public void EncodeUtf8_EmptyInput_AlwaysSucceeds()
{
// Arrange
var encoder = new ConfigurableScalarTextEncoder(_ => false /* disallow everything */);
// Act & assert
Assert.Equal(OperationStatus.Done, encoder.EncodeUtf8(ReadOnlySpan <byte> .Empty, Span <byte> .Empty, out int bytesConsumed, out int bytesWritten, isFinalBlock: true));
Assert.Equal(0, bytesConsumed);
Assert.Equal(0, bytesWritten);
Assert.Equal(OperationStatus.Done, encoder.EncodeUtf8(ReadOnlySpan <byte> .Empty, Span <byte> .Empty, out bytesConsumed, out bytesWritten, isFinalBlock: false));
Assert.Equal(0, bytesConsumed);
Assert.Equal(0, bytesWritten);
}
public void EncodeUtf8_WellFormedInput_DoesNotRequireEncoding_CopiedToDestinationCorrectly(int destinationSize, int expectedBytesCopied)
{
// This test considers input which is well-formed and doesn't need to be encoded.
// If the destination buffer is large enough, the data should be copied in its entirety.
// If the destination buffer is too small, only complete UTF-8 subsequences should be copied.
// We should never copy a partial subsequence, as it would cause a future call to EncodeUtf8
// to misinterpret the data as ill-formed.
// Arrange
byte[] fullUtf8Input = new byte[] {
0xC2, 0x82,
0x40,
0xE2, 0x90, 0x91,
0xF3, 0xA0, 0xA1, 0xA2,
0x50
}; // UTF-8 subsequences of varying length
var encoder = new ConfigurableScalarTextEncoder(_ => true /* allow everything */);
// Act & assert
OperationStatus expectedOpStatus = (expectedBytesCopied == fullUtf8Input.Length) ? OperationStatus.Done : OperationStatus.DestinationTooSmall;
byte[] destination = new byte[destinationSize];
Assert.Equal(expectedOpStatus, encoder.EncodeUtf8(fullUtf8Input, destination, out int bytesConsumed, out int bytesWritten, isFinalBlock: true));
Assert.Equal(expectedBytesCopied, bytesConsumed);
Assert.Equal(expectedBytesCopied, bytesWritten); // bytes written should match bytes consumed if no encoding needs to take place
Assert.Equal(fullUtf8Input.AsSpan(0, bytesConsumed).ToArray(), destination.AsSpan(0, bytesWritten).ToArray()); // ensure byte-for-byte copy
Assert.True(destination.AsSpan(bytesWritten).ToArray().All(el => el == 0)); // all remaining bytes should be unchanged
destination = new byte[destinationSize];
Assert.Equal(expectedOpStatus, encoder.EncodeUtf8(fullUtf8Input, destination, out bytesConsumed, out bytesWritten, isFinalBlock: false));
Assert.Equal(expectedBytesCopied, bytesConsumed);
Assert.Equal(expectedBytesCopied, bytesWritten); // bytes written should match bytes consumed if no encoding needs to take place
Assert.Equal(fullUtf8Input.AsSpan(0, bytesConsumed).ToArray(), destination.AsSpan(0, bytesWritten).ToArray()); // ensure byte-for-byte copy
Assert.True(destination.AsSpan(bytesWritten).ToArray().All(el => el == 0)); // all remaining bytes should be unchanged
}
public void EncodeUtf8_MixedInputWhichRequiresEncodingOrReplacement()
{
// Arrange
var fullInput = new[]
{
new { utf8Bytes = new byte[] { 0x40 }, output = "@" },
new { utf8Bytes = new byte[] { 0xC3, 0x85 }, output = "[00C5]" }, // U+00C5 LATIN CAPITAL LETTER A WITH RING ABOVE (encoded since odd scalar value)
new { utf8Bytes = new byte[] { 0xC3, 0x86 }, output = "\u00C6" }, // U+00C6 LATIN CAPITAL LETTER AE (on allow list)
new { utf8Bytes = new byte[] { 0xFF }, output = "[FFFD]" }, // (invalid UTF-8, replaced with encoded form of U+FFFD)
new { utf8Bytes = new byte[] { 0xEF, 0xBF, 0xBD }, output = "[FFFD]" }, // U+FFFD REPLACEMENT CHARACTER (encoded since not on allow list)
new { utf8Bytes = new byte[] { 0xF0, 0x90, 0x82, 0x82 }, output = "\U00010082" }, // U+10082 LINEAR B IDEOGRAM B104 DEER (not encoded since on allow list)
new { utf8Bytes = new byte[] { 0xF0, 0x90, 0x82, 0x83 }, output = "[10083]" }, // U+10083 LINEAR B IDEOGRAM B105 EQUID (encoded since not on allow list)
};
var encoder = new ConfigurableScalarTextEncoder(scalarValue => (scalarValue % 2) == 0 /* allow only even-valued scalars to be represented unescaped */);
// Act & assert
List <byte> aggregateInputBytesSoFar = new List <byte>();
List <byte> expectedOutputBytesSoFar = new List <byte>();
foreach (var entry in fullInput)
{
int aggregateInputByteCountAtStartOfLoop = aggregateInputBytesSoFar.Count;
byte[] destination;
int bytesConsumed, bytesWritten;
for (int i = 0; i < entry.utf8Bytes.Length - 1; i++)
{
aggregateInputBytesSoFar.Add(entry.utf8Bytes[i]);
// If not final block, partial encoding should say "needs more data".
