refactor: fix nullability of nodes Add{Async}Mapping

Source/aweXpect.Core/Core/ExpectationBuilder.cs

@@ -203,7 +203,7 @@ public MemberExpectationBuilder<TSource, TTarget> ForMember<TSource, TTarget>(
 			}
 
 			Node root = _node;
-			_node = _node.AddMapping(memberAccessor, expectationTextGenerator) ?? _node;
+			_node = _node.AddMapping(memberAccessor, expectationTextGenerator);
 			if (replaceIt)
 			{
 				_it = memberAccessor.ToString().Trim();
@@ -247,7 +247,7 @@ public MemberExpectationBuilder<TSource, TTarget> ForAsyncMember<TSource, TTarge
 			}
 
 			Node root = _node;
-			_node = _node.AddAsyncMapping(memberAccessor, expectationTextGenerator) ?? _node;
+			_node = _node.AddAsyncMapping(memberAccessor, expectationTextGenerator);
 			if (replaceIt)
 			{
 				_it = memberAccessor.ToString().Trim();

Source/aweXpect.Core/Core/ManualExpectationBuilder.cs

@@ -17,7 +17,8 @@ namespace aweXpect.Core;
 public class ManualExpectationBuilder<TValue>(
 	ExpectationBuilder? inner,
 	ExpectationGrammars grammars = ExpectationGrammars.None)
-	: ExpectationBuilder("", grammars), IEqualityComparer<ManualExpectationBuilder<TValue>>
+	: ExpectationBuilder("", grammars),
+		IEqualityComparer<ManualExpectationBuilder<TValue>>
 {
 	/// <inheritdoc cref="IEqualityComparer{T}.Equals(T, T)" />
 	public bool Equals(ManualExpectationBuilder<TValue>? x, ManualExpectationBuilder<TValue>? y)

Source/aweXpect.Core/Core/MemberAccessor.cs

@@ -67,8 +67,7 @@ public static MemberAccessor<TSource, TTarget> FromFuncAsMemberAccessor(
 	public override bool Equals(object? obj) => obj is MemberAccessor<TSource, TTarget> other && Equals(other);
 
 	private bool Equals(MemberAccessor<TSource, TTarget> other)
-		=> ToString().Equals(other.ToString()) &&
-		   _accessor.ToString()?.Equals(other._accessor.ToString()) == true;
+		=> ToString().Equals(other.ToString());
 
 	/// <inheritdoc cref="object.GetHashCode()" />
 	public override int GetHashCode() => ToString().GetHashCode();

Source/aweXpect.Core/Core/Nodes/AndNode.cs

@@ -29,14 +29,14 @@ public override void AddConstraint(IConstraint constraint)
 		=> Current.AddConstraint(constraint);
 
 	/// <inheritdoc />
-	public override Node? AddMapping<TValue, TTarget>(MemberAccessor<TValue, TTarget> memberAccessor,
+	public override Node AddMapping<TValue, TTarget>(MemberAccessor<TValue, TTarget> memberAccessor,
 		Action<MemberAccessor, StringBuilder>? expectationTextGenerator = null)
 		where TValue : default
 		where TTarget : default
 		=> Current.AddMapping(memberAccessor, expectationTextGenerator);
 
 	/// <inheritdoc />
-	public override Node? AddAsyncMapping<TValue, TTarget>(
+	public override Node AddAsyncMapping<TValue, TTarget>(
 		MemberAccessor<TValue, Task<TTarget>> memberAccessor,
 		Action<MemberAccessor, StringBuilder>? expectationTextGenerator = null)
 		where TValue : default

Source/aweXpect.Core/Core/Nodes/ExpectationNode.cs

@@ -37,7 +37,7 @@ public override void AddConstraint(IConstraint constraint)
 	}
 
 	/// <inheritdoc />
-	public override Node? AddMapping<TValue, TTarget>(MemberAccessor<TValue, TTarget> memberAccessor,
+	public override Node AddMapping<TValue, TTarget>(MemberAccessor<TValue, TTarget> memberAccessor,
 		Action<MemberAccessor, StringBuilder>? expectationTextGenerator = null)
 		where TValue : default
 		where TTarget : default
@@ -50,7 +50,7 @@ public override void AddConstraint(IConstraint constraint)
 	}
 
