simplify ServiceComponentList (#2566)

TechTalk.SpecFlow/Assist/Service.cs

@@ -3,16 +3,18 @@
 
 namespace TechTalk.SpecFlow.Assist
 {
+    #nullable enable
     public class Service
     {
         public ServiceComponentList<IValueComparer> ValueComparers { get; private set; }
         public ServiceComponentList<IValueRetriever> ValueRetrievers { get; private set; }
 
-        public static Service Instance { get; internal set; } = new Service();
+        public static Service Instance { get; } = new Service();
 
         public Service()
         {
-            RestoreDefaults();
+            ValueComparers = new SpecFlowDefaultValueComparerList();
+            ValueRetrievers = new SpecFlowDefaultValueRetrieverList();
         }
 
         public void RestoreDefaults()
@@ -45,12 +47,15 @@ public void UnregisterValueRetriever(IValueRetriever valueRetriever)
             ValueRetrievers.Unregister(valueRetriever);
         }
 
-        public IValueRetriever GetValueRetrieverFor(TableRow row, Type targetType, Type propertyType)
+        public IValueRetriever? GetValueRetrieverFor(TableRow row, Type targetType, Type propertyType)
         {
+            var keyValuePair = new KeyValuePair<string, string>(row[0], row[1]);
             foreach (var valueRetriever in ValueRetrievers)
             {
-                if (valueRetriever.CanRetrieve(new KeyValuePair<string, string>(row[0], row[1]), targetType, propertyType))
+                if (valueRetriever.CanRetrieve(keyValuePair, targetType, propertyType))
+                {
                     return valueRetriever;
+                }
             }
             return null;
         }

TechTalk.SpecFlow/Assist/ServiceComponentList.cs

@@ -1,26 +1,32 @@
 using System.Collections;
 using System.Collections.Generic;
-using System.Linq;
 
 namespace TechTalk.SpecFlow.Assist
 {
+    #nullable enable
     public class ServiceComponentList<T> : IEnumerable<T>
     {
         private readonly List<T> components;
+        private T? defaultComponent;
 
-        private ValueHolder<T> defaultComponent;
-
-        private IEnumerable<T> componentsWithDefault => components.Concat(defaultComponent);
-
-        IEnumerator<T> IEnumerable<T>.GetEnumerator() => componentsWithDefault.GetEnumerator();
-
-        IEnumerator IEnumerable.GetEnumerator() => ((IEnumerable)componentsWithDefault).GetEnumerator();
+        public List<T>.Enumerator GetEnumerator() => components.GetEnumerator();
+        IEnumerator<T> IEnumerable<T>.GetEnumerator() => components.GetEnumerator();
+        IEnumerator IEnumerable.GetEnumerator() => ((IEnumerable)components).GetEnumerator();
 
         public ServiceComponentList()
         {
             components = new List<T>();
         }
 
+        internal ServiceComponentList(List<T> initialList, bool isLastOneTheDefault)
+        {
+            components = initialList;
+            if (isLastOneTheDefault && initialList.Count > 0)
+            {
+                defaultComponent = initialList[initialList.Count - 1];
+            }
+        }
+
         public void Register(T component)
         {
             components.Insert(0, component);
@@ -33,18 +39,25 @@ public void Register(T component)
 
         public void Unregister(T component)
         {
-            if (!components.Remove(component))
+            if (components.Remove(component))
             {
-                if (defaultComponent.Contains(component))
+                if (ReferenceEquals(defaultComponent, component))
                 {
-                    defaultComponent = ValueHolder<T>.Empty();
+                    defaultComponent = default;
                 }
             }
         }
 
         public void Unregister<TImpl>() where TImpl : T
         {
-            componentsWithDefault.OfType<TImpl>().ToList().ForEach(component => Unregister(component));
+            for (var index = components.Count - 1; index >= 0; index--)
+            {
+                var component = components[index];
+                if (component is TImpl)
+                {
+                    Unregister(component);
+                }
+            }
         }
 
         public void Replace(T oldComponent, T newComponent)
@@ -61,7 +74,9 @@ public void Replace(T oldComponent, T newComponent)
 
         public void SetDefault(T newComponent)
         {
-            defaultComponent = ValueHolder<T>.WithValue(newComponent);
+            ClearDefault();
+            components.Add(newComponent);
+            defaultComponent = newComponent;
         }
 
         public void SetDefault<TImpl>() where TImpl : T, new()
@@ -71,13 +86,16 @@ public void SetDefault(T newComponent)
 
         public void ClearDefault()
         {
-            defaultComponent = ValueHolder<T>.Empty();
+            if (defaultComponent is not null)
+            {
+                Unregister(defaultComponent);
+            }
         }
 
         public void Clear()
         {
             components.Clear();
-            ClearDefault();
+            defaultComponent = default;
         }
     }
 }

