Add GetByteCount(Span) (#261)

Author: SimonCropp

apiCount.include.md

@@ -1 +1 @@
-**API count: 415**
+**API count: 416**

api_list.include.md

@@ -76,7 +76,8 @@
 
 #### Encoding
 
- * `int GetBytes(Encoding, ReadOnlySpan<char>, Span<byte>)` [reference](https://learn.microsoft.com/en-us/dotnet/api/system.text.encoding.getbytes?#system-text-encoding-getbytes(system-readonlyspan((system-char))-system-span((system-byte))))
+ * `int GetByteCount(Encoding, ReadOnlySpan<char>)` [reference](https://learn.microsoft.com/en-us/dotnet/api/system.text.encoding.getbytecount#system-text-encoding-getbytecount(system-readonlyspan((system-char))))
+ * `int GetBytes(Encoding, ReadOnlySpan<char>, Span<byte>)` [reference](https://learn.microsoft.com/en-us/dotnet/api/system.text.encoding.getbytes#system-text-encoding-getbytes(system-readonlyspan((system-char))-system-span((system-byte))))
  * `string GetString(Encoding, ReadOnlySpan<byte>)` [reference](https://learn.microsoft.com/en-us/dotnet/api/system.text.encoding.getstring#system-text-encoding-getstring(system-readonlyspan((system-byte))))
 
 

readme.md

@@ -1212,7 +1212,7 @@ Enable by adding and MSBuild property `PolyGuard`
 
  * `ArgumentException.ThrowIfNullOrEmpty` [reference](https://learn.microsoft.com/en-us/dotnet/api/system.argumentexception.throwifnullorempty)
  * `ArgumentException.ThrowIfNullOrWhiteSpace` [reference](https://learn.microsoft.com/en-us/dotnet/api/system.argumentexception.throwifnullorwhitespace)
- * `ArgumentNullException.ThrowIfNull` [reference](https://learn.microsoft.com/en-us/dotnet/api/system.argumentnullexception.throwifnull?view=net-8.0)
+ * `ArgumentNullException.ThrowIfNull` [reference](https://learn.microsoft.com/en-us/dotnet/api/system.argumentnullexception.throwifnull)
 
 With the equivalent Guard APIs:
 

src/Polyfill/Polyfill_Encoding.cs

@@ -5,49 +5,63 @@
 
 #pragma warning disable
 
-#if FeatureMemory && AllowUnsafeBlocks && !NETCOREAPP2_1_OR_GREATER
+#if FeatureMemory
 
 namespace Polyfills;
 
 using System;
 
 static partial class Polyfill
 {
+#if NETCOREAPP2_0 || NETFRAMEWORK || NETSTANDARD2_0
+    /// <summary>
+    /// When overridden in a derived class, calculates the number of bytes produced by encoding the characters in the specified character span.
+    /// </summary>
+    /// <param name="encoding"></param>
+    /// <param name="chars">The span of characters to encode.</param>
+    /// <returns>The number of bytes produced by encoding the specified character span.</returns>
+    //Link: https://learn.microsoft.com/en-us/dotnet/api/system.text.encoding.getbytecount#system-text-encoding-getbytecount(system-readonlyspan((system-char)))
+    public static int GetByteCount(this Encoding target, ReadOnlySpan<char> chars) =>
+        target.GetByteCount(chars.ToArray());
+#endif
+
+#if AllowUnsafeBlocks && !NETCOREAPP2_1_OR_GREATER
     /// <summary>When overridden in a derived class, encodes into a span of bytes a set of characters from the specified read-only span.</summary>
     /// <param name="chars">The span containing the set of characters to encode.</param>
     /// <param name="bytes">The byte span to hold the encoded bytes.</param>
     /// <returns>The number of encoded bytes.</returns>
-    //Link: https://learn.microsoft.com/en-us/dotnet/api/system.text.encoding.getbytes?#system-text-encoding-getbytes(system-readonlyspan((system-char))-system-span((system-byte)))
-    public static unsafe int GetBytes(this Encoding encoding, ReadOnlySpan<char> chars, Span<byte> bytes)
+    //Link: https://learn.microsoft.com/en-us/dotnet/api/system.text.encoding.getbytes#system-text-encoding-getbytes(system-readonlyspan((system-char))-system-span((system-byte)))
+    public static unsafe int GetBytes(this Encoding target, ReadOnlySpan<char> chars, Span<byte> bytes)
     {
-        if (encoding is null)
+        if (target is null)
         {
-            throw new ArgumentNullException(nameof(encoding));
+            throw new ArgumentNullException(nameof(target));
         }
 
