fix: Do not run ForceEmptySequences on string types

This happens when there's an empty `base_url:` in YAML. It comes in as a
blank string.

src/Recyclarr.Common/Extensions/TypeExtensions.cs

@@ -0,0 +1,16 @@
+namespace Recyclarr.Common.Extensions;
+
+public static class TypeExtensions
+{
+    public static bool IsGenericTypeOf(this Type type, Type genericType)
+    {
+        return type is {IsGenericType: true} && type.GetGenericTypeDefinition() == genericType;
+    }
+
+    public static bool IsImplementationOf(this Type type, Type collectionType)
+    {
+        return
+            type is {IsInterface: true} && type.IsGenericTypeOf(collectionType) ||
+            type.GetInterfaces().Any(i => i.IsGenericTypeOf(typeof(ICollection<>)));
+    }
+}

src/Recyclarr.Yaml/Recyclarr.Yaml.csproj

@@ -4,4 +4,7 @@
     <PackageReference Include="JetBrains.Annotations" />
     <PackageReference Include="YamlDotNet" />
   </ItemGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\Recyclarr.Common\Recyclarr.Common.csproj" />
+  </ItemGroup>
 </Project>

src/Recyclarr.Yaml/YamlDotNet/ForceEmptySequences.cs

@@ -1,4 +1,4 @@
-using System.Collections;
+using Recyclarr.Common.Extensions;
 using YamlDotNet.Core;
 using YamlDotNet.Core.Events;
 using YamlDotNet.Serialization;
@@ -16,7 +16,7 @@ public sealed class ForceEmptySequences(IObjectFactory objectFactory) : INodeDes
     {
         value = null;
 
-        if (!IsEnumerable(expectedType) || !reader.Accept<NodeEvent>(out var evt) || !NodeIsNull(evt))
+        if (!IsList(expectedType) || !reader.Accept<NodeEvent>(out var evt) || !NodeIsNull(evt))
         {
             return false;
         }
@@ -44,8 +44,10 @@ public sealed class ForceEmptySequences(IObjectFactory objectFactory) : INodeDes
         return value is "" or "~" or "null" or "Null" or "NULL";
     }
 
-    private static bool IsEnumerable(Type type)
+    private static bool IsList(Type type)
     {
-        return typeof(IEnumerable).IsAssignableFrom(type);
+        return
+            type.IsImplementationOf(typeof(ICollection<>)) ||
+            type.IsImplementationOf(typeof(IReadOnlyCollection<>));
     }
 }