Fix base64 deserialization when JSON encoder escapes forward slashes (#1342)

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: stephentoub <2642209+stephentoub@users.noreply.github.com>
This commit is contained in:
Copilot 2026-02-23 14:20:25 -05:00 • committed by GitHub
commit 774a1dba35
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6 changed files with 710 additions and 48 deletions

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@ -1,6 +1,7 @@
using System.Buffers;
using System.Buffers.Text;
using System.Diagnostics;
using System.Diagnostics.CodeAnalysis;
using System.Runtime.InteropServices;
using System.Text.Json.Serialization;
@ -28,7 +29,7 @@ namespace ModelContextProtocol.Protocol;
public sealed class BlobResourceContents : ResourceContents
{
private ReadOnlyMemory<byte>? _decodedData;
private ReadOnlyMemory<byte> _blob;
private ReadOnlyMemory<byte>? _blob;
/// <summary>
/// Creates an <see cref="BlobResourceContents"/> from raw data.
@ -40,15 +41,20 @@ public sealed class BlobResourceContents : ResourceContents
/// <exception cref="InvalidOperationException"></exception>
public static BlobResourceContents FromBytes(ReadOnlyMemory<byte> bytes, string uri, string? mimeType = null)
{
ReadOnlyMemory<byte> blob = EncodingUtilities.EncodeToBase64Utf8(bytes);
return new()
{
_decodedData = bytes,
Blob = blob,
MimeType = mimeType,
Uri = uri
};
return new(bytes, uri, mimeType);
}
/// <summary>Initializes a new instance of the <see cref="BlobResourceContents"/> class.</summary>
public BlobResourceContents()
{
}
[SetsRequiredMembers]
private BlobResourceContents(ReadOnlyMemory<byte> decodedData, string uri, string? mimeType)
{
_decodedData = decodedData;
Uri = uri;
MimeType = mimeType;
}
/// <summary>
@ -60,7 +66,16 @@ public sealed class BlobResourceContents : ResourceContents
[JsonPropertyName("blob")]
public required ReadOnlyMemory<byte> Blob
{
get => _blob;
get
{
if (_blob is null)
{
Debug.Assert(_decodedData is not null);
_blob = EncodingUtilities.EncodeToBase64Utf8(_decodedData!.Value);
}
return _blob.Value;
}
set
{
_blob = value;

View file

@ -92,6 +92,7 @@ public abstract class ContentBlock
string? name = null;
string? title = null;
ReadOnlyMemory<byte>? data = null;
ReadOnlyMemory<byte>? decodedData = null;
string? mimeType = null;
string? uri = null;
string? description = null;
@ -137,7 +138,14 @@ public abstract class ContentBlock
break;
case "data":
data = reader.HasValueSequence ? reader.ValueSequence.ToArray() : reader.ValueSpan.ToArray();
if (!reader.ValueIsEscaped)
{
data = reader.HasValueSequence ? reader.ValueSequence.ToArray() : reader.ValueSpan.ToArray();
}
else
{
decodedData = reader.GetBytesFromBase64();
}
break;
case "mimeType":
@ -230,17 +238,23 @@ public abstract class ContentBlock
Text = text ?? throw new JsonException("Text contents must be provided for 'text' type."),
},
"image" => new ImageContentBlock
{
Data = data ?? throw new JsonException("Image data must be provided for 'image' type."),
MimeType = mimeType ?? throw new JsonException("MIME type must be provided for 'image' type."),
},
"image" => decodedData is not null ?
ImageContentBlock.FromBytes(decodedData.Value,
mimeType ?? throw new JsonException("MIME type must be provided for 'image' type.")) :
new ImageContentBlock
{
Data = data ?? throw new JsonException("Image data must be provided for 'image' type."),
MimeType = mimeType ?? throw new JsonException("MIME type must be provided for 'image' type."),
},
"audio" => new AudioContentBlock
{
Data = data ?? throw new JsonException("Audio data must be provided for 'audio' type."),
MimeType = mimeType ?? throw new JsonException("MIME type must be provided for 'audio' type."),
},
"audio" => decodedData is not null ?
AudioContentBlock.FromBytes(decodedData.Value,
mimeType ?? throw new JsonException("MIME type must be provided for 'audio' type.")) :
new AudioContentBlock
{
Data = data ?? throw new JsonException("Audio data must be provided for 'audio' type."),
MimeType = mimeType ?? throw new JsonException("MIME type must be provided for 'audio' type."),
},
"resource" => new EmbeddedResourceBlock
{
@ -414,7 +428,7 @@ public sealed class TextContentBlock : ContentBlock
public sealed class ImageContentBlock : ContentBlock
{
private ReadOnlyMemory<byte>? _decodedData;
private ReadOnlyMemory<byte> _data;
private ReadOnlyMemory<byte>? _data;
/// <summary>
/// Creates an <see cref="ImageContentBlock"/> from decoded image bytes.
@ -423,7 +437,7 @@ public sealed class ImageContentBlock : ContentBlock
/// <param name="mimeType">The MIME type of the image.</param>
/// <returns>A new <see cref="ImageContentBlock"/> instance.</returns>
/// <remarks>
/// This method stores the provided bytes as <see cref="DecodedData"/> and encodes them to base64 UTF-8 bytes for <see cref="Data"/>.
