core: remove enumerable related extensions (#7842)

src/Jackett.Common/Indexers/BaseIndexer.cs

@@ -265,7 +265,7 @@ namespace Jackett.Common.Indexers
                 return results;
 
             var filteredResults = results.Where(
-                result => result.Category.IsEmptyOrNull() || query.Categories.Intersect(result.Category).Any() ||
+                result => result.Category?.Any() != true || query.Categories.Intersect(result.Category).Any() ||
                           TorznabCatType.QueryContainsParentCategory(query.Categories, result.Category));
 
             return filteredResults;

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

@@ -85,7 +85,7 @@ namespace Jackett.Common.Indexers.Meta
                 logger.Error(aggregateTask.Exception, "Error during request in metaindexer " + ID);
             }
 
-            var unorderedResult = aggregateTask.Result.Select(r => r.Releases).Flatten();
+            var unorderedResult = aggregateTask.Result.SelectMany(r => r.Releases);
             var resultFilters = resultFilterProvider.FiltersForQuery(query);
             var filteredResults = resultFilters.Select(async f => await f.FilterResults(unorderedResult)).SelectMany(t => t.Result);
             var uniqueFilteredResults = filteredResults.Distinct();

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

@@ -24,7 +24,7 @@ namespace Jackett.Common.Indexers.Meta
 
     public class NoFallbackStrategyProvider : IFallbackStrategyProvider
     {
-        public IEnumerable<IFallbackStrategy> FallbackStrategiesForQuery(TorznabQuery query) => (new NoFallbackStrategy()).ToEnumerable();
+        public IEnumerable<IFallbackStrategy> FallbackStrategiesForQuery(TorznabQuery query) { yield return new NoFallbackStrategy(); }
     }
 
     public class ImdbFallbackStrategy : IFallbackStrategy
@@ -32,18 +32,16 @@ namespace Jackett.Common.Indexers.Meta
         public ImdbFallbackStrategy(IImdbResolver resolver, TorznabQuery query)
         {
             this.resolver = resolver;
-            titles = null;
             this.query = query;
         }
 
         public async Task<IEnumerable<TorznabQuery>> FallbackQueries()
         {
-            titles ??= (await resolver.MovieForId(query.ImdbID.ToNonNull())).Title?.ToEnumerable() ?? Enumerable.Empty<string>();
+            var title = (await resolver.MovieForId(query.ImdbID.ToNonNull())).Title;
-            return titles.Select(query.CreateFallback);
+            return title != null ? new[] {query.CreateFallback(title)} : Enumerable.Empty<TorznabQuery>();
         }
 
         private readonly IImdbResolver resolver;
-        private IEnumerable<string> titles;
         private readonly TorznabQuery query;
     }
 

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

@@ -1,3 +1,4 @@
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Threading.Tasks;
@@ -55,20 +56,16 @@ namespace Jackett.Common.Indexers.Meta
 
             var remainingResults = results.Except(wrongResults).Except(perfectResults);
 
-            var titles = (await resolver.MovieForId(query.ImdbID.ToNonNull())).Title?.ToEnumerable() ?? Enumerable.Empty<string>();
+            var title = (await resolver.MovieForId(query.ImdbID.ToNonNull())).Title;
-            var strippedTitles = titles.Select(t => RemoveSpecialChars(t));
+            if (title == null)
-            var normalizedTitles = strippedTitles.SelectMany(t => GenerateTitleVariants(t));
+                return perfectResults;
 
-            var titleFilteredResults = remainingResults.Where(r =>
+            var normalizedTitles = GenerateTitleVariants(RemoveSpecialChars(title));
-            {
-                // TODO Make it possible to configure case insensitivity
-                var containsAnyTitle = normalizedTitles.Select(t => r.Title.ToLowerInvariant().Contains(t.ToLowerInvariant()));
-                var isProbablyValidResult = containsAnyTitle.Any(b => b);
-                return isProbablyValidResult;
-            });
 
-            var filteredResults = perfectResults.Concat(titleFilteredResults).Distinct();
+            // TODO Make it possible to configure case insensitivity
-            return filteredResults;
+            var titleFilteredResults = remainingResults.Where(
+                r => normalizedTitles.Any(t => r.Title.IndexOf(t, StringComparison.InvariantCultureIgnoreCase) >= 0));
+            return perfectResults.Union(titleFilteredResults);
         }
 
