refactor: reduce allocations for context

Benchmarks/aweXpect.Benchmarks/HappyCaseBenchmarks.String.cs

@@ -10,17 +10,17 @@ namespace aweXpect.Benchmarks;
 public partial class HappyCaseBenchmarks
 {
 	private readonly string _stringExpectation = "foo";
-	private readonly string _stringSubject = "foo";
+	private readonly string _stringSubject = "FOO";
 
 	[Benchmark]
 	public async Task<string?> String_aweXpect()
-		=> await Expect.That(_stringSubject).IsEqualTo(_stringExpectation);
+		=> await Expect.That(_stringSubject).IsEqualTo(_stringExpectation).IgnoringCase();
 
 	[Benchmark]
 	public AndConstraint<StringAssertions> String_FluentAssertions()
-		=> _stringSubject.Should().Be(_stringExpectation);
+		=> _stringSubject.Should().BeEquivalentTo(_stringExpectation, o => o.IgnoringCase());
 
 	[Benchmark]
 	public async Task<string?> String_TUnit()
-		=> await Assert.That(_stringSubject).IsEqualTo(_stringExpectation);
+		=> await Assert.That(_stringSubject).IsEqualTo(_stringExpectation).IgnoringCase();
 }

Pipeline/Build.cs

@@ -20,7 +20,7 @@ partial class Build : NukeBuild
 	///     <para />
 	///     Afterward, you can update the package reference in `Directory.Packages.props` and reset this flag.
 	/// </summary>
-	readonly BuildScope BuildScope = BuildScope.Default;
+	readonly BuildScope BuildScope = BuildScope.CoreOnly;
 
 	[Parameter("Github Token")] readonly string GithubToken;
 	[GitRepository] readonly GitRepository Repository;

Source/aweXpect.Core/Core/Constraints/ConstraintResult.FromException.cs

@@ -30,7 +30,7 @@ public FromException(
 			_inner = inner;
 			_exception = exception;
 			FurtherProcessingStrategy = inner.FurtherProcessingStrategy;
-			expectationBuilder.UpdateContexts(c => c.Add(new ResultContext("Exception", exception.ToString())));
+			expectationBuilder.AddContext(new ResultContext.Fixed("Exception", exception.ToString()));
 		}
 
 		public override Outcome Outcome

Source/aweXpect.Core/Core/ExpectationBuilder.cs

@@ -378,6 +378,16 @@ public virtual ExpectationBuilder UpdateContexts(Action<ResultContexts> callback
 		return this;
 	}
 
+	/// <summary>
+	///     Adds the <paramref name="resultContext"/> to the context that is included in the failure message.
+	/// </summary>
+	public virtual ExpectationBuilder AddContext(ResultContext resultContext)
+	{
+		_contexts ??= new ResultContexts();
+		_contexts.Add(resultContext);
+		return this;
+	}
+
 	/// <summary>
 	///     Gets the list of <see cref="ResultContext" />.
 	/// </summary>

Source/aweXpect.Core/Core/IStringMatchType.cs

@@ -1,4 +1,5 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 using System.Threading.Tasks;
 
 namespace aweXpect.Core;
@@ -19,7 +20,7 @@ public interface IStringMatchType
 #endif
 	AreConsideredEqual(string? actual, string? expected,
 		bool ignoreCase,
-		IEqualityComparer<string> comparer);
+		IEqualityComparer<string>? comparer);
 
 	/// <summary>
 	///     Get the expectations text.

Source/aweXpect.Core/Core/ManualExpectationBuilder.cs

@@ -83,6 +83,14 @@ public override ExpectationBuilder UpdateContexts(Action<ResultContexts> callbac
 		return this;
 	}
 
+	/// <inheritdoc cref="ExpectationBuilder.AddContext(ResultContext)" />
+	public override ExpectationBuilder AddContext(ResultContext resultContext)
+	{
+		inner?.AddContext(resultContext);
+		base.AddContext(resultContext);
+		return this;
+	}
+
 	/// <inheritdoc cref="object.ToString()" />
 	public override string ToString()
 	{

Source/aweXpect.Core/Core/Polyfills/StringExtensions.cs

@@ -23,7 +23,7 @@ internal static bool Contains(
 		this string @this,
 		char value,
 		StringComparison comparisonType)
-		=> @this.Contains(value);
+		=> @this.IndexOf(value, comparisonType) >= 0;
 
 	/// <summary>
 	///     Returns a value indicating whether a specified character occurs within this string, using the specified comparison
@@ -37,7 +37,7 @@ internal static bool Contains(
 		this string @this,
 		string value,
 		StringComparison comparisonType)
-		=> @this.Contains(value);
+		=> @this.IndexOf(value, comparisonType) >= 0;
 
 	/// <summary>
 	///     Determines whether the end of this string instance matches the specified character.