/// This method stores the provided bytes as <see cref="DecodedData"/> and lazily encodes them to base64 UTF-8 bytes for <see cref="Data"/>.
/// </remarks>
/// <exception cref="ArgumentNullException"><paramref name="mimeType"/> is <see langword="null"/>.</exception>
/// <exception cref="ArgumentException"><paramref name="mimeType"/> is empty or composed entirely of whitespace.</exception>
@ -431,14 +445,19 @@ public sealed class ImageContentBlock : ContentBlock
{
Throw.IfNullOrWhiteSpace(mimeType);
ReadOnlyMemory<byte> data = EncodingUtilities.EncodeToBase64Utf8(bytes);
return new()
{
_decodedData = bytes,
Data = data,
MimeType = mimeType
};
return new(bytes, mimeType);
}
/// <summary>Initializes a new instance of the <see cref="ImageContentBlock"/> class.</summary>
public ImageContentBlock()
{
}
[SetsRequiredMembers]
private ImageContentBlock(ReadOnlyMemory<byte> decodedData, string mimeType)
{
_decodedData = decodedData;
MimeType = mimeType;
}
/// <inheritdoc/>
@ -453,7 +472,16 @@ public sealed class ImageContentBlock : ContentBlock
[JsonPropertyName("data")]
public required ReadOnlyMemory<byte> Data
{
get => _data;
get
{
if (_data is null)
{
Debug.Assert(_decodedData is not null);
_data = EncodingUtilities.EncodeToBase64Utf8(_decodedData!.Value);
}
return _data.Value;
}
set
{
_data = value;
@ -494,7 +522,14 @@ public sealed class ImageContentBlock : ContentBlock
public required string MimeType { get; set; }
[DebuggerBrowsable(DebuggerBrowsableState.Never)]
private string DebuggerDisplay => $"MimeType = {MimeType}, Length = {DebuggerDisplayHelper.GetBase64LengthDisplay(Data)}";
private string DebuggerDisplay
{
get
{
string lengthDisplay = _decodedData is not null ? $"{_decodedData.Value.Length} bytes" : DebuggerDisplayHelper.GetBase64LengthDisplay(Data);
return $"MimeType = {MimeType}, Length = {lengthDisplay}";
}
}
}
/// <summary>Represents audio provided to or from an LLM.</summary>
@ -502,7 +537,7 @@ public sealed class ImageContentBlock : ContentBlock
public sealed class AudioContentBlock : ContentBlock
{
private ReadOnlyMemory<byte>? _decodedData;
private ReadOnlyMemory<byte> _data;
private ReadOnlyMemory<byte>? _data;
/// <summary>
/// Creates an <see cref="AudioContentBlock"/> from decoded audio bytes.
@ -511,7 +546,7 @@ public sealed class AudioContentBlock : ContentBlock
/// <param name="mimeType">The MIME type of the audio.</param>
/// <returns>A new <see cref="AudioContentBlock"/> instance.</returns>
/// <remarks>
/// This method stores the provided bytes as <see cref="DecodedData"/> and encodes them to base64 UTF-8 bytes for <see cref="Data"/>.
/// This method stores the provided bytes as <see cref="DecodedData"/> and lazily encodes them to base64 UTF-8 bytes for <see cref="Data"/>.
/// </remarks>
/// <exception cref="ArgumentNullException"><paramref name="mimeType"/> is <see langword="null"/>.</exception>
/// <exception cref="ArgumentException"><paramref name="mimeType"/> is empty or composed entirely of whitespace.</exception>
@ -519,14 +554,19 @@ public sealed class AudioContentBlock : ContentBlock
{
Throw.IfNullOrWhiteSpace(mimeType);
ReadOnlyMemory<byte> data = EncodingUtilities.EncodeToBase64Utf8(bytes);
return new()
{
_decodedData = bytes,
Data = data,
MimeType = mimeType
};
return new(bytes, mimeType);
}
/// <summary>Initializes a new instance of the <see cref="AudioContentBlock"/> class.</summary>
public AudioContentBlock()
{
}
[SetsRequiredMembers]
private AudioContentBlock(ReadOnlyMemory<byte> decodedData, string mimeType)
{
_decodedData = decodedData;
MimeType = mimeType;
}
/// <inheritdoc/>
@ -541,7 +581,16 @@ public sealed class AudioContentBlock : ContentBlock
[JsonPropertyName("data")]
public required ReadOnlyMemory<byte> Data
{
get => _data;
get
{
if (_data is null)
{
Debug.Assert(_decodedData is not null);
_data = EncodingUtilities.EncodeToBase64Utf8(_decodedData!.Value);
}
return _data.Value;
}
set
{
_data = value;
@ -582,7 +631,14 @@ public sealed class AudioContentBlock : ContentBlock
public required string MimeType { get; set; }
[DebuggerBrowsable(DebuggerBrowsableState.Never)]
