public void WriteCharArray_AcrossMultipleBuffers()
{
var bufferWriter = new TestMemoryBufferWriter(2);
var textWriter = new Utf8BufferTextWriter();
textWriter.SetWriter(bufferWriter);
var chars = "Hello world".ToCharArray();
textWriter.Write(chars);
textWriter.Flush();
var segments = bufferWriter.GetSegments();
Assert.Equal(6, segments.Count);
Assert.Equal(1, bufferWriter.Position);
Assert.Equal((byte)'H', segments[0].Span[0]);
Assert.Equal((byte)'e', segments[0].Span[1]);
Assert.Equal((byte)'l', segments[1].Span[0]);
Assert.Equal((byte)'l', segments[1].Span[1]);
Assert.Equal((byte)'o', segments[2].Span[0]);
Assert.Equal((byte)' ', segments[2].Span[1]);
Assert.Equal((byte)'w', segments[3].Span[0]);
Assert.Equal((byte)'o', segments[3].Span[1]);
Assert.Equal((byte)'r', segments[4].Span[0]);
Assert.Equal((byte)'l', segments[4].Span[1]);
Assert.Equal((byte)'d', segments[5].Span[0]);
}
private void WriteMultiByteCharactersToSmallBuffers()
{
// Test string breakdown (char => UTF-8 hex values):
// a => 61
// い => E3-81-84
// b => 62
// ろ => E3-82-8D
// c => 63
// d => 64
// は => E3-81-AF
// に => E3-81-AB
// e => 65
// ほ => E3-81-BB
// f => 66
// へ => E3-81-B8
// ど => E3-81-A9
// g => 67
// h => 68
// i => 69
// \uD800\uDC00 => F0-90-80-80 (this is a surrogate pair that is represented as a single 4-byte UTF-8 encoding)
const string testString = "aいbろcdはにeほfへどghi\uD800\uDC00";
// By mixing single byte and multi-byte characters, we know that there will
// be spaces in the active segment that cannot fit the current character. This
// means we'll be testing the GetMemory(minimumSize) logic.
var bufferWriter = new TestMemoryBufferWriter(segmentSize: 5);
var writer = new Utf8BufferTextWriter();
writer.SetWriter(bufferWriter);
writer.Write(testString);
writer.Flush();
// Verify the output
var allSegments = bufferWriter.GetSegments().Select(s => s.ToArray()).ToArray();
Assert.Collection(allSegments,
seg => Assert.Equal(new byte[] { 0x61, 0xE3, 0x81, 0x84, 0x62 }, seg), // "aいb"
seg => Assert.Equal(new byte[] { 0xE3, 0x82, 0x8D, 0x63, 0x64 }, seg), // "ろcd"
seg => Assert.Equal(new byte[] { 0xE3, 0x81, 0xAF }, seg), // "は"
seg => Assert.Equal(new byte[] { 0xE3, 0x81, 0xAB, 0x65 }, seg), // "にe"
seg => Assert.Equal(new byte[] { 0xE3, 0x81, 0xBB, 0x66 }, seg), // "ほf"
seg => Assert.Equal(new byte[] { 0xE3, 0x81, 0xB8 }, seg), // "へ"
seg => Assert.Equal(new byte[] { 0xE3, 0x81, 0xA9, 0x67, 0x68 }, seg), // "どgh"
seg => Assert.Equal(new byte[] { 0x69, 0xF0, 0x90, 0x80, 0x80 }, seg)); // "i\uD800\uDC00"
Assert.Equal(testString, Encoding.UTF8.GetString(bufferWriter.ToArray()));
}