Add ArgumentNullException tests.

src/BsDiff/BinaryPatch.cs

@@ -40,8 +40,21 @@ public static class BinaryPatch
 	/// <param name="oldData">The original binary data.</param>
 	/// <param name="newData">The new binary data.</param>
 	/// <param name="output">A <see cref="Stream"/> to which the patch will be written.</param>
-	public static void Create(byte[] oldData, byte[] newData, Stream output) =>
+	public static void Create(byte[] oldData, byte[] newData, Stream output)
+	{
+		// check arguments
+#if NET6_0_OR_GREATER
+		ArgumentNullException.ThrowIfNull(oldData);
+		ArgumentNullException.ThrowIfNull(newData);
+#else
+		if (oldData is null)
+			throw new ArgumentNullException(nameof(oldData));
+		if (newData is null)
+			throw new ArgumentNullException(nameof(newData));
+#endif
+
 		Create(oldData.AsSpan(), newData.AsSpan(), output);
+	}
 
 	/// <summary>
 	/// Creates a binary patch (in <a href="https://www.daemonology.net/bsdiff/">bsdiff</a> format) that can be used

tests/BsDiff.Tests/BinaryPatchTests.cs

@@ -4,6 +4,30 @@ namespace BsDiff.Tests;
 
 public class BinaryPatchTests
 {
+	[Fact]
+	public void CreateNullOldData() =>
+		Assert.Throws<ArgumentNullException>(() => BinaryPatch.Create(null!, Array.Empty<byte>(), new MemoryStream()));
+
+	[Fact]
+	public void CreateNullNewData() =>
+		Assert.Throws<ArgumentNullException>(() => BinaryPatch.Create(Array.Empty<byte>(), null!, new MemoryStream()));
+
+	[Fact]
+	public void CreateNullOutput() =>
+		Assert.Throws<ArgumentNullException>(() => BinaryPatch.Create(Array.Empty<byte>(), Array.Empty<byte>(), null!));
+
+	[Fact]
+	public void ApplyNullInput() =>
+		Assert.Throws<ArgumentNullException>(() => BinaryPatch.Apply(null!, () => new MemoryStream(), new MemoryStream()));
+
+	[Fact]
+	public void ApplyNullCreatePatchStream() =>
+		Assert.Throws<ArgumentNullException>(() => BinaryPatch.Apply(new MemoryStream(), null!, new MemoryStream()));
+
+	[Fact]
+	public void ApplyNullOutput() =>
+		Assert.Throws<ArgumentNullException>(() => BinaryPatch.Apply(new MemoryStream(), () => new MemoryStream(), null!));
+
 	[Fact]
 	public void CreateZeroesPatch()
 	{