private string DebuggerDisplay => $"MimeType = {MimeType}, Length = {DebuggerDisplayHelper.GetBase64LengthDisplay(Data)}";
private string DebuggerDisplay
{
get
{
string lengthDisplay = _decodedData is not null ? $"{_decodedData.Value.Length} bytes" : DebuggerDisplayHelper.GetBase64LengthDisplay(Data);
return $"MimeType = {MimeType}, Length = {lengthDisplay}";
}
}
}
/// <summary>Represents the contents of a resource, embedded into a prompt or tool call result.</summary>

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@ -80,6 +80,7 @@ public abstract class ResourceContents
string? uri = null;
string? mimeType = null;
ReadOnlyMemory<byte>? blob = null;
ReadOnlyMemory<byte>? decodedBlob = null;
string? text = null;
JsonObject? meta = null;
@ -105,7 +106,14 @@ public abstract class ResourceContents
break;
case "blob":
blob = reader.HasValueSequence ? reader.ValueSequence.ToArray() : reader.ValueSpan.ToArray();
if (!reader.ValueIsEscaped)
{
blob = reader.HasValueSequence ? reader.ValueSequence.ToArray() : reader.ValueSpan.ToArray();
}
else
{
decodedBlob = reader.GetBytesFromBase64();
}
break;
case "text":
@ -122,6 +130,13 @@ public abstract class ResourceContents
}
}
if (decodedBlob is not null)
{
var blobResource = BlobResourceContents.FromBytes(decodedBlob.Value, uri ?? string.Empty, mimeType);
blobResource.Meta = meta;
return blobResource;
}
if (blob is not null)
{
return new BlobResourceContents

View file

@ -1,5 +1,6 @@
using Microsoft.Extensions.AI;
using ModelContextProtocol.Protocol;
using ModelContextProtocol.Tests.Protocol;
using System.Text.Json;
using System.Text.Json.Serialization;
@ -402,6 +403,183 @@ public class AIContentExtensionsTests
Assert.Null(exception);
}
[Theory]
[MemberData(nameof(ContentBlockTests.Base64TestData), MemberType = typeof(ContentBlockTests))]
public void ImageContentBlock_ToAIContent_RoundTrips(byte[] originalBytes)
{
var image = ImageContentBlock.FromBytes(originalBytes, "image/png");
var aiContent = Assert.IsType<DataContent>(image.ToAIContent());
Assert.Equal("image/png", aiContent.MediaType);
Assert.Equal(originalBytes, aiContent.Data.ToArray());
var roundTripped = Assert.IsType<ImageContentBlock>(aiContent.ToContentBlock());
Assert.Equal("image/png", roundTripped.MimeType);
Assert.Equal(originalBytes, roundTripped.DecodedData.ToArray());
}
[Theory]
[MemberData(nameof(ContentBlockTests.Base64TestData), MemberType = typeof(ContentBlockTests))]
public void ImageContentBlock_DataSetter_ToAIContent_RoundTrips(byte[] originalBytes)
{
string base64 = Convert.ToBase64String(originalBytes);
var image = new ImageContentBlock
{
Data = System.Text.Encoding.UTF8.GetBytes(base64),
MimeType = "image/jpeg"
};
var aiContent = Assert.IsType<DataContent>(image.ToAIContent());
Assert.Equal("image/jpeg", aiContent.MediaType);
Assert.Equal(originalBytes, aiContent.Data.ToArray());
var roundTripped = Assert.IsType<ImageContentBlock>(aiContent.ToContentBlock());
Assert.Equal("image/jpeg", roundTripped.MimeType);
Assert.Equal(originalBytes, roundTripped.DecodedData.ToArray());
}
[Theory]
[MemberData(nameof(ContentBlockTests.Base64TestData), MemberType = typeof(ContentBlockTests))]
public void AudioContentBlock_ToAIContent_RoundTrips(byte[] originalBytes)
{
var audio = AudioContentBlock.FromBytes(originalBytes, "audio/wav");
var aiContent = Assert.IsType<DataContent>(audio.ToAIContent());
Assert.Equal("audio/wav", aiContent.MediaType);
Assert.Equal(originalBytes, aiContent.Data.ToArray());
var roundTripped = Assert.IsType<AudioContentBlock>(aiContent.ToContentBlock());
Assert.Equal("audio/wav", roundTripped.MimeType);
Assert.Equal(originalBytes, roundTripped.DecodedData.ToArray());
}
[Theory]
[MemberData(nameof(ContentBlockTests.Base64TestData), MemberType = typeof(ContentBlockTests))]
public void AudioContentBlock_DataSetter_ToAIContent_RoundTrips(byte[] originalBytes)
{
string base64 = Convert.ToBase64String(originalBytes);
var audio = new AudioContentBlock
{
Data = System.Text.Encoding.UTF8.GetBytes(base64),
MimeType = "audio/mp3"
};
