csharp/src/Google.Protobuf.Test/WritingPrimitivesTest.cs

#region Copyright notice and license
// Protocol Buffers - Google's data interchange format
// Copyright 2022 Google Inc.  All rights reserved.
// https://developers.google.com/protocol-buffers/
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
//     * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
//     * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#endregion

using NUnit.Framework;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Google.Protobuf.Test;

internal class WritingPrimitivesTest
{
    [Test]
    public void WriteRawString_IllFormedUnicodeString()
    {
        // See https://codeblog.jonskeet.uk/2014/11/07/when-is-a-string-not-a-string/
        char c1 = '\u0058';
        char c2 = '\ud800';
        char c3 = '\u0059';
        string text = new string(new[] { c1, c2, c3 });
        Span<byte> buffer = new byte[10];
        WriteContext.Initialize(ref buffer, out var context);
        WritingPrimitives.WriteString(ref context.buffer, ref context.state, text);

        // The high surrogate is written out in a "raw" form, surrounded by the ASCII
        // characters.
        byte[] expectedBytes = { 0x5, 0x58, 0xef, 0xbf, 0xbd, 0x59 };
        Assert.AreEqual(expectedBytes, buffer.Slice(0, context.state.position).ToArray());
    }
}