() = test {
+        val list = SimpleListCell(mutableListOf("a", "b", "c", "d", "e"))
+
+        assertTrue(list.remove("c"))
+
+        assertListCellEquals(listOf("a", "b", "d", "e"), list)
+
+        assertTrue(list.remove("a"))
+
+        assertListCellEquals(listOf("b", "d", "e"), list)
+
+        assertTrue(list.remove("e"))
+
+        assertListCellEquals(listOf("b", "d"), list)
+
+        // The following values are not in the list (anymore).
+        assertFalse(list.remove("x"))
+        assertFalse(list.remove("a"))
+        assertFalse(list.remove("c"))
+
+        // List should remain unchanged after removal attempts of nonexistent elements.
+        assertListCellEquals(listOf("b", "d"), list)
+    }
+
+    @Test
+    fun removeAt() = test {
+        val list = SimpleListCell(mutableListOf("a", "b", "c", "d", "e"))
+
+        list.removeAt(2)
+
+        assertListCellEquals(listOf("a", "b", "d", "e"), list)
+
+        list.removeAt(0)
+
+        assertListCellEquals(listOf("b", "d", "e"), list)
+
+        list.removeAt(2)
+
+        assertListCellEquals(listOf("b", "d"), list)
+
+        assertFailsWith<IndexOutOfBoundsException> {
+            list.removeAt(-1)
+        }
+        assertFailsWith<IndexOutOfBoundsException> {
+            list.removeAt(list.size.value)
+        }
+
+        // List should remain unchanged after invalid calls.
+        assertListCellEquals(listOf("b", "d"), list)
+    }
+
+    @Test
+    fun splice() = test {
+        val list = SimpleListCell((0..9).toMutableList())
+
+        list.splice(fromIndex = 3, removeCount = 5, newElement = 100)
+
+        assertListCellEquals(listOf(0, 1, 2, 100, 8, 9), list)
+
+        list.splice(fromIndex = 0, removeCount = 0, newElement = 101)
+
+        assertListCellEquals(listOf(101, 0, 1, 2, 100, 8, 9), list)
+
+        list.splice(fromIndex = list.size.value, removeCount = 0, newElement = 102)
+
+        assertListCellEquals(listOf(101, 0, 1, 2, 100, 8, 9, 102), list)
+
+        // Negative fromIndex.
+        assertFailsWith<IndexOutOfBoundsException> {
+            list.splice(fromIndex = -1, removeCount = 0, newElement = 200)
+        }
+        // fromIndex too large.
+        assertFailsWith<IndexOutOfBoundsException> {
+            list.splice(fromIndex = list.size.value + 1, removeCount = 0, newElement = 201)
+        }
+        // removeCount too large.
+        assertFailsWith<IndexOutOfBoundsException> {
+            list.splice(fromIndex = 0, removeCount = 50, newElement = 202)
+        }
+
+        // List should remain unchanged after invalid calls.
+        assertListCellEquals(listOf(101, 0, 1, 2, 100, 8, 9, 102), list)
     }
 
     @Test

observable/src/commonTest/kotlin/world/phantasmal/observable/test/Utils.kt

@@ -0,0 +1,10 @@
+package world.phantasmal.observable.test
+
+import world.phantasmal.observable.cell.list.ListCell
+import kotlin.test.assertEquals
+
+fun <E> assertListCellEquals(expected: List<E>, actual: ListCell<E>) {
+    assertEquals(expected.size, actual.size.value)
+    assertEquals(expected.size, actual.value.size)
+    assertEquals(expected, actual.value)
+}