Netcore: migrate more unittests (#8939)

* Migrated unit tests

* Migrated CoreThings tests

Signed-off-by: Bjarke Berg <mail@bergmania.dk>

* Migrated Property Editor unit tests

Signed-off-by: Bjarke Berg <mail@bergmania.dk>

* Migrated CoreXml tests

Signed-off-by: Bjarke Berg <mail@bergmania.dk>

* Moved more tests

Signed-off-by: Bjarke Berg <mail@bergmania.dk>

* revert some IsSZArray test code

Signed-off-by: Bjarke Berg <mail@bergmania.dk>

* Renamed bad named test

Signed-off-by: Bjarke Berg <mail@bergmania.dk>

* removed unnecessary file mentions in csproj file

Signed-off-by: Bjarke Berg <mail@bergmania.dk>

Co-authored-by: Elitsa Marinovska <elm@umbraco.dk>

src/Umbraco.Infrastructure/Compose/NestedContentPropertyComponent.cs

@@ -0,0 +1,85 @@
+using System;
+using System.Linq;
+using Newtonsoft.Json.Linq;
+using Umbraco.Core;
+using Umbraco.Core.Composing;
+using Umbraco.Core.PropertyEditors;
+using Umbraco.Web.PropertyEditors;
+
+namespace Umbraco.Web.Compose
+{
+
+    /// <summary>
+    /// A component for NestedContent used to bind to events
+    /// </summary>
+    public class NestedContentPropertyComponent : IComponent
+    {
+        private ComplexPropertyEditorContentEventHandler _handler;
+
+        public void Initialize()
+        {
+            _handler = new ComplexPropertyEditorContentEventHandler(
+                Constants.PropertyEditors.Aliases.NestedContent,
+                CreateNestedContentKeys);
+        }
+
+        public void Terminate() => _handler?.Dispose();
+
+        private string CreateNestedContentKeys(string rawJson, bool onlyMissingKeys) => CreateNestedContentKeys(rawJson, onlyMissingKeys, null);
+
+        // internal for tests
+        internal string CreateNestedContentKeys(string rawJson, bool onlyMissingKeys, Func<Guid> createGuid = null)
+        {
+            // used so we can test nicely
+            if (createGuid == null)
+                createGuid = () => Guid.NewGuid();
+
+            if (string.IsNullOrWhiteSpace(rawJson) || !rawJson.DetectIsJson())
+                return rawJson;
+
+            // Parse JSON
+            var complexEditorValue = JToken.Parse(rawJson);
+
+            UpdateNestedContentKeysRecursively(complexEditorValue, onlyMissingKeys, createGuid);
+
+            return complexEditorValue.ToString();
+        }
+
+        private void UpdateNestedContentKeysRecursively(JToken json, bool onlyMissingKeys, Func<Guid> createGuid)
+        {
+            // check if this is NC
+            var isNestedContent = json.SelectTokens($"$..['{NestedContentPropertyEditor.ContentTypeAliasPropertyKey}']", false).Any();
+
+            // select all values (flatten)
+            var allProperties = json.SelectTokens("$..*").OfType<JValue>().Select(x => x.Parent as JProperty).WhereNotNull().ToList();
+            foreach (var prop in allProperties)
+            {
+                if (prop.Name == NestedContentPropertyEditor.ContentTypeAliasPropertyKey)
+                {
+                    // get it's sibling 'key' property
+                    var ncKeyVal = prop.Parent["key"] as JValue;
+                    if ((onlyMissingKeys && ncKeyVal == null) || (!onlyMissingKeys && ncKeyVal != null))
+                    {
+                        // create or replace
+                        prop.Parent["key"] = createGuid().ToString();
+                    }
+                }
+                else if (!isNestedContent || prop.Name != "key")
+                {
+                    // this is an arbitrary property that could contain a nested complex editor
+                    var propVal = prop.Value?.ToString();
+                    // check if this might contain a nested NC
+                    if (!propVal.IsNullOrWhiteSpace() && propVal.DetectIsJson() && propVal.InvariantContains(NestedContentPropertyEditor.ContentTypeAliasPropertyKey))
+                    {
+                        // recurse
+                        var parsed = JToken.Parse(propVal);
+                        UpdateNestedContentKeysRecursively(parsed, onlyMissingKeys, createGuid);
+                        // set the value to the updated one
+                        prop.Value = parsed.ToString();
+                    }
+                }
+            }
+        }
+
+    }
+}