Source/aweXpect.Core/Core/ResultContext.cs

@@ -7,42 +7,17 @@ namespace aweXpect.Core;
 /// <summary>
 ///     A result context that is appended to a result error.
 /// </summary>
-public class ResultContext
+public abstract class ResultContext
 {
-	private readonly Func<CancellationToken, Task<string?>>? _contentFunc;
-
-	private readonly string? _fixedContent;
-
-	/// <summary>
-	///     A result context that is appended to a result error.
-	/// </summary>
-	/// <remarks>The optional <paramref name="priority" /> determines the displayed order (higher values are displayed first).</remarks>
-	public ResultContext(string title, string? content, int priority = 0)
-	{
-		Title = title;
-		_fixedContent = content;
-		Priority = priority;
-	}
-
-	/// <summary>
-	///     A result context that is appended to a result error.
-	/// </summary>
-	/// <remarks>The optional <paramref name="priority" /> determines the displayed order (higher values are displayed first).</remarks>
-	public ResultContext(string title, Func<CancellationToken, Task<string?>> asyncContent, int priority = 0)
-	{
-		Title = title;
-		_contentFunc = asyncContent;
-		Priority = priority;
-	}
+	internal ResultContext? _next;
 
 	/// <summary>
 	///     A result context that is appended to a result error.
 	/// </summary>
 	/// <remarks>The optional <paramref name="priority" /> determines the displayed order (higher values are displayed first).</remarks>
-	public ResultContext(string title, Func<string?> syncContent, int priority = 0)
+	protected ResultContext(string title, int priority = 0)
 	{
 		Title = title;
-		_contentFunc = _ => Task.FromResult(syncContent());
 		Priority = priority;
 	}
 
@@ -60,18 +35,69 @@ public ResultContext(string title, Func<string?> syncContent, int priority = 0)
 	/// <summary>
 	///     The content of the context.
 	/// </summary>
-	public async Task<string?> GetContent(CancellationToken cancellationToken = default)
+	public abstract Task<string?> GetContent(CancellationToken cancellationToken = default);
+
+	/// <summary>
+	///     A <see cref="ResultContext" /> from a fixed <see langword="string" /> content.
+	/// </summary>
+	public class Fixed : ResultContext
 	{
-		if (_fixedContent is not null)
+		private readonly string? _content;
+
+		/// <summary>
+		///     A <see cref="ResultContext" /> from a fixed <see langword="string" /> <paramref name="content" />.
+		/// </summary>
+		/// <remarks>The optional <paramref name="priority" /> determines the displayed order (higher values are displayed first).</remarks>
+		public Fixed(string title, string? content, int priority = 0) : base(title, priority)
 		{
-			return _fixedContent;
+			_content = content;
 		}
 
-		if (_contentFunc is not null)
+		/// <inheritdoc cref="ResultContext.GetContent(CancellationToken)" />
+		public override Task<string?> GetContent(CancellationToken cancellationToken = default)
+			=> Task.FromResult(_content);
+	}
+
+	/// <summary>
+	///     A <see cref="ResultContext" /> from an async callback.
+	/// </summary>
+	public class AsyncCallback : ResultContext
+	{
+		private readonly Func<CancellationToken, Task<string?>> _callback;
+
+		/// <summary>
+		///     A <see cref="ResultContext" /> from an async <paramref name="callback" />.
+		/// </summary>
+		/// <remarks>The optional <paramref name="priority" /> determines the displayed order (higher values are displayed first).</remarks>
+		public AsyncCallback(string title, Func<CancellationToken, Task<string?>> callback, int priority = 0) : base(
+			title, priority)
+		{
+			_callback = callback;
+		}
+
+		/// <inheritdoc cref="ResultContext.GetContent(CancellationToken)" />
+		public override Task<string?> GetContent(CancellationToken cancellationToken = default)
+			=> _callback(cancellationToken);
+	}
+
+	/// <summary>
+	///     A <see cref="ResultContext" /> from a sync callback.
+	/// </summary>
+	public class SyncCallback : ResultContext
+	{
+		private readonly Func<string?> _callback;
+
+		/// <summary>
+		///     A <see cref="ResultContext" /> from a sync <paramref name="callback" />.
+		/// </summary>
+		/// <remarks>The optional <paramref name="priority" /> determines the displayed order (higher values are displayed first).</remarks>
+		public SyncCallback(string title, Func<string?> callback, int priority = 0) : base(title, priority)
 		{
-			return await _contentFunc(cancellationToken);
+			_callback = callback;
 		}
 
-		return null;
+		/// <inheritdoc cref="ResultContext.GetContent(CancellationToken)" />
+		public override Task<string?> GetContent(CancellationToken cancellationToken = default)
+			=> Task.FromResult(_callback());
 	}
 }

Source/aweXpect.Core/Core/ResultContexts.cs

@@ -9,11 +9,19 @@ namespace aweXpect.Core;
 /// </summary>
 public class ResultContexts : IEnumerable<ResultContext>
 {
-	private readonly List<ResultContext> _results = new();
+	private ResultContext? _first;
 	private bool _isOpen = true;
 