 	/// <inheritdoc />
-	public override Node? AddAsyncMapping<TValue, TTarget>(
+	public override Node AddAsyncMapping<TValue, TTarget>(
 		MemberAccessor<TValue, Task<TTarget>> memberAccessor,
 		Action<MemberAccessor, StringBuilder>? expectationTextGenerator = null)
 		where TValue : default

Source/aweXpect.Core/Core/Nodes/Node.cs

@@ -20,14 +20,14 @@ internal abstract class Node
 	///     Add a mapping constraint which maps the value according to the <paramref name="memberAccessor" /> to a member
 	///     and applies this value to the inner expectations.
 	/// </summary>
-	public abstract Node? AddMapping<TValue, TTarget>(MemberAccessor<TValue, TTarget> memberAccessor,
+	public abstract Node AddMapping<TValue, TTarget>(MemberAccessor<TValue, TTarget> memberAccessor,
 		Action<MemberAccessor, StringBuilder>? expectationTextGenerator = null);
 
 	/// <summary>
 	///     Add a mapping constraint which maps the value according to the <paramref name="memberAccessor" /> asynchronously
 	///     to a member and applies this value to the inner expectations.
 	/// </summary>
-	public abstract Node? AddAsyncMapping<TValue, TTarget>(
+	public abstract Node AddAsyncMapping<TValue, TTarget>(
 		MemberAccessor<TValue, Task<TTarget>> memberAccessor,
 		Action<MemberAccessor, StringBuilder>? expectationTextGenerator = null);
 

Source/aweXpect.Core/Core/Nodes/OrNode.cs

@@ -29,14 +29,14 @@ public override void AddConstraint(IConstraint constraint)
 		=> Current.AddConstraint(constraint);
 
 	/// <inheritdoc />
-	public override Node? AddMapping<TValue, TTarget>(MemberAccessor<TValue, TTarget> memberAccessor,
+	public override Node AddMapping<TValue, TTarget>(MemberAccessor<TValue, TTarget> memberAccessor,
 		Action<MemberAccessor, StringBuilder>? expectationTextGenerator = null)
 		where TValue : default
 		where TTarget : default
 		=> Current.AddMapping(memberAccessor, expectationTextGenerator);
 
 	/// <inheritdoc />
-	public override Node? AddAsyncMapping<TValue, TTarget>(
+	public override Node AddAsyncMapping<TValue, TTarget>(
 		MemberAccessor<TValue, Task<TTarget>> memberAccessor,
 		Action<MemberAccessor, StringBuilder>? expectationTextGenerator = null)
 		where TValue : default

Source/aweXpect.Core/Core/Nodes/WhichNode.cs

@@ -43,19 +43,19 @@ public override void AddConstraint(IConstraint constraint)
 		=> _inner?.AddConstraint(constraint);
 
 	/// <inheritdoc />
-	public override Node? AddMapping<TValue, TTarget>(MemberAccessor<TValue, TTarget> memberAccessor,
+	public override Node AddMapping<TValue, TTarget>(MemberAccessor<TValue, TTarget> memberAccessor,
 		Action<MemberAccessor, StringBuilder>? expectationTextGenerator = null)
 		where TValue : default
 		where TTarget : default
-		=> _inner?.AddMapping(memberAccessor, expectationTextGenerator);
+		=> _inner?.AddMapping(memberAccessor, expectationTextGenerator) ?? this;
 
 	/// <inheritdoc />
-	public override Node? AddAsyncMapping<TValue, TTarget>(
+	public override Node AddAsyncMapping<TValue, TTarget>(
 		MemberAccessor<TValue, Task<TTarget>> memberAccessor,
 		Action<MemberAccessor, StringBuilder>? expectationTextGenerator = null)
 		where TValue : default
 		where TTarget : default
-		=> _inner?.AddAsyncMapping(memberAccessor, expectationTextGenerator);
+		=> _inner?.AddAsyncMapping(memberAccessor, expectationTextGenerator) ?? this;
 
 	/// <inheritdoc />
 	public override void AddNode(Node node, string? separator = null)

