Refactoring: Remove redundant logic from "Not" converters (#935)

* Convert "Not" converters to use existing logic

* Revert "Convert "Not" converters to use existing logic"

This reverts commit 62c43e1.

* Use ststic method instead of inheritance

* Commit to rerun tests

Co-authored-by: Pedro Jesus <pedrojesus.cefet@gmail.com>
Co-authored-by: Javier Suárez <javiersuarezruiz@hotmail.com>

src/CommunityToolkit/Xamarin.CommunityToolkit/Converters/EqualConverter.shared.cs

@@ -18,8 +18,10 @@ public class EqualConverter : ValueConverterExtension, IValueConverter
 		/// <param name="parameter">The second object to compare.</param>
 		/// <param name="culture">The culture to use in the converter. This is not implemented.</param>
 		/// <returns>True if <paramref name="value"/> and <paramref name="parameter"/> are equal, False if they are not equal.</returns>
-		public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
-			=> (value != null && value.Equals(parameter)) || (value == null && parameter == null);
+		public object Convert(object value, Type targetType, object parameter, CultureInfo culture) => ConvertInternal(value, parameter);
+
+		internal static bool ConvertInternal(object value, object parameter) =>
+			(value != null && value.Equals(parameter)) || (value == null && parameter == null);
 
 		/// <summary>
 		/// This method is not implemented and will throw a <see cref="NotImplementedException"/>.
@@ -29,7 +31,7 @@ public object Convert(object value, Type targetType, object parameter, CultureIn
 		/// <param name="parameter">N/A</param>
 		/// <param name="culture">N/A</param>
 		/// <returns>N/A</returns>
-		public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
-			=> throw new NotImplementedException();
+		public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture) =>
+			throw new NotImplementedException();
 	}
 }

src/CommunityToolkit/Xamarin.CommunityToolkit/Converters/IsNotNullOrEmptyConverter.shared.cs

@@ -18,8 +18,8 @@ public class IsNotNullOrEmptyConverter : ValueConverterExtension, IValueConverte
 		/// <param name="parameter">Additional parameter for the converter to handle. This is not implemented.</param>
 		/// <param name="culture">The culture to use in the converter. This is not implemented.</param>
 		/// <returns>A <see cref="bool"/> indicating if the incoming value is not null and not empty.</returns>
-		public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
-			=> value is string str ? !string.IsNullOrWhiteSpace(str) : value != null;
+		public object Convert(object value, Type targetType, object parameter, CultureInfo culture) =>
+			!IsNullOrEmptyConverter.ConvertInternal(value);
 
 		/// <summary>
 		/// This method is not implemented and will throw a <see cref="NotImplementedException"/>.

src/CommunityToolkit/Xamarin.CommunityToolkit/Converters/IsNullOrEmptyConverter.shared.cs

@@ -18,8 +18,10 @@ public class IsNullOrEmptyConverter : ValueConverterExtension, IValueConverter
 		/// <param name="parameter">Additional parameter for the converter to handle. This is not implemented.</param>
 		/// <param name="culture">The culture to use in the converter. This is not implemented.</param>
 		/// <returns>A <see cref="bool"/> indicating if the incoming value is null or empty.</returns>
-		public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
-			=> value == null || (value is string str && string.IsNullOrWhiteSpace(str));
+		public object Convert(object value, Type targetType, object parameter, CultureInfo culture) => ConvertInternal(value);
+
+		internal static bool ConvertInternal(object value) =>
+			value == null || (value is string str && string.IsNullOrWhiteSpace(str));
 
 		/// <summary>
 		/// This method is not implemented and will throw a <see cref="NotImplementedException"/>.

src/CommunityToolkit/Xamarin.CommunityToolkit/Converters/ListIsNotNullOrEmptyConverter.shared.cs

@@ -1,5 +1,4 @@
 using System;
-using System.Collections;
 using System.Globalization;
 using Xamarin.CommunityToolkit.Extensions.Internals;
 using Xamarin.Forms;
@@ -19,16 +18,8 @@ public class ListIsNotNullOrEmptyConverter : ValueConverterExtension, IValueConv
 		/// <param name="parameter">Additional parameter for the converter to handle. This is not implemented.</param>
 		/// <param name="culture">The culture to use in the converter. This is not implemented.</param>
 		/// <returns>A <see cref="bool"/> indicating if the incoming value is not null and not empty.</returns>
-		public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
-		{
-			if (value is null)
-				return false;
-
-			if (value is IEnumerable list)
-				return list.GetEnumerator().MoveNext();
-
-			throw new ArgumentException("Value is not a valid IEnumerable or null", nameof(value));
-		}
+		public object Convert(object value, Type targetType, object parameter, CultureInfo culture) =>
+			!ListIsNullOrEmptyConverter.ConvertInternal(value);
 
 		/// <summary>
 		/// This method is not implemented and will throw a <see cref="NotImplementedException"/>.

src/CommunityToolkit/Xamarin.CommunityToolkit/Converters/ListIsNullOrEmptyConverter.shared.cs

@@ -19,7 +19,9 @@ public class ListIsNullOrEmptyConverter : ValueConverterExtension, IValueConvert
 		/// <param name="parameter">Additional parameter for the converter to handle. This is not implemented.</param>
 		/// <param name="culture">The culture to use in the converter. This is not implemented.</param>
 		/// <returns>A <see cref="bool"/> indicating if the incoming value is null or empty.</returns>
-		public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
+		public object Convert(object value, Type targetType, object parameter, CultureInfo culture) => ConvertInternal(value);
+
+		internal static bool ConvertInternal(object value)
 		{
 			if (value is null)
 				return true;

src/CommunityToolkit/Xamarin.CommunityToolkit/Converters/NotEqualConverter.shared.cs

@@ -18,8 +18,8 @@ public class NotEqualConverter : ValueConverterExtension, IValueConverter
 		/// <param name="parameter">The second object to compare.</param>
 		/// <param name="culture">The culture to use in the converter. This is not implemented.</param>
 		/// <returns>True if <paramref name="value"/> and <paramref name="parameter"/> are not equal, False if they are equal.</returns>
-		public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
-			=> !((value != null && value.Equals(parameter)) || (value == null && parameter == null));
+		public object Convert(object value, Type targetType, object parameter, CultureInfo culture) =>
+			!EqualConverter.ConvertInternal(value, parameter);
 
 		/// <summary>
 		/// This method is not implemented and will throw a <see cref="NotImplementedException"/>.