add test case for custom nullable descriptor

Kotlin · Apr 18, 2024 · 588a5ae · 588a5ae
1 parent 4ba619d
commit 588a5ae
Showing 1 changed file with 24 additions and 4 deletions.
diff --git a/core/commonTest/src/kotlinx/serialization/SerialDescriptorBuilderTest.kt b/core/commonTest/src/kotlinx/serialization/SerialDescriptorBuilderTest.kt
@@ -103,15 +103,35 @@ class SerialDescriptorBuilderTest {
             String.serializer().descriptor,
             ListSerializer(Int.serializer()).descriptor,
         ).forEach { originalDescriptor ->
-            // Unwrapping nullable when it is not nullable should return the same descriptor (no-op operation)
+            // Unwrapping original descriptor when it is not nullable should return the same descriptor (no-op operation)
             assertSame(originalDescriptor.nonNullOriginal, originalDescriptor)
 
-            // Unwrapping nullable when it is nullable should return the original descriptor
+            // Unwrapping original descriptor when it is nullable should return the original descriptor
             assertSame(originalDescriptor.nullable.nonNullOriginal, originalDescriptor)
         }
 
-        @Serializable class Type(val field: String?)
-        // Unwrapping nullable of a nullable field should return the original non-null descriptor
+        // Unwrapping original descriptor of a custom nullable descriptor should return the same descriptor
+        val customNullableDescriptor = CustomNullableDescriptor()
+        assertSame(customNullableDescriptor.nonNullOriginal, customNullableDescriptor)
+
+        // Unwrapping original descriptor of a nullable field should return the original non-null descriptor
         assertSame(Type.serializer().descriptor.getElementDescriptor(0).nonNullOriginal, String.serializer().descriptor)
+
+    }
+
+    @Serializable
+    class Type(val field: String?)
+
+    private class CustomNullableDescriptor : SerialDescriptor {
+        override val isNullable: Boolean = true
+
+        override val serialName: String = "CustomNullableDescriptor"
+        override val kind: SerialKind = PrimitiveKind.STRING
+        override val elementsCount: Int = 0
+        override fun getElementName(index: Int): String = error("Should not be called")
+        override fun getElementIndex(name: String): Int = error("Should not be called")
+        override fun isElementOptional(index: Int): Boolean = error("Should not be called")
+        override fun getElementAnnotations(index: Int): List<Annotation> = error("Should not be called")
+        override fun getElementDescriptor(index: Int): SerialDescriptor = error("Should not be called")
     }
 }