TechTalk.SpecFlow/Assist/SpecFlowDefaultValueComparerList.cs

@@ -1,18 +1,22 @@
-using TechTalk.SpecFlow.Assist.ValueComparers;
+using System.Collections.Generic;
+using TechTalk.SpecFlow.Assist.ValueComparers;
 
 namespace TechTalk.SpecFlow.Assist
 {
-    public class SpecFlowDefaultValueComparerList : ServiceComponentList<IValueComparer>
+    #nullable enable
+    internal sealed class SpecFlowDefaultValueComparerList : ServiceComponentList<IValueComparer>
     {
         public SpecFlowDefaultValueComparerList()
+            : base(new List<IValueComparer> {
+                    new DateTimeValueComparer(),
+                    new BoolValueComparer(),
+                    new GuidValueComparer(),
+                    new DecimalValueComparer(),
+                    new DoubleValueComparer(),
+                    new FloatValueComparer(),
+                    new DefaultValueComparer(),
+                }, true)
         {
-            Register(new DateTimeValueComparer());
-            Register(new BoolValueComparer());
-            Register(new GuidValueComparer());
-            Register(new DecimalValueComparer());
-            Register(new DoubleValueComparer());
-            Register(new FloatValueComparer());
-            SetDefault(new DefaultValueComparer());
         }
     }
 }

TechTalk.SpecFlow/Assist/SpecFlowDefaultValueRetrieverList.cs

@@ -1,34 +1,38 @@
-using TechTalk.SpecFlow.Assist.ValueRetrievers;
+using System.Collections.Generic;
+using TechTalk.SpecFlow.Assist.ValueRetrievers;
 
 namespace TechTalk.SpecFlow.Assist
 {
-    internal class SpecFlowDefaultValueRetrieverList : ServiceComponentList<IValueRetriever>
+    #nullable enable
+    internal sealed class SpecFlowDefaultValueRetrieverList : ServiceComponentList<IValueRetriever>
     {
         public SpecFlowDefaultValueRetrieverList()
+            : base(new List<IValueRetriever> {
+                // Sorted by likelihood
+                new StringValueRetriever(),
+                new IntValueRetriever(),
+                new BoolValueRetriever(),
+                new LongValueRetriever(),
+                new FloatValueRetriever(),
+                new DoubleValueRetriever(),
+                new DateTimeValueRetriever(),
+                new TimeSpanValueRetriever(),
+                new GuidValueRetriever(),
+                new EnumValueRetriever(),
+                new ListValueRetriever(),
+                new ArrayValueRetriever(),
+                new ByteValueRetriever(),
+                new SByteValueRetriever(),
+                new UIntValueRetriever(),
+                new ShortValueRetriever(),
+                new UShortValueRetriever(),
+                new ULongValueRetriever(),
+                new DecimalValueRetriever(),
+                new CharValueRetriever(),
+                new DateTimeOffsetValueRetriever(),
+                new UriValueRetriever()
+            }, false)
         {
-            Register(new StringValueRetriever());
-            Register(new ByteValueRetriever());
-            Register(new SByteValueRetriever());
-            Register(new IntValueRetriever());
-            Register(new UIntValueRetriever());
-            Register(new ShortValueRetriever());
-            Register(new UShortValueRetriever());
-            Register(new LongValueRetriever());
-            Register(new ULongValueRetriever());
-            Register(new FloatValueRetriever());
-            Register(new DoubleValueRetriever());
-            Register(new DecimalValueRetriever());
-            Register(new CharValueRetriever());
-            Register(new BoolValueRetriever());
-            Register(new DateTimeValueRetriever());
-            Register(new GuidValueRetriever());
-            Register(new EnumValueRetriever());
-            Register(new TimeSpanValueRetriever());
-            Register(new DateTimeOffsetValueRetriever());
-            Register(new UriValueRetriever());
-
-            Register(new ArrayValueRetriever());
-            Register(new ListValueRetriever());
         }
     }
 }

TechTalk.SpecFlow/Assist/ValueRetrievers/EnumerableValueRetriever.cs

@@ -40,7 +40,7 @@ private IEnumerable GetItems(string[] strings, KeyValuePair<string, string> keyV
             foreach (var splitValue in strings)
             {
                 var itemKeyValuePair = new KeyValuePair<string, string>(keyValuePair.Key, splitValue.Trim());
-                retriever = retriever ?? GetValueRetriever(itemKeyValuePair, targetType, itemType);
+                retriever ??= GetValueRetriever(itemKeyValuePair, targetType, itemType);
                 yield return retriever?.Retrieve(itemKeyValuePair, targetType, itemType);
             }
         }
@@ -49,7 +49,7 @@ private IEnumerable GetItems(string[] strings, KeyValuePair<string, string> keyV
 
         protected abstract object BuildInstance(int count, IEnumerable values, Type valueType);
 
-        private IValueRetriever GetValueRetriever(KeyValuePair<string, string> keyValuePair, Type targetType, Type valueType)
+        private static IValueRetriever GetValueRetriever(KeyValuePair<string, string> keyValuePair, Type targetType, Type valueType)
         {
             foreach (var retriever in Service.Instance.ValueRetrievers)
             {

changelog.txt

@@ -1,3 +1,8 @@
+3.9.52
+
+Changes:
++ improve Service.GetValueRetrieverFor performance
+
 3.9.40
 
 Changes: