feat: trim common white-space from subject

Pipeline/Build.cs

@@ -19,7 +19,7 @@ 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;
 

Source/aweXpect.Core/Core/ExpectationBuilder.cs

@@ -44,7 +44,7 @@ public abstract class ExpectationBuilder
 	protected ExpectationBuilder(string subjectExpression, ExpectationGrammars grammars = ExpectationGrammars.None)
 	{
 		AweXpectInitialization.EnsureInitialized();
-		Subject = subjectExpression;
+		Subject = subjectExpression.TrimCommonWhiteSpace();
 		ExpectationGrammars = grammars;
 	}
 

Source/aweXpect.Core/Core/Helpers/StringExtensions.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Diagnostics.CodeAnalysis;
 using System.Linq;
+using System.Text;
 
 namespace aweXpect.Core.Helpers;
 
@@ -90,4 +91,54 @@ public static string SubstringUntilFirst(this string name, char c)
 		const char ellipsis = '\u2026';
 		return $"{value.Substring(0, indexOfWordBoundary)}{ellipsis}";
 	}
+
+	public static string TrimCommonWhiteSpace(this string value)
+	{
+		string[] lines = value.Split('\n');
+		if (lines.Length <= 1)
+		{
+			return value;
+		}
+
+		StringBuilder sb = new();
+		foreach (char c in lines[1])
+		{
+			if (char.IsWhiteSpace(c))
+			{
+				sb.Append(c);
+			}
+			else
+			{
+				break;
+			}
+		}
+
+		string commonWhiteSpace = sb.ToString();
+
+		for (int l = 2; l < lines.Length; l++)
+		{
+			if (lines[l].StartsWith(commonWhiteSpace))
+			{
+				continue;
+			}
+
+			for (int i = 0; i < Math.Min(lines[l].Length, commonWhiteSpace.Length); i++)
+			{
+				if (lines[l][i] != commonWhiteSpace[i])
+				{
+					commonWhiteSpace = commonWhiteSpace[..i];
+					break;
+				}
+			}
+		}
+
+		sb.Clear();
+		sb.Append(lines[0]);
+		foreach (string? line in lines.Skip(1))
+		{
+			sb.Append('\n').Append(line[commonWhiteSpace.Length..]);
+		}
+
+		return sb.ToString();
+	}
 }

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

@@ -66,6 +66,29 @@ public async Task ForMember_WithSucceedingExpectation_ShouldReturnSuccessConstra
 		await That(constraintResult.GetExpectationText()).IsEqualTo("length equal to 3");
 	}
 
+	[Fact]
+	public async Task WhenSubjectHasMultipleLines_ShouldTrimCommonWhiteSpace()
+	{
+		async Task Act() => await That(new[]
+		{
+			1, 2, 3,
+		}).IsEmpty();
+
+		await That(Act).Throws<XunitException>()
+			.WithMessage("""
+			             Expected that new[]
+			             {
+			             	1, 2, 3,
+			             }
+			             is empty,
+			             but it was [
+			               1,
+			               2,
+			               3
+			             ]
+			             """);
+	}
+
 	[Fact]
 	public async Task WhenTypeImplementsIDescribableSubject_ShouldUseToStringFromIt()
 	{