var aiContent = Assert.IsType<DataContent>(audio.ToAIContent());
Assert.Equal("audio/mp3", aiContent.MediaType);
Assert.Equal(originalBytes, aiContent.Data.ToArray());
var roundTripped = Assert.IsType<AudioContentBlock>(aiContent.ToContentBlock());
Assert.Equal("audio/mp3", roundTripped.MimeType);
Assert.Equal(originalBytes, roundTripped.DecodedData.ToArray());
}
[Theory]
[MemberData(nameof(ContentBlockTests.Base64TestData), MemberType = typeof(ContentBlockTests))]
public void BlobResourceContents_ToAIContent_RoundTrips(byte[] originalBytes)
{
var blob = BlobResourceContents.FromBytes(originalBytes, "file:///test.bin", "application/octet-stream");
var embedded = new EmbeddedResourceBlock { Resource = blob };
var aiContent = Assert.IsType<DataContent>(embedded.ToAIContent());
Assert.Equal("application/octet-stream", aiContent.MediaType);
Assert.Equal(originalBytes, aiContent.Data.ToArray());
var roundTripped = Assert.IsType<EmbeddedResourceBlock>(aiContent.ToContentBlock());
var roundTrippedBlob = Assert.IsType<BlobResourceContents>(roundTripped.Resource);
Assert.Equal("application/octet-stream", roundTrippedBlob.MimeType);
Assert.Equal(originalBytes, roundTrippedBlob.DecodedData.ToArray());
}
[Theory]
[MemberData(nameof(ContentBlockTests.Base64TestData), MemberType = typeof(ContentBlockTests))]
public void BlobResourceContents_BlobSetter_ToAIContent_RoundTrips(byte[] originalBytes)
{
string base64 = Convert.ToBase64String(originalBytes);
var blob = new BlobResourceContents
{
Blob = System.Text.Encoding.UTF8.GetBytes(base64),
Uri = "file:///test.bin",
MimeType = "application/octet-stream"
};
var embedded = new EmbeddedResourceBlock { Resource = blob };
var aiContent = Assert.IsType<DataContent>(embedded.ToAIContent());
Assert.Equal("application/octet-stream", aiContent.MediaType);
Assert.Equal(originalBytes, aiContent.Data.ToArray());
var roundTripped = Assert.IsType<EmbeddedResourceBlock>(aiContent.ToContentBlock());
var roundTrippedBlob = Assert.IsType<BlobResourceContents>(roundTripped.Resource);
Assert.Equal("application/octet-stream", roundTrippedBlob.MimeType);
Assert.Equal(originalBytes, roundTrippedBlob.DecodedData.ToArray());
}
[Theory]
[MemberData(nameof(ContentBlockTests.Base64TestData), MemberType = typeof(ContentBlockTests))]
public void ImageContentBlock_JsonDeserialized_ToAIContent_RoundTrips(byte[] originalBytes)
{
string base64 = Convert.ToBase64String(originalBytes);
string json = $$"""{"type":"image","data":"{{base64}}","mimeType":"image/png"}""";
var image = Assert.IsType<ImageContentBlock>(
JsonSerializer.Deserialize<ContentBlock>(json, McpJsonUtilities.DefaultOptions));
var aiContent = Assert.IsType<DataContent>(image.ToAIContent());
Assert.Equal(originalBytes, aiContent.Data.ToArray());
var roundTripped = Assert.IsType<ImageContentBlock>(aiContent.ToContentBlock());
Assert.Equal(originalBytes, roundTripped.DecodedData.ToArray());
}
[Theory]
[MemberData(nameof(ContentBlockTests.Base64TestData), MemberType = typeof(ContentBlockTests))]
public void ImageContentBlock_EscapedJsonDeserialized_ToAIContent_RoundTrips(byte[] originalBytes)
{
string base64 = Convert.ToBase64String(originalBytes);
string json = $$"""{"type":"image","data":"{{base64.Replace("/", "\\/")}}","mimeType":"image/png"}""";
var image = Assert.IsType<ImageContentBlock>(
JsonSerializer.Deserialize<ContentBlock>(json, McpJsonUtilities.DefaultOptions));
var aiContent = Assert.IsType<DataContent>(image.ToAIContent());
Assert.Equal(originalBytes, aiContent.Data.ToArray());
var roundTripped = Assert.IsType<ImageContentBlock>(aiContent.ToContentBlock());
Assert.Equal(originalBytes, roundTripped.DecodedData.ToArray());
}
[Theory]
[MemberData(nameof(ContentBlockTests.Base64TestData), MemberType = typeof(ContentBlockTests))]
public void AudioContentBlock_EscapedJsonDeserialized_ToAIContent_RoundTrips(byte[] originalBytes)
{
string base64 = Convert.ToBase64String(originalBytes);
string json = $$"""{"type":"audio","data":"{{base64.Replace("/", "\\/")}}","mimeType":"audio/wav"}""";
var audio = Assert.IsType<AudioContentBlock>(