         fixed (char* charsPtr = chars)
         fixed (byte* bytesPtr = bytes)
         {
-            return encoding.GetBytes(charsPtr, chars.Length, bytesPtr, bytes.Length);
+            return target.GetBytes(charsPtr, chars.Length, bytesPtr, bytes.Length);
         }
     }
 
     /// <summary>When overridden in a derived class, decodes all the bytes in the specified byte span into a string.</summary>
     /// <param name="bytes">A read-only byte span to decode to a Unicode string.</param>
     /// <returns>A string that contains the decoded bytes from the provided read-only span.</returns>
     //Link: https://learn.microsoft.com/en-us/dotnet/api/system.text.encoding.getstring#system-text-encoding-getstring(system-readonlyspan((system-byte)))
-    public static unsafe string GetString(this Encoding encoding, ReadOnlySpan<byte> bytes)
+    public static unsafe string GetString(this Encoding target, ReadOnlySpan<byte> bytes)
     {
-        if (encoding is null)
+        if (target is null)
         {
-            throw new ArgumentNullException(nameof(encoding));
+            throw new ArgumentNullException(nameof(target));
         }
 
         fixed (byte* bytesPtr = bytes)
         {
-            return encoding.GetString(bytesPtr, bytes.Length);
+            return target.GetString(bytesPtr, bytes.Length);
         }
     }
+#endif
 }
 
 #endif

src/Tests/PolyfillTests_Encoding.cs

@@ -0,0 +1,40 @@
+partial class PolyfillTests
+{
+#if FeatureMemory
+    [Test]
+    public void Encoding_GetByteCount()
+    {
+        var encoding = Encoding.UTF8;
+        var chars = "Hello, World!".AsSpan();
+        var byteCount = encoding.GetByteCount(chars);
+        Assert.AreEqual(13, byteCount);
+    }
+#endif
+
+#if FeatureMemory && AllowUnsafeBlocks
+
+    [Test]
+    public void Encoding_GetString()
+    {
+        var array = (ReadOnlySpan<byte>)"value"u8.ToArray().AsSpan();
+        var result = Encoding.UTF8.GetString(array);
+        Assert.AreEqual("value", result);
+    }
+
+    [Test]
+    public void Encoding_GetBytes()
+    {
+        var encoding = Encoding.UTF8;
+        var chars = "Hello, World!".AsSpan();
+        var bytes = new byte[encoding.GetByteCount(chars)].AsSpan();
+
+        // Act
+        var byteCount = encoding.GetBytes(chars, bytes);
+
+        // Assert
+        Assert.AreEqual(encoding.GetByteCount(chars), byteCount);
+        Assert.AreEqual(encoding.GetBytes("Hello, World!"), bytes.ToArray());
+    }
+
+#endif
+}

src/Tests/PolyfillTests_Enum.cs

@@ -47,7 +47,6 @@ public void Parse()
     [Test]
     public void TryParse()
     {
-
         var result = EnumPolyfill.TryParse<DayOfWeek>("Sunday".AsSpan(), out var dayOfWeek);
         Assert.AreEqual(DayOfWeek.Sunday, dayOfWeek);
         Assert.True(result);