Pass non mapping to base serializer

Tests/powershell-yaml.Tests.ps1

@@ -1,4 +1,4 @@
-# Copyright 2016-2024 Cloudbase Solutions Srl
+# Copyright 2016-2024 Cloudbase Solutions Srl
 #
 #    Licensed under the Apache License, Version 2.0 (the "License"); you may
 #    not use this file except in compliance with the License. You may obtain
@@ -190,6 +190,22 @@ children:
     }
 
     Describe "Test PSCustomObject wrapped values are serialized correctly" {
+        Context "A PSCustomObject that contains an array of PSObjects" {
+            It "Should serialize correctly" {
+                $expected = @"
+yamlList:
+- item1
+- item2
+
+"@
+                $data = ConvertFrom-YAml "yamlList: []" | ConvertTo-JSON -Depth 3 | ConvertFrom-Json
+                $jsData = '["item1", "item2"]'
+                $data.yamlList = $jsData | ConvertFrom-Json
+
+                $asYaml = ConvertTo-Yaml $data
+                Assert-Equivalent -Options $compareStrictly -Expected $expected -Actual $asYaml
+            }
+        }
         Context "A PSCustomObject containing nested PSCustomObjects" {
             It "Should serialize correctly" {
                 $expectBigInt = [System.Numerics.BigInteger]::Parse("9999999999999999999999999999999999999999999999999")

src/PowerShellYamlSerializer.cs

@@ -124,6 +124,10 @@ public object ReadYaml(IParser parser, Type type, ObjectDeserializer rootDeseria
 
     public void WriteYaml(IEmitter emitter, object value, Type type, ObjectSerializer serializer) {
         var psObj = (PSObject)value;
+        if (!typeof(IDictionary).IsAssignableFrom(psObj.BaseObject.GetType()) && !typeof(PSCustomObject).IsAssignableFrom(psObj.BaseObject.GetType())) {
+            serializer(psObj.BaseObject, psObj.BaseObject.GetType());
+            return;
+        }
         var mappingStyle = this.useFlowStyle ? MappingStyle.Flow : MappingStyle.Block;
         emitter.Emit(new MappingStart(AnchorName.Empty, TagName.Empty, true, mappingStyle));
         foreach (var prop in psObj.Properties) {