Tests/aweXpect.Core.Tests/Core/ExpectationBuilderTests.cs

@@ -6,6 +6,26 @@ namespace aweXpect.Core.Tests.Core;
 
 public class ExpectationBuilderTests
 {
+	[Fact]
+	public async Task ForAsyncMember_ShouldUseAndResetExpectationGrammars()
+	{
+		ManualExpectationBuilder<string> sut = new(null);
+		ExpectationGrammars usedExpectationGrammars = ExpectationGrammars.None;
+
+		sut.ForAsyncMember(MemberAccessor<string, Task<int>>.FromFunc(x => Task.FromResult(x.Length), "length "))
+			.AddExpectations(expectationBuilder => expectationBuilder.AddConstraint((_, g)
+				=>
+			{
+				usedExpectationGrammars = g;
+				return new DummyConstraint<int>(v => v == 2, "equal to 2");
+			}), _ => ExpectationGrammars.Nested);
+
+		await sut.IsMetBy("bar", null!, CancellationToken.None);
+
+		await That(usedExpectationGrammars).IsEqualTo(ExpectationGrammars.Nested);
+		await That(sut.ExpectationGrammars).IsEqualTo(ExpectationGrammars.None);
+	}
+
 	[Fact]
 	public async Task ForAsyncMember_WithFailingExpectation_ShouldReturnFailureConstraintResult()
 	{
@@ -36,6 +56,42 @@ public async Task ForAsyncMember_WithSucceedingExpectation_ShouldReturnSuccessCo
 		await That(constraintResult.GetExpectationText()).IsEqualTo("length equal to 3");
 	}
 
+	[Fact]
+	public async Task ForAsyncMember_WithValidation_ShouldIncludeValidation()
+	{
+		ManualExpectationBuilder<string> sut = new(null);
+
+		sut.ForAsyncMember(MemberAccessor<string, Task<int>>.FromFunc(x => Task.FromResult(x.Length), "length "))
+			.Validate((_, _) => new DummyConstraint<string>(_ => false, "validated and "))
+			.AddExpectations(expectationBuilder => expectationBuilder.AddConstraint((_, _)
+				=> new DummyConstraint<int>(v => v == 3, "equal to 3")));
+
+		ConstraintResult constraintResult = await sut.IsMetBy("bar", null!, CancellationToken.None);
+
+		await That(constraintResult.Outcome).IsEqualTo(Outcome.Failure);
+		await That(constraintResult.GetExpectationText()).IsEqualTo("validated and length equal to 3");
+	}
+
+	[Fact]
+	public async Task ForMember_ShouldUseAndResetExpectationGrammars()
+	{
+		ManualExpectationBuilder<string> sut = new(null);
+		ExpectationGrammars usedExpectationGrammars = ExpectationGrammars.None;
+
+		sut.ForMember(MemberAccessor<string, int>.FromFunc(x => x.Length, "length "))
+			.AddExpectations(expectationBuilder => expectationBuilder.AddConstraint((_, g)
+				=>
+			{
+				usedExpectationGrammars = g;
+				return new DummyConstraint<int>(v => v == 2, "equal to 2");
+			}), _ => ExpectationGrammars.Nested);
+
+		await sut.IsMetBy("bar", null!, CancellationToken.None);
+
+		await That(usedExpectationGrammars).IsEqualTo(ExpectationGrammars.Nested);
+		await That(sut.ExpectationGrammars).IsEqualTo(ExpectationGrammars.None);
+	}
+
 	[Fact]
 	public async Task ForMember_WithFailingExpectation_ShouldReturnFailureConstraintResult()
 	{
@@ -66,6 +122,22 @@ public async Task ForMember_WithSucceedingExpectation_ShouldReturnSuccessConstra
 		await That(constraintResult.GetExpectationText()).IsEqualTo("length equal to 3");
 	}
 