JsonSerializer.Deserialize<ContentBlock>(json, McpJsonUtilities.DefaultOptions));
var aiContent = Assert.IsType<DataContent>(audio.ToAIContent());
Assert.Equal(originalBytes, aiContent.Data.ToArray());
var roundTripped = Assert.IsType<AudioContentBlock>(aiContent.ToContentBlock());
Assert.Equal(originalBytes, roundTripped.DecodedData.ToArray());
}
[Theory]
[MemberData(nameof(ContentBlockTests.Base64TestData), MemberType = typeof(ContentBlockTests))]
public void BlobResourceContents_EscapedJsonDeserialized_ToAIContent_RoundTrips(byte[] originalBytes)
{
string base64 = Convert.ToBase64String(originalBytes);
string json = $$"""{"uri":"file:///test.bin","blob":"{{base64.Replace("/", "\\/")}}","mimeType":"application/octet-stream"}""";
var blob = Assert.IsType<BlobResourceContents>(
JsonSerializer.Deserialize<ResourceContents>(json, McpJsonUtilities.DefaultOptions));
var embedded = new EmbeddedResourceBlock { Resource = blob };
var aiContent = Assert.IsType<DataContent>(embedded.ToAIContent());
Assert.Equal(originalBytes, aiContent.Data.ToArray());
var roundTripped = Assert.IsType<EmbeddedResourceBlock>(aiContent.ToContentBlock());
var roundTrippedBlob = Assert.IsType<BlobResourceContents>(roundTripped.Resource);
Assert.Equal(originalBytes, roundTrippedBlob.DecodedData.ToArray());
}
}
// Test type for named user-defined type test

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@ -1,4 +1,5 @@
using ModelContextProtocol.Protocol;
using System.Text;
using System.Text.Json;
namespace ModelContextProtocol.Tests.Protocol;
@ -290,4 +291,275 @@ public class ContentBlockTests
{
Assert.ThrowsAny<ArgumentException>(() => AudioContentBlock.FromBytes((byte[])[1, 2, 3], mimeType!));
}
[Fact]
public void ImageContentBlock_Deserialization_HandlesEscapedForwardSlashInBase64()
{
// Base64 uses '/' which some JSON encoders escape as '\/' (valid JSON).
// The converter must unescape before storing the base64 UTF-8 bytes.
byte[] originalBytes = [0xFF, 0xD8, 0xFF, 0xE0]; // sample bytes that produce '/' in base64
string base64 = Convert.ToBase64String(originalBytes); // "/9j/4A=="
Assert.Contains("/", base64);
// Simulate a JSON encoder that escapes '/' as '\/'
string json = $$"""{"type":"image","data":"{{base64.Replace("/", "\\/")}}","mimeType":"image/jpeg"}""";
var deserialized = JsonSerializer.Deserialize<ContentBlock>(json, McpJsonUtilities.DefaultOptions);
var image = Assert.IsType<ImageContentBlock>(deserialized);
Assert.Equal(base64, System.Text.Encoding.UTF8.GetString(image.Data.ToArray()));
Assert.Equal(originalBytes, image.DecodedData.ToArray());
}
[Fact]
public void AudioContentBlock_Deserialization_HandlesEscapedForwardSlashInBase64()
{
byte[] originalBytes = [0xFF, 0xD8, 0xFF, 0xE0];
string base64 = Convert.ToBase64String(originalBytes);
Assert.Contains("/", base64);
string json = $$"""{"type":"audio","data":"{{base64.Replace("/", "\\/")}}","mimeType":"audio/wav"}""";
var deserialized = JsonSerializer.Deserialize<ContentBlock>(json, McpJsonUtilities.DefaultOptions);
var audio = Assert.IsType<AudioContentBlock>(deserialized);
Assert.Equal(base64, System.Text.Encoding.UTF8.GetString(audio.Data.ToArray()));
Assert.Equal(originalBytes, audio.DecodedData.ToArray());
}
/// <summary>
/// Provides test data for base64 roundtrip tests. Each entry is a byte array that exercises
/// different base64 encoding characteristics:
/// - Various lengths producing 0, 1, or 2 padding characters
/// - Bytes that produce all 64 base64 alphabet characters including '+' and '/'
/// </summary>
public static TheoryData<byte[]> Base64TestData()
{
var data = new TheoryData<byte[]>
{
Array.Empty<byte>(), // empty: ""
new byte[] { 0x00 }, // 1 byte, 2 padding chars: "AA=="
new byte[] { 0x00, 0x01 }, // 2 bytes, 1 padding char: "AAE="
new byte[] { 0x00, 0x01, 0x02 }, // 3 bytes, no padding: "AAEC"
new byte[] { 0xFF, 0xD8, 0xFF, 0xE0 }, // produces '/' in base64: "/9j/4A=="
new byte[] { 0xFB, 0xEF, 0xBE }, // produces '+' in base64: "++++"
};
// All 256 byte values to exercise the full base64 alphabet
byte[] allBytes = new byte[256];
for (int i = 0; i < 256; i++)