// We'll try with various destination lengths just to make sure it doesn't affect result.
foreach (int destinationLength in new[] { expectedOutputBytesSoFar.Count, expectedOutputBytesSoFar.Count + 1024 })
{
destination = new byte[destinationLength];
Assert.Equal(OperationStatus.NeedMoreData, encoder.EncodeUtf8(aggregateInputBytesSoFar.ToArray(), destination, out bytesConsumed, out bytesWritten, isFinalBlock: false));
Assert.Equal(aggregateInputByteCountAtStartOfLoop, bytesConsumed);
Assert.Equal(expectedOutputBytesSoFar.Count, bytesWritten);
Assert.Equal(expectedOutputBytesSoFar.ToArray(), new Span <byte>(destination, 0, expectedOutputBytesSoFar.Count).ToArray());
}
// Now try it with "isFinalBlock = true" to force the U+FFFD conversion
destination = new byte[expectedOutputBytesSoFar.Count]; // first with not enough output space to write "[FFFD]"
Assert.Equal(OperationStatus.DestinationTooSmall, encoder.EncodeUtf8(aggregateInputBytesSoFar.ToArray(), destination, out bytesConsumed, out bytesWritten, isFinalBlock: true));
Assert.Equal(aggregateInputByteCountAtStartOfLoop, bytesConsumed);
Assert.Equal(expectedOutputBytesSoFar.Count, bytesWritten);
Assert.Equal(expectedOutputBytesSoFar.ToArray(), new Span <byte>(destination, 0, expectedOutputBytesSoFar.Count).ToArray());
destination = new byte[expectedOutputBytesSoFar.Count + 1024]; // then with enough output space to write "[FFFD]"
Assert.Equal(OperationStatus.Done, encoder.EncodeUtf8(aggregateInputBytesSoFar.ToArray(), destination, out bytesConsumed, out bytesWritten, isFinalBlock: true));
Assert.Equal(aggregateInputBytesSoFar.Count, bytesConsumed);
Assert.Equal(expectedOutputBytesSoFar.Count + "[FFFD]".Length, bytesWritten);
Assert.Equal(expectedOutputBytesSoFar.Concat(Encoding.UTF8.GetBytes("[FFFD]")).ToArray(), new Span <byte>(destination, 0, expectedOutputBytesSoFar.Count + "[FFFD]".Length).ToArray());
}
// Consume the remainder of this entry and make sure it escaped properly (if needed).
aggregateInputBytesSoFar.Add(entry.utf8Bytes.Last());
// First with not enough space in the destination buffer.
destination = new byte[expectedOutputBytesSoFar.Count + Encoding.UTF8.GetByteCount(entry.output) - 1];
Assert.Equal(OperationStatus.DestinationTooSmall, encoder.EncodeUtf8(aggregateInputBytesSoFar.ToArray(), destination, out bytesConsumed, out bytesWritten, isFinalBlock: true));
Assert.Equal(aggregateInputByteCountAtStartOfLoop, bytesConsumed);
Assert.Equal(expectedOutputBytesSoFar.Count, bytesWritten);
Assert.Equal(expectedOutputBytesSoFar.ToArray(), new Span <byte>(destination, 0, expectedOutputBytesSoFar.Count).ToArray());
// Then with exactly enough space in the destination buffer,
// and again with more than enough space in the destination buffer.
expectedOutputBytesSoFar.AddRange(Encoding.UTF8.GetBytes(entry.output));
foreach (int destinationLength in new[] { expectedOutputBytesSoFar.Count, expectedOutputBytesSoFar.Count + 1024 })
{
destination = new byte[destinationLength];
Assert.Equal(OperationStatus.Done, encoder.EncodeUtf8(aggregateInputBytesSoFar.ToArray(), destination, out bytesConsumed, out bytesWritten, isFinalBlock: false));
Assert.Equal(aggregateInputBytesSoFar.Count, bytesConsumed);
Assert.Equal(expectedOutputBytesSoFar.Count, bytesWritten);
Assert.Equal(expectedOutputBytesSoFar.ToArray(), new Span <byte>(destination, 0, expectedOutputBytesSoFar.Count).ToArray());
}
}
}