feat: Add culture for Insert and Append

Author: linkdotnet

src/LinkDotNet.StringBuilder/ValueStringBuilder.Append.cs

@@ -1,3 +1,4 @@
+using System.Globalization;
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
 using System.Text;
@@ -52,10 +53,11 @@ public unsafe void Append(bool value)
     /// <param name="format">Optional formatter. If not provided the default of the given instance is taken.</param>
     /// <param name="bufferSize">Size of the buffer allocated. If you have a custom type that implements <see cref="ISpanFormattable"/> that
     /// requires more space than the default (36 characters), adjust the value.</param>
+    /// <param name="formatProvider">Optional format provider. If null <see cref="CultureInfo.InvariantCulture"/> is used.</param>
     /// <typeparam name="T">Any <see cref="ISpanFormattable"/>.</typeparam>
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    public void Append<T>(T value, scoped ReadOnlySpan<char> format = default, int bufferSize = 36)
-        where T : ISpanFormattable => AppendSpanFormattable(value, format, bufferSize);
+    public void Append<T>(T value, scoped ReadOnlySpan<char> format = default, int bufferSize = 36, IFormatProvider? formatProvider = null)
+        where T : ISpanFormattable => AppendSpanFormattable(value, format, bufferSize, formatProvider);
 
     /// <summary>
     /// Appends a string.
@@ -181,7 +183,7 @@ public Span<char> AppendSpan(int length)
     }
 
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    private void AppendSpanFormattable<T>(T value, scoped ReadOnlySpan<char> format = default, int bufferSize = 36)
+    private void AppendSpanFormattable<T>(T value, scoped ReadOnlySpan<char> format = default, int bufferSize = 36, IFormatProvider? formatProvider = null)
         where T : ISpanFormattable
     {
         var newSize = bufferSize + bufferPosition;
@@ -190,7 +192,7 @@ private void AppendSpanFormattable<T>(T value, scoped ReadOnlySpan<char> format
             EnsureCapacity(newSize);
         }
 
-        if (!value.TryFormat(buffer[bufferPosition..], out var written, format, null))
+        if (!value.TryFormat(buffer[bufferPosition..], out var written, format, formatProvider ?? CultureInfo.InvariantCulture))
         {
             throw new InvalidOperationException($"Could not insert {value} into given buffer. Is the buffer (size: {bufferSize}) large enough?");
         }

src/LinkDotNet.StringBuilder/ValueStringBuilder.Insert.cs

@@ -1,4 +1,5 @@
-using System.Runtime.CompilerServices;
+using System.Globalization;
+using System.Runtime.CompilerServices;
 using System.Text;
 
 namespace LinkDotNet.StringBuilder;
@@ -43,10 +44,11 @@ public void Insert(int index, Rune value)
     /// <param name="value">Formattable span to insert into this builder.</param>
     /// <param name="format">Optional formatter. If not provided the default of the given instance is taken.</param>
     /// <param name="bufferSize">Size of the buffer allocated on the stack.</param>
+    /// <param name="formatProvider">Optional format provider. If null <see cref="CultureInfo.InvariantCulture"/> is used.</param>
     /// <typeparam name="T">Any <see cref="ISpanFormattable"/>.</typeparam>
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    public void Insert<T>(int index, T value, scoped ReadOnlySpan<char> format = default, int bufferSize = 36)
-        where T : ISpanFormattable => InsertSpanFormattable(index, value, format, bufferSize);
+    public void Insert<T>(int index, T value, scoped ReadOnlySpan<char> format = default, int bufferSize = 36, IFormatProvider? formatProvider = null)
+        where T : ISpanFormattable => InsertSpanFormattable(index, value, format, bufferSize, formatProvider);
 
     /// <summary>
     /// Appends the string representation of the boolean to the builder.
@@ -89,7 +91,7 @@ public void Insert(int index, scoped ReadOnlySpan<char> value)
     }
 
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    private void InsertSpanFormattable<T>(int index, T value, scoped ReadOnlySpan<char> format, int bufferSize)
+    private void InsertSpanFormattable<T>(int index, T value, scoped ReadOnlySpan<char> format, int bufferSize, IFormatProvider? formatProvider = null)
         where T : ISpanFormattable
     {
         if (index < 0)
@@ -103,7 +105,7 @@ private void InsertSpanFormattable<T>(int index, T value, scoped ReadOnlySpan<ch
         }
 
         Span<char> tempBuffer = stackalloc char[bufferSize];
-        if (value.TryFormat(tempBuffer, out var written, format, null))
+        if (value.TryFormat(tempBuffer, out var written, format, formatProvider ?? CultureInfo.InvariantCulture))
         {
             var newLength = bufferPosition + written;
             if (newLength > buffer.Length)

tests/LinkDotNet.StringBuilder.UnitTests/ValueStringBuilder.Append.Tests.cs

@@ -1,3 +1,5 @@
+using System.Globalization;
+
 namespace LinkDotNet.StringBuilder.UnitTests;
 
 public class ValueStringBuilderAppendTests
@@ -87,6 +89,34 @@ public void ShouldAppendSpanFormattable()
         builder.ToString().ShouldBe("2.2");
     }
 
+    [Fact]
+    public void ShouldAppendSpanFormattableWithGivenCulture()
+    {
+        using var builder = new ValueStringBuilder();
+
+        builder.Append(1.2m, formatProvider: CultureInfo.GetCultureInfo("de-DE"));
+
+        builder.ToString().ShouldBe("1,2");
+    }
+
+    [Fact]
+    public void ShouldAppendSpanFormattableWithInvariantCultureWhenFormatProviderIsNull()
+    {
+        using var builder = new ValueStringBuilder();
+        var originalCulture = CultureInfo.CurrentCulture;
+        try
+        {
+            CultureInfo.CurrentCulture = CultureInfo.GetCultureInfo("de-DE");
+            builder.Append(1.2m, formatProvider: null);
+        }
+        finally
+        {
+            CultureInfo.CurrentCulture = originalCulture;
+        }
+
+        builder.ToString().ShouldBe("1.2");
+    }
+
     [Fact]
     public void ShouldAppendMultipleChars()
     {

tests/LinkDotNet.StringBuilder.UnitTests/ValueStringBuilder.Insert.Tests.cs

@@ -1,3 +1,5 @@
+using System.Globalization;
+
 namespace LinkDotNet.StringBuilder.UnitTests;
 
 public class ValueStringBuilderInsertTests
@@ -33,6 +35,34 @@ public void ShouldAppendSpanFormattable()
         builder.ToString().ShouldBe("2.2");
     }
 
+    [Fact]
+    public void ShouldInsertSpanFormattableWithGivenCulture()
+    {
+        using var builder = new ValueStringBuilder();
+
+        builder.Insert(0, 1.2m, formatProvider: CultureInfo.GetCultureInfo("de-DE"));
+
+        builder.ToString().ShouldBe("1,2");
+    }
+
+    [Fact]
+    public void ShouldInsertSpanFormattableWithInvariantCultureWhenFormatProviderIsNull()
+    {
+        using var builder = new ValueStringBuilder();
+        var originalCulture = CultureInfo.CurrentCulture;
+        try
+        {
+            CultureInfo.CurrentCulture = CultureInfo.GetCultureInfo("de-DE");
+            builder.Insert(0, 1.2m, formatProvider: null);
+        }
+        finally
+        {
+            CultureInfo.CurrentCulture = originalCulture;
+        }
+
+        builder.ToString().ShouldBe("1.2");
+    }
+
     [Fact]
     public void ShouldThrowWhenIndexIsNegative()
     {