Fix issue that TryGetValue might return null

Author: Erwinvandervalk

src/TemplatedConfiguration/TemplatedConfiguration.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <TargetFramework>netstandard2.0</TargetFramework>
-    <Version>1.0.0</Version>
+    <Version>1.0.1</Version>
     <PackageProjectUrl>https://github.com/erwinvandervalk/templatedconfiguration/</PackageProjectUrl>
     <PackageTags></PackageTags>
     <RepositoryUrl>https://github.com/erwinvandervalk/templatedconfiguration/</RepositoryUrl>

src/TemplatedConfiguration/TemplatedConfigurationProvider.cs

@@ -45,6 +45,11 @@ public TemplatedConfigurationProvider(IConfigurationRoot innerConfiguration)
 
         public override bool TryGet(string key, out string value)
         {
+            if (string.IsNullOrEmpty(key))
+            {
+                value = null;
+                return false;
+            }
             return TryGetInternal(key, new HashSet<TemplatedSettingKey>(), out value);
         }