{
allBytes[i] = (byte)i;
}
data.Add(allBytes);
// Larger payload (1024 bytes)
byte[] largePayload = new byte[1024];
new Random(42).NextBytes(largePayload);
data.Add(largePayload);
return data;
}
[Theory]
[MemberData(nameof(Base64TestData))]
public void ImageContentBlock_FromBytes_RoundtripsCorrectly(byte[] originalBytes)
{
string expectedBase64 = Convert.ToBase64String(originalBytes);
var image = ImageContentBlock.FromBytes(originalBytes, "image/png");
Assert.Equal("image/png", image.MimeType);
Assert.Equal(originalBytes, image.DecodedData.ToArray());
Assert.Equal(expectedBase64, Encoding.UTF8.GetString(image.Data.ToArray()));
}
[Theory]
[MemberData(nameof(Base64TestData))]
public void ImageContentBlock_DataSetter_RoundtripsCorrectly(byte[] originalBytes)
{
string base64 = Convert.ToBase64String(originalBytes);
byte[] base64Utf8 = Encoding.UTF8.GetBytes(base64);
var image = new ImageContentBlock { Data = base64Utf8, MimeType = "image/png" };
Assert.Equal(base64Utf8, image.Data.ToArray());
Assert.Equal(originalBytes, image.DecodedData.ToArray());
}
[Theory]
[MemberData(nameof(Base64TestData))]
public void ImageContentBlock_JsonRoundtrip_PreservesData(byte[] originalBytes)
{
string base64 = Convert.ToBase64String(originalBytes);
byte[] base64Utf8 = Encoding.UTF8.GetBytes(base64);
var original = new ImageContentBlock { Data = base64Utf8, MimeType = "image/png" };
string json = JsonSerializer.Serialize<ContentBlock>(original, McpJsonUtilities.DefaultOptions);
var deserialized = Assert.IsType<ImageContentBlock>(
JsonSerializer.Deserialize<ContentBlock>(json, McpJsonUtilities.DefaultOptions));
Assert.Equal(base64Utf8, deserialized.Data.ToArray());
Assert.Equal(originalBytes, deserialized.DecodedData.ToArray());
}
[Theory]
[MemberData(nameof(Base64TestData))]
public void ImageContentBlock_FromBytes_JsonRoundtrip_PreservesData(byte[] originalBytes)
{
string expectedBase64 = Convert.ToBase64String(originalBytes);
var original = ImageContentBlock.FromBytes(originalBytes, "image/jpeg");
string json = JsonSerializer.Serialize<ContentBlock>(original, McpJsonUtilities.DefaultOptions);
var deserialized = Assert.IsType<ImageContentBlock>(
JsonSerializer.Deserialize<ContentBlock>(json, McpJsonUtilities.DefaultOptions));
Assert.Equal(expectedBase64, Encoding.UTF8.GetString(deserialized.Data.ToArray()));
Assert.Equal(originalBytes, deserialized.DecodedData.ToArray());
}
[Theory]
[MemberData(nameof(Base64TestData))]
public void ImageContentBlock_EscapedJsonRoundtrip_PreservesData(byte[] originalBytes)
{
string base64 = Convert.ToBase64String(originalBytes);
// Simulate JSON encoder that escapes '/' as '\/'
string json = $$"""{"type":"image","data":"{{base64.Replace("/", "\\/")}}","mimeType":"image/png"}""";
var deserialized = Assert.IsType<ImageContentBlock>(
JsonSerializer.Deserialize<ContentBlock>(json, McpJsonUtilities.DefaultOptions));
Assert.Equal(base64, Encoding.UTF8.GetString(deserialized.Data.ToArray()));
Assert.Equal(originalBytes, deserialized.DecodedData.ToArray());
}
[Fact]
public void ImageContentBlock_DataSetterInvalidatesCachedDecodedData()
{
byte[] bytes1 = [1, 2, 3];
var image = ImageContentBlock.FromBytes(bytes1, "image/png");
// Access DecodedData to populate cache
Assert.Equal(bytes1, image.DecodedData.ToArray());
// Set new Data to invalidate cache
byte[] newBytes = [4, 5, 6];
string newBase64 = Convert.ToBase64String(newBytes);
image.Data = Encoding.UTF8.GetBytes(newBase64);
Assert.Equal(newBytes, image.DecodedData.ToArray());
}
[Theory]
[MemberData(nameof(Base64TestData))]
public void AudioContentBlock_FromBytes_RoundtripsCorrectly(byte[] originalBytes)
{
string expectedBase64 = Convert.ToBase64String(originalBytes);
var audio = AudioContentBlock.FromBytes(originalBytes, "audio/wav");
Assert.Equal("audio/wav", audio.MimeType);
Assert.Equal(originalBytes, audio.DecodedData.ToArray());
Assert.Equal(expectedBase64, Encoding.UTF8.GetString(audio.Data.ToArray()));
}
[Theory]
[MemberData(nameof(Base64TestData))]
public void AudioContentBlock_DataSetter_RoundtripsCorrectly(byte[] originalBytes)
