Fix issue with StringBuilderHelper constructor.

Author: electricessence

Source/Open.Text.csproj

@@ -19,7 +19,7 @@
 		<RepositoryUrl>https://github.com/Open-NET-Libraries/Open.Text</RepositoryUrl>
 		<RepositoryType>git</RepositoryType>
 		<PackageTags>string, span, enum, readonlyspan, text, format, split, trim, equals, trimmed equals, first, last, preceding, following, stringbuilder, extensions, stringcomparable, spancomparable, stringsegment, splitassegment</PackageTags>
-		<Version>7.0.1</Version>
+		<Version>7.0.2</Version>
 		<PackageReleaseNotes></PackageReleaseNotes>
 		<PackageLicenseExpression>MIT</PackageLicenseExpression>
 		<PublishRepositoryUrl>true</PublishRepositoryUrl>

Source/StringBuilderHelper.cs

@@ -24,8 +24,14 @@ public override string ToString()
 	/// <summary>
 	/// Constructs a new <see cref="StringBuilderHelper"/> with the specified <see cref="StringBuilder"/>.
 	/// </summary>
-	public StringBuilderHelper(StringBuilder? sb = default)
-			=> Builder = sb ?? new();
+	public StringBuilderHelper(StringBuilder sb)
+		=> Builder = sb ?? throw new ArgumentNullException(nameof(sb));
+
+	/// <summary>
+	/// Constructs a new <see cref="StringBuilderHelper"/> with a new <see cref="StringBuilder"/>.
+	/// </summary>
+	public StringBuilderHelper()
+		: this(new StringBuilder()) { }
 
 	/// <summary>
 	/// Constructs a new <see cref="StringBuilderHelper"/> with a <see cref="StringBuilder"/> of the <paramref name="initialCapacity"/>.

Tests/StringBuilderTests.cs

@@ -1,4 +1,5 @@
-using System;
+using FluentAssertions;
+using System;
 using System.Linq;
 using System.Text;
 using Xunit;
@@ -244,4 +245,14 @@ public static void TrimChars(string expected, string a, string b, string c, stri
 		sb.Append(a).Append(b).Append(c).Append(d).Trim(" !");
 		Assert.Equal(expected, sb.ToString());
 	}
+
+	[Fact]
+	public static void StringBuilderHelperTest()
+	{
+		StringBuilderHelper sb = new();
+		sb += "Hello";
+		sb += " ";
+		sb += "World";
+		sb.ToString().Should().Be("Hello World");
+	}
 }