+	[Fact]
+	public async Task ForMember_WithValidation_ShouldIncludeValidation()
+	{
+		ManualExpectationBuilder<string> sut = new(null);
+
+		sut.ForMember(MemberAccessor<string, int>.FromFunc(x => x.Length, "length "))
+			.Validate((_, _) => new DummyConstraint<string>(_ => false, "validated and "))
+			.AddExpectations(expectationBuilder => expectationBuilder.AddConstraint((_, _)
+				=> new DummyConstraint<int>(v => v == 3, "equal to 3")));
+
+		ConstraintResult constraintResult = await sut.IsMetBy("bar", null!, CancellationToken.None);
+
+		await That(constraintResult.Outcome).IsEqualTo(Outcome.Failure);
+		await That(constraintResult.GetExpectationText()).IsEqualTo("validated and length equal to 3");
+	}
+
 	[Fact]
 	public async Task WhenSubjectHasMultipleLines_ShouldTrimCommonWhiteSpace()
 	{

Tests/aweXpect.Core.Tests/Core/ExpectationGrammarsExtensionsTests.cs

@@ -0,0 +1,55 @@
+namespace aweXpect.Core.Tests.Core;
+
+public sealed class ExpectationGrammarsExtensionsTests
+{
+	[Theory]
+	[InlineData(ExpectationGrammars.None, false)]
+	[InlineData(ExpectationGrammars.Negated, true)]
+	[InlineData(ExpectationGrammars.Plural | ExpectationGrammars.Negated, true)]
+	[InlineData(ExpectationGrammars.Nested | ExpectationGrammars.Plural, false)]
+	[InlineData(ExpectationGrammars.Nested | ExpectationGrammars.Plural | ExpectationGrammars.Negated, true)]
+	public async Task IsNegated_ShouldReturnExpectedValue(ExpectationGrammars input, bool expected)
+	{
+		bool result = input.IsNegated();
+
+		await That(result).IsEqualTo(expected);
+	}
+
+	[Theory]
+	[InlineData(ExpectationGrammars.None, false)]
+	[InlineData(ExpectationGrammars.Nested, true)]
+	[InlineData(ExpectationGrammars.Plural | ExpectationGrammars.Nested, true)]
+	[InlineData(ExpectationGrammars.Negated | ExpectationGrammars.Plural, false)]
+	[InlineData(ExpectationGrammars.Nested | ExpectationGrammars.Plural | ExpectationGrammars.Negated, true)]
+	public async Task IsNested_ShouldReturnExpectedValue(ExpectationGrammars input, bool expected)
+	{
+		bool result = input.IsNested();
+
+		await That(result).IsEqualTo(expected);
+	}
+
+	[Theory]
+	[InlineData(ExpectationGrammars.None, false)]
+	[InlineData(ExpectationGrammars.Plural, true)]
+	[InlineData(ExpectationGrammars.Plural | ExpectationGrammars.Nested, true)]
+	[InlineData(ExpectationGrammars.Negated | ExpectationGrammars.Nested, false)]
+	[InlineData(ExpectationGrammars.Nested | ExpectationGrammars.Plural | ExpectationGrammars.Negated, true)]
+	public async Task IsPlural_ShouldReturnExpectedValue(ExpectationGrammars input, bool expected)
+	{
+		bool result = input.IsPlural();
+
+		await That(result).IsEqualTo(expected);
+	}
+
+	[Theory]
+	[InlineData(ExpectationGrammars.None, ExpectationGrammars.Negated)]
+	[InlineData(ExpectationGrammars.Plural, ExpectationGrammars.Plural | ExpectationGrammars.Negated)]
+	[InlineData(ExpectationGrammars.Nested | ExpectationGrammars.Plural,
+		ExpectationGrammars.Nested | ExpectationGrammars.Plural | ExpectationGrammars.Negated)]
+	public async Task Negate_ShouldAddNegated(ExpectationGrammars input, ExpectationGrammars expected)
+	{
+		ExpectationGrammars result = input.Negate();
+
+		await That(result).IsEqualTo(expected);
+	}
+}

Tests/aweXpect.Core.Tests/Core/ManualExpectationBuilderTests.cs

@@ -113,6 +113,28 @@ public async Task Equals_WithSelf_ShouldBeTrue()
 		await That(result).IsTrue();
 	}
 