{
string base64 = Convert.ToBase64String(originalBytes);
byte[] base64Utf8 = Encoding.UTF8.GetBytes(base64);
var audio = new AudioContentBlock { Data = base64Utf8, MimeType = "audio/wav" };
Assert.Equal(base64Utf8, audio.Data.ToArray());
Assert.Equal(originalBytes, audio.DecodedData.ToArray());
}
[Theory]
[MemberData(nameof(Base64TestData))]
public void AudioContentBlock_JsonRoundtrip_PreservesData(byte[] originalBytes)
{
string base64 = Convert.ToBase64String(originalBytes);
byte[] base64Utf8 = Encoding.UTF8.GetBytes(base64);
var original = new AudioContentBlock { Data = base64Utf8, MimeType = "audio/wav" };
string json = JsonSerializer.Serialize<ContentBlock>(original, McpJsonUtilities.DefaultOptions);
var deserialized = Assert.IsType<AudioContentBlock>(
JsonSerializer.Deserialize<ContentBlock>(json, McpJsonUtilities.DefaultOptions));
Assert.Equal(base64Utf8, deserialized.Data.ToArray());
Assert.Equal(originalBytes, deserialized.DecodedData.ToArray());
}
[Theory]
[MemberData(nameof(Base64TestData))]
public void AudioContentBlock_FromBytes_JsonRoundtrip_PreservesData(byte[] originalBytes)
{
string expectedBase64 = Convert.ToBase64String(originalBytes);
var original = AudioContentBlock.FromBytes(originalBytes, "audio/mp3");
string json = JsonSerializer.Serialize<ContentBlock>(original, McpJsonUtilities.DefaultOptions);
var deserialized = Assert.IsType<AudioContentBlock>(
JsonSerializer.Deserialize<ContentBlock>(json, McpJsonUtilities.DefaultOptions));
Assert.Equal(expectedBase64, Encoding.UTF8.GetString(deserialized.Data.ToArray()));
Assert.Equal(originalBytes, deserialized.DecodedData.ToArray());
}
[Theory]
[MemberData(nameof(Base64TestData))]
public void AudioContentBlock_EscapedJsonRoundtrip_PreservesData(byte[] originalBytes)
{
string base64 = Convert.ToBase64String(originalBytes);
string json = $$"""{"type":"audio","data":"{{base64.Replace("/", "\\/")}}","mimeType":"audio/wav"}""";
var deserialized = Assert.IsType<AudioContentBlock>(
JsonSerializer.Deserialize<ContentBlock>(json, McpJsonUtilities.DefaultOptions));
Assert.Equal(base64, Encoding.UTF8.GetString(deserialized.Data.ToArray()));
Assert.Equal(originalBytes, deserialized.DecodedData.ToArray());
}
[Fact]
public void AudioContentBlock_DataSetterInvalidatesCachedDecodedData()
{
byte[] bytes1 = [1, 2, 3];
var audio = AudioContentBlock.FromBytes(bytes1, "audio/wav");
Assert.Equal(bytes1, audio.DecodedData.ToArray());
byte[] newBytes = [4, 5, 6];
string newBase64 = Convert.ToBase64String(newBytes);
audio.Data = Encoding.UTF8.GetBytes(newBase64);
Assert.Equal(newBytes, audio.DecodedData.ToArray());
}
[Theory]
[MemberData(nameof(Base64TestData))]
public void ImageContentBlock_FromBytes_LazilyEncodesData(byte[] originalBytes)
{
// FromBytes should only decode when Data is accessed
var image = ImageContentBlock.FromBytes(originalBytes, "image/png");
// First, access DecodedData without touching Data
Assert.Equal(originalBytes, image.DecodedData.ToArray());
// Now access Data and verify it lazily encoded correctly
string expectedBase64 = Convert.ToBase64String(originalBytes);
Assert.Equal(expectedBase64, Encoding.UTF8.GetString(image.Data.ToArray()));
}
[Theory]
[MemberData(nameof(Base64TestData))]
public void AudioContentBlock_FromBytes_LazilyEncodesData(byte[] originalBytes)
{
var audio = AudioContentBlock.FromBytes(originalBytes, "audio/wav");
Assert.Equal(originalBytes, audio.DecodedData.ToArray());
string expectedBase64 = Convert.ToBase64String(originalBytes);
Assert.Equal(expectedBase64, Encoding.UTF8.GetString(audio.Data.ToArray()));
}
}

View file

@ -1,4 +1,5 @@
using ModelContextProtocol.Protocol;
using System.Text;
using System.Text.Json;
namespace ModelContextProtocol.Tests.Protocol;
@ -489,4 +490,129 @@ public static class ResourceContentsTests
Assert.DoesNotContain("mimeType", json);
}
[Fact]
public static void BlobResourceContents_Deserialization_HandlesEscapedForwardSlashInBase64()
{
// Base64 uses '/' which some JSON encoders escape as '\/' (valid JSON).
// The converter must unescape before storing the base64 UTF-8 bytes.