 	/// <inheritdoc cref="IEnumerable{ResultContext}.GetEnumerator()" />
-	public IEnumerator<ResultContext> GetEnumerator() => _results.GetEnumerator();
+	public IEnumerator<ResultContext> GetEnumerator()
+	{
+		ResultContext? current = _first;
+		while (current != null)
+		{
+			yield return current;
+			current = current._next;
+		}
+	}
 
 	/// <inheritdoc cref="IEnumerable.GetEnumerator()" />
 	IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();
@@ -43,7 +51,15 @@ public ResultContexts Add(ResultContext context)
 	{
 		if (_isOpen)
 		{
-			_results.Add(context);
+			if (_first is null)
+			{
+				_first = context;
+			}
+			else
+			{
+				context._next = _first._next;
+				_first._next = context;
+			}
 		}
 
 		return this;
@@ -56,7 +72,7 @@ public ResultContexts Clear()
 	{
 		if (_isOpen)
 		{
-			_results.Clear();
+			_first = null;
 		}
 
 		return this;
@@ -66,14 +82,7 @@ public ResultContexts Clear()
 	///     Removes all contexts with the given <paramref name="title" />.
 	/// </summary>
 	public ResultContexts Remove(string title, StringComparison stringComparison = StringComparison.OrdinalIgnoreCase)
-	{
-		if (_isOpen)
-		{
-			_results.RemoveAll(x => x.Title.Equals(title, stringComparison));
-		}
-
-		return this;
-	}
+		=> Remove(c => string.Equals(c.Title, title, stringComparison));
 
 	/// <summary>
 	///     Removes all contexts that match the <paramref name="predicate" />.
@@ -82,7 +91,28 @@ public ResultContexts Remove(Predicate<ResultContext> predicate)
 	{
 		if (_isOpen)
 		{
-			_results.RemoveAll(predicate);
+			ResultContext? previous = null;
+			ResultContext? current = _first;
+			while (current != null)
+			{
+				if (predicate(current))
+				{
+					if (previous == null)
+					{
+						_first = current._next;
+					}
+					else
+					{
+						previous._next = current._next;
+					}
+				}
+				else
+				{
+					previous = current;
+				}
+
+				current = current._next;
+			}
 		}
 
 		return this;

Source/aweXpect.Core/Core/ThatBool.cs

@@ -36,6 +36,9 @@ private sealed class WithDefaultExpectationBuilderProxy(ExpectationBuilder inner
 		public override ExpectationBuilder UpdateContexts(Action<ResultContexts> callback)
 			=> inner.UpdateContexts(callback);
 
+		public override ExpectationBuilder AddContext(ResultContext resultContext)
+			=> inner.AddContext(resultContext);
+
 		internal override Task<ConstraintResult> IsMet(Node rootNode, EvaluationContext.EvaluationContext context,
 			ITimeSystem timeSystem, TimeSpan? timeout,
 			CancellationToken cancellationToken)

Source/aweXpect.Core/Equivalency/EquivalencyExpectationBuilder.cs

@@ -134,4 +134,7 @@ internal override Task<ConstraintResult> IsMet(Node rootNode,
 
 	/// <inheritdoc cref="ExpectationBuilder.UpdateContexts(Action{ResultContexts})" />
 	public override ExpectationBuilder UpdateContexts(Action<ResultContexts> callback) => this;
+
+	/// <inheritdoc cref="ExpectationBuilder.AddContext(ResultContext)" />
+	public override ExpectationBuilder AddContext(ResultContext resultContext) => this;
 }

Source/aweXpect.Core/Options/StringEqualityOptions.ContainingMatchType.cs

@@ -1,4 +1,5 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 using System.Threading.Tasks;
 using aweXpect.Core;
 using aweXpect.Core.Helpers;
@@ -70,7 +71,7 @@ public ValueTask<bool>
 		public Task<bool>
 #endif
 			AreConsideredEqual(string? actual, string? expected, bool ignoreCase,
-				IEqualityComparer<string> comparer)
+				IEqualityComparer<string>? comparer)
 		{
 			if (actual is null && expected is null)
 			{
@@ -90,10 +91,19 @@ public Task<bool>
 #endif
 			}
 
+			if (comparer is not null)
+			{
+#if NET8_0_OR_GREATER
+				return ValueTask.FromResult(Contains(actual, expected, comparer));
+#else
+				return Task.FromResult(Contains(actual, expected, comparer));
+#endif
+			}
+
 #if NET8_0_OR_GREATER
-			return ValueTask.FromResult(Contains(actual, expected, comparer));
+			return ValueTask.FromResult(actual.Contains(expected, ignoreCase ? StringComparison.OrdinalIgnoreCase : StringComparison.Ordinal));
 #else
-			return Task.FromResult(Contains(actual, expected, comparer));
+			return Task.FromResult(actual.Contains(expected, ignoreCase ? StringComparison.OrdinalIgnoreCase : StringComparison.Ordinal));
 #endif
 		}