+	[Fact]
+	public async Task GetHashCode_DifferentConstraint_ShouldNotBeEqual()
+	{
+		ManualExpectationBuilder<int> sut1 = new(null);
+		sut1.AddConstraint((_, _, _) => new DummyConstraint("foo"));
+		ManualExpectationBuilder<int> sut2 = new(null);
+		sut2.ForWhich<int, int>(x => x)
+			.AddConstraint((_, _, _) => new DummyConstraint("foo"));
+
+		await That(sut1.GetHashCode()).IsNotEqualTo(sut2.GetHashCode());
+	}
+
+	[Fact]
+	public async Task GetHashCode_SameConstraint_ShouldBeEqual()
+	{
+		ManualExpectationBuilder<int> sut1 = new(null);
+		sut1.AddConstraint((_, _, _) => new DummyConstraint("foo"));
+		ManualExpectationBuilder<int> sut2 = new(null);
+		sut2.AddConstraint((_, _, _) => new DummyConstraint("foo"));
+
+		await That(sut1.GetHashCode()).IsEqualTo(sut2.GetHashCode());
+	}
 
 	[Fact]
 	public async Task IsMet_ShouldThrowNotSupportedException()

Tests/aweXpect.Core.Tests/Core/MemberAccessorTests.cs

@@ -2,6 +2,50 @@
 
 public sealed class MemberAccessorTests
 {
+	[Theory]
+	[InlineData(".Length ", true)]
+	[InlineData(".SomethingElse ", false)]
+	public async Task Equals_ShouldCompareStringRepresentation(string otherStringRepresentation, bool expectedResult)
+	{
+		MemberAccessor<string, int> sut = MemberAccessor<string, int>.FromExpression(x => x.Length);
+		MemberAccessor<string, int> other =
+			MemberAccessor<string, int>.FromFunc(x => x.Length, otherStringRepresentation);
+
+		bool result = sut.Equals(other);
+
+		await That(result).IsEqualTo(expectedResult);
+	}
+
+	[Fact]
+	public async Task Equals_ToNull_ShouldBeFalse()
+	{
+		MemberAccessor<string, int> sut = MemberAccessor<string, int>.FromExpression(x => x.Length);
+
+		bool result = sut.Equals(null);
+
+		await That(result).IsFalse();
+	}
+
+	[Fact]
+	public async Task Equals_ToOtherObject_ShouldBeFalse()
+	{
+		MemberAccessor<string, int> sut = MemberAccessor<string, int>.FromExpression(x => x.Length);
+		object other = MemberAccessor<string, string>.FromExpression(x => x);
+
+		bool result = sut.Equals(other);
+
+		await That(result).IsFalse();
+	}
+
+	[Fact]
+	public async Task FromExpression_ShouldCompileExpression()
+	{
+		MemberAccessor<string, int> subject = MemberAccessor<string, int>
+			.FromExpression(x => x.Length);
+
+		await That(subject.AccessMember("foo")).IsEqualTo(3);
+	}
+
 	[Fact]
 	public async Task FromExpression_ShouldGetMemberPath()
 	{
@@ -36,4 +80,22 @@ public async Task FromFuncAsMemberAccessor_ShouldTryToExtractMemberAccessor(stri
 
 		await That(subject.ToString()).IsEqualTo(expected);
 	}
+
+	[Fact]
+	public async Task GetHashCode_DifferentConstraint_ShouldNotBeEqual()
+	{
+		MemberAccessor<string, int> sut1 = MemberAccessor<string, int>.FromFunc(x => x.Length, "foo");
+		MemberAccessor<string, int> sut2 = MemberAccessor<string, int>.FromFunc(x => x.Length, "bar");
+
+		await That(sut1.GetHashCode()).IsNotEqualTo(sut2.GetHashCode());
+	}
+
+	[Fact]
+	public async Task GetHashCode_SameConstraint_ShouldBeEqual()
+	{
+		MemberAccessor<string, int> sut1 = MemberAccessor<string, int>.FromFunc(x => x.Length, "foo");
+		MemberAccessor<string, int> sut2 = MemberAccessor<string, int>.FromFunc(x => x.Length, "foo");
+
+		await That(sut1.GetHashCode()).IsEqualTo(sut2.GetHashCode());
+	}
 }