[automated] Merge branch 'main' => 'dev'

.github/policies/resourceManagement.yml

@@ -214,8 +214,6 @@ configuration:
         - isAction:
             action: Closed
       then:
-      - removeLabel:
-          label: untriaged
       - removeLabel:
           label: 'work in progress :construction:'
       - removeLabel:

.github/policies/untriaged.yml

@@ -0,0 +1,36 @@
+id: untriaged
+name: Automatically apply and remove the untriaged label
+resource: repository
+disabled: false
+where:
+configuration:
+  resourceManagementConfiguration:
+    eventResponderTasks:
+    - description: Add untriaged label to new/reopened issues without a milestone
+      if:
+      - payloadType: Issues
+      - or:
+        - isAction:
+            action: Opened
+        - isAction:
+            action: Reopened
+      - isOpen
+      - not: isPartOfAnyMilestone
+      - not:
+          hasLabel:
+            label: untriaged
+      then:
+      - addLabel:
+          label: untriaged
+
+    - description: Remove untriaged label from closed issues
+      if:
+      - payloadType: Issues
+      - hasLabel:
+          label: untriaged
+      - or:
+        - isAction:
+            action: Closed
+      then:
+      - removeLabel:
+          label: untriaged

src/Libraries/Microsoft.Extensions.AI.Abstractions/Contents/AIContent.cs

@@ -11,6 +11,7 @@ namespace Microsoft.Extensions.AI;
 [JsonDerivedType(typeof(FunctionCallContent), typeDiscriminator: "functionCall")]
 [JsonDerivedType(typeof(FunctionResultContent), typeDiscriminator: "functionResult")]
 [JsonDerivedType(typeof(TextContent), typeDiscriminator: "text")]
+[JsonDerivedType(typeof(UriContent), typeDiscriminator: "uri")]
 [JsonDerivedType(typeof(UsageContent), typeDiscriminator: "usage")]
 public class AIContent
 {

src/Libraries/Microsoft.Extensions.AI.Abstractions/Contents/DataContent.cs

@@ -8,17 +8,17 @@
 using Microsoft.Shared.Diagnostics;
 
 #pragma warning disable S3996 // URI properties should not be strings
+#pragma warning disable CA1054 // URI-like parameters should not be strings
 #pragma warning disable CA1056 // URI-like properties should not be strings
 
 namespace Microsoft.Extensions.AI;
 
 /// <summary>
-/// Represents data content, such as an image or audio.
+/// Represents binary content with an associated media type (also known as MIME type).
 /// </summary