         // TODO improve character replacement with invalid chars
@@ -97,7 +94,7 @@ namespace Jackett.Common.Indexers.Meta
 
     public class NoResultFilterProvider : IResultFilterProvider
     {
-        public IEnumerable<IResultFilter> FiltersForQuery(TorznabQuery query) => (new NoFilter()).ToEnumerable();
+        public IEnumerable<IResultFilter> FiltersForQuery(TorznabQuery query) { yield return new NoFilter(); }
     }
 
     public class ImdbTitleResultFilterProvider : IResultFilterProvider
@@ -106,12 +103,7 @@ namespace Jackett.Common.Indexers.Meta
 
         public IEnumerable<IResultFilter> FiltersForQuery(TorznabQuery query)
         {
-            IResultFilter filter = null;
+            yield return !query.IsImdbQuery ? (IResultFilter)new NoFilter() : new ImdbTitleResultFilter(resolver, query);
-            if (!query.IsImdbQuery)
-                filter = new NoFilter();
-            else
-                filter = new ImdbTitleResultFilter(resolver, query);
-            return filter.ToEnumerable();
         }
 
         private readonly IImdbResolver resolver;

src/Jackett.Common/Indexers/TVstore.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Globalization;
+using System.Linq;
 using System.Net;
 using System.Text;
 using System.Text.RegularExpressions;
@@ -255,12 +256,9 @@ namespace Jackett.Common.Indexers
             //TODO convert to initializer
             var releases = new List<ReleaseInfo>();
 
-            /* If series from sites are indexed than we dont need to reindex them. */
+            // If series from sites are indexed then we don't need to reindex them.
-            if (series == null || series.IsEmpty())
+            if (series?.Any() != true)
-            {
                 await GetSeriesInfo();
-            }
-
             var unixTimestamp = (int)(DateTime.UtcNow.Subtract(new DateTime(1970, 1, 1))).TotalSeconds;
 
             WebClientStringResult results;

src/Jackett.Common/Models/TorznabQuery.cs

@@ -56,7 +56,7 @@ namespace Jackett.Common.Models
                 var term = SearchTerm;
                 if (SearchTerm == null)
                     term = "";
-                var safetitle = term.Where(c => (char.IsLetterOrDigit(c)
+                var safeTitle = term.Where(c => (char.IsLetterOrDigit(c)
                                                  || char.IsWhiteSpace(c)
                                                  || c == '-'
                                                  || c == '.'
@@ -70,8 +70,8 @@ namespace Jackett.Common.Models
                                                  || c == ']'
                                                  || c == '+'
                                                  || c == '%'
-                                               )).AsString();
+                                               ));
-                return safetitle;
+                return string.Concat(safeTitle);
             }
         }
 

src/Jackett.Common/Utils/Extensions.cs

@@ -32,36 +32,18 @@ namespace Jackett.Common.Utils
 
     public static class GenericConversionExtensions
     {
-        public static IEnumerable<T> ToEnumerable<T>(this T obj) => new T[] { obj };
-
         public static NonNull<T> ToNonNull<T>(this T obj) where T : class => new NonNull<T>(obj);
     }
 
     public static class EnumerableExtension
     {
-        public static string AsString(this IEnumerable<char> chars) => string.Concat(chars);
+        public static T FirstIfSingleOrDefault<T>(this IEnumerable<T> source, T replace = default)
-
-        public static T FirstIfSingleOrDefault<T>(this IEnumerable<T> enumerable, T replace = default)
         {
-            //Avoid enumerating the whole array.
+            if (source is ICollection<T> collection)
-            //If enumerable.Count() < 2, takes whole array.
+                return collection.Count == 1 ? collection.First() : replace;
-            var test = enumerable.Take(2).ToList();
+            var test = source.Take(2).ToList();
             return test.Count == 1 ? test[0] : replace;
         }
-
-        public static IEnumerable<T> Flatten<T>(this IEnumerable<IEnumerable<T>> list) => list.SelectMany(x => x);
-    }
-
-    public static class CollectionExtension
-    {
-        // IEnumerable class above already does this. All ICollection are IEnumerable, so favor IEnumerable?
-        public static bool IsEmpty<T>(this ICollection<T> obj) => obj.Count == 0;
-
-        // obj == null || obj.IsEmpty() causes VS to suggest merging sequential checks
-        // the result is obj?.IsEmpty() == true which returns false when null
-        // Other options are obj?.IsEmpty() == true || obj == null Or (obj?.IsEmpty()).GetValueOrDefault(true)
-        // All three options remove the suggestion and give the intended result of this function
-        public static bool IsEmptyOrNull<T>(this ICollection<T> obj) => obj?.IsEmpty() ?? true;
     }
 
     public static class XElementExtension
@@ -71,11 +53,6 @@ namespace Jackett.Common.Utils
         public static string FirstValue(this XElement element, string name) => element.First(name).Value;
     }
 
-    public static class KeyValuePairsExtension
-    {
-        public static IDictionary<Key, Value> ToDictionary<Key, Value>(this IEnumerable<KeyValuePair<Key, Value>> pairs) => pairs.ToDictionary(x => x.Key, x => x.Value);
-    }
-
     public static class TaskExtensions
     {
         public static Task<IEnumerable<TResult>> Until<TResult>(this IEnumerable<Task<TResult>> tasks, TimeSpan timeout)