core: Remove non-null extention classes. (#7979)

src/Jackett.Common/Indexers/Meta/Fallbacks.cs

@@ -37,9 +37,11 @@ namespace Jackett.Common.Indexers.Meta
 
         public async Task<IEnumerable<TorznabQuery>> FallbackQueries()
         {
-            var title = (await resolver.MovieForId(query.ImdbID.ToNonNull())).Title;
+	        if(string.IsNullOrEmpty(query.ImdbID))
+				return Enumerable.Empty<TorznabQuery>();
+	        var title = (await resolver.MovieForId(query.ImdbID)).Title;
             return title != null ? new[] {query.CreateFallback(title)} : Enumerable.Empty<TorznabQuery>();
-        }
+	    }
 
         private readonly IImdbResolver resolver;
         private readonly TorznabQuery query;

src/Jackett.Common/Indexers/Meta/ResultFilters.cs

@@ -56,7 +56,9 @@ namespace Jackett.Common.Indexers.Meta
 
             var remainingResults = results.Except(wrongResults).Except(perfectResults);
 
-            var title = (await resolver.MovieForId(query.ImdbID.ToNonNull())).Title;
+            if (string.IsNullOrEmpty(query.ImdbID))
+                return perfectResults;
+            var title = (await resolver.MovieForId(query.ImdbID)).Title;
             if (title == null)
                 return perfectResults;
 

src/Jackett.Common/Services/ImdbResolver.cs

@@ -17,16 +17,16 @@ namespace Jackett.Common.Services
 
     public class OmdbResolver : IImdbResolver
     {
-        public OmdbResolver(WebClient webClient, NonNull<string> omdbApiKey, string omdbApiUrl)
+        public OmdbResolver(WebClient webClient, string omdbApiKey, string omdbApiUrl)
         {
             WebClient = webClient;
-            apiKey = omdbApiKey;
+            apiKey = omdbApiKey ?? throw new ArgumentNullException($"{nameof(omdbApiKey)} cannot be null");
             url = omdbApiUrl;
         }
 
-        public async Task<Movie> MovieForId(NonNull<string> id)
+        public async Task<Movie> MovieForId(string id)
         {
-            string imdbId = id;
+            var imdbId = id ?? throw new ArgumentNullException($"{nameof(id)} cannot be null");
 
             if (!imdbId.StartsWith("tt", StringComparison.Ordinal))
                 imdbId = "tt" + imdbId;

src/Jackett.Common/Services/IndexerManagerService.cs

@@ -161,7 +161,7 @@ namespace Jackett.Common.Services
             IResultFilterProvider resultFilterProvider = null;
             if (!string.IsNullOrWhiteSpace(omdbApiKey))
             {
-                var imdbResolver = new OmdbResolver(webClient, omdbApiKey.ToNonNull(), serverConfig.OmdbApiUrl);
+                var imdbResolver = new OmdbResolver(webClient, omdbApiKey, serverConfig.OmdbApiUrl);
                 fallbackStrategyProvider = new ImdbFallbackStrategyProvider(imdbResolver);
                 resultFilterProvider = new ImdbTitleResultFilterProvider(imdbResolver);
             }

src/Jackett.Common/Services/Interfaces/IImdbResolver.cs

@@ -5,6 +5,6 @@ namespace Jackett.Common.Services.Interfaces
 {
     public interface IImdbResolver
     {
-        Task<Movie> MovieForId(NonNull<string> imdbId);
+        Task<Movie> MovieForId(string imdbId);
     }
 }

src/Jackett.Common/Utils/Extensions.cs

@@ -6,35 +6,6 @@ using System.Xml.Linq;
 
 namespace Jackett.Common.Utils
 {
-    // Prefer built in NullReferenceException || ArgumentNullException || NoNullAllowedException
-    public class NonNullException : Exception
-    {
-        public NonNullException() : base("Parameter cannot be null")
-        {
-        }
-    }
-
-    public class NonNull<T> where T : class
-    {
-        public NonNull(T val)
-        {
-            // doesn't throw Exception?
-            if (val == null)
-                new NonNullException();
-
-            Value = val;
-        }
-
-        public static implicit operator T(NonNull<T> n) => n.Value;
-
-        private readonly T Value;
-    }
-
-    public static class GenericConversionExtensions
-    {
-        public static NonNull<T> ToNonNull<T>(this T obj) where T : class => new NonNull<T>(obj);
-    }
-
     public static class EnumerableExtension
     {
         public static T FirstIfSingleOrDefault<T>(this IEnumerable<T> source, T replace = default)