byte[] originalBytes = [0xFF, 0xD8, 0xFF, 0xE0]; // sample bytes that produce '/' in base64
string base64 = Convert.ToBase64String(originalBytes); // "/9j/4A=="
Assert.Contains("/", base64);
// Simulate a JSON encoder that escapes '/' as '\/'
string json = $$"""{"uri":"file:///test.bin","blob":"{{base64.Replace("/", "\\/")}}","mimeType":"application/octet-stream"}""";
var deserialized = JsonSerializer.Deserialize<ResourceContents>(json, McpJsonUtilities.DefaultOptions);
var blob = Assert.IsType<BlobResourceContents>(deserialized);
Assert.Equal(base64, System.Text.Encoding.UTF8.GetString(blob.Blob.ToArray()));
Assert.Equal(originalBytes, blob.DecodedData.ToArray());
}
[Theory]
[MemberData(nameof(ContentBlockTests.Base64TestData), MemberType = typeof(ContentBlockTests))]
public static void BlobResourceContents_FromBytes_RoundtripsCorrectly(byte[] originalBytes)
{
string expectedBase64 = Convert.ToBase64String(originalBytes);
var blob = BlobResourceContents.FromBytes(originalBytes, "file:///test.bin", "application/octet-stream");
Assert.Equal("file:///test.bin", blob.Uri);
Assert.Equal("application/octet-stream", blob.MimeType);
Assert.Equal(originalBytes, blob.DecodedData.ToArray());
Assert.Equal(expectedBase64, Encoding.UTF8.GetString(blob.Blob.ToArray()));
}
[Theory]
[MemberData(nameof(ContentBlockTests.Base64TestData), MemberType = typeof(ContentBlockTests))]
public static void BlobResourceContents_BlobSetter_RoundtripsCorrectly(byte[] originalBytes)
{
string base64 = Convert.ToBase64String(originalBytes);
byte[] base64Utf8 = Encoding.UTF8.GetBytes(base64);
var blob = new BlobResourceContents { Blob = base64Utf8, Uri = "file:///test.bin" };
Assert.Equal(base64Utf8, blob.Blob.ToArray());
Assert.Equal(originalBytes, blob.DecodedData.ToArray());
}
[Theory]
[MemberData(nameof(ContentBlockTests.Base64TestData), MemberType = typeof(ContentBlockTests))]
public static void BlobResourceContents_JsonRoundtrip_PreservesData(byte[] originalBytes)
{
string base64 = Convert.ToBase64String(originalBytes);
byte[] base64Utf8 = Encoding.UTF8.GetBytes(base64);
var original = new BlobResourceContents
{
Blob = base64Utf8,
Uri = "file:///test.bin",
MimeType = "application/octet-stream"
};
string json = JsonSerializer.Serialize<ResourceContents>(original, McpJsonUtilities.DefaultOptions);
var deserialized = Assert.IsType<BlobResourceContents>(
JsonSerializer.Deserialize<ResourceContents>(json, McpJsonUtilities.DefaultOptions));
Assert.Equal(base64Utf8, deserialized.Blob.ToArray());
Assert.Equal(originalBytes, deserialized.DecodedData.ToArray());
}
[Theory]
[MemberData(nameof(ContentBlockTests.Base64TestData), MemberType = typeof(ContentBlockTests))]
public static void BlobResourceContents_FromBytes_JsonRoundtrip_PreservesData(byte[] originalBytes)
{
string expectedBase64 = Convert.ToBase64String(originalBytes);
var original = BlobResourceContents.FromBytes(originalBytes, "file:///test.bin", "application/octet-stream");
string json = JsonSerializer.Serialize<ResourceContents>(original, McpJsonUtilities.DefaultOptions);
var deserialized = Assert.IsType<BlobResourceContents>(
JsonSerializer.Deserialize<ResourceContents>(json, McpJsonUtilities.DefaultOptions));
Assert.Equal(expectedBase64, Encoding.UTF8.GetString(deserialized.Blob.ToArray()));
Assert.Equal(originalBytes, deserialized.DecodedData.ToArray());
}
[Theory]
[MemberData(nameof(ContentBlockTests.Base64TestData), MemberType = typeof(ContentBlockTests))]
public static void BlobResourceContents_EscapedJsonRoundtrip_PreservesData(byte[] originalBytes)
{
string base64 = Convert.ToBase64String(originalBytes);
string json = $$"""{"uri":"file:///test.bin","blob":"{{base64.Replace("/", "\\/")}}","mimeType":"application/octet-stream"}""";
var deserialized = Assert.IsType<BlobResourceContents>(
JsonSerializer.Deserialize<ResourceContents>(json, McpJsonUtilities.DefaultOptions));
Assert.Equal(base64, Encoding.UTF8.GetString(deserialized.Blob.ToArray()));
Assert.Equal(originalBytes, deserialized.DecodedData.ToArray());
}
[Fact]
public static void BlobResourceContents_BlobSetterInvalidatesCachedDecodedData()
{
byte[] bytes1 = [1, 2, 3];
var blob = BlobResourceContents.FromBytes(bytes1, "file:///test.bin");
Assert.Equal(bytes1, blob.DecodedData.ToArray());
byte[] newBytes = [4, 5, 6];
string newBase64 = Convert.ToBase64String(newBytes);
blob.Blob = Encoding.UTF8.GetBytes(newBase64);
Assert.Equal(newBytes, blob.DecodedData.ToArray());
}
[Theory]
[MemberData(nameof(ContentBlockTests.Base64TestData), MemberType = typeof(ContentBlockTests))]
public static void BlobResourceContents_FromBytes_LazilyEncodesBlob(byte[] originalBytes)
{
var blob = BlobResourceContents.FromBytes(originalBytes, "file:///test.bin");
// Access DecodedData first without touching Blob
Assert.Equal(originalBytes, blob.DecodedData.ToArray());
// Now access Blob and verify lazy encoding
string expectedBase64 = Convert.ToBase64String(originalBytes);
Assert.Equal(expectedBase64, Encoding.UTF8.GetString(blob.Blob.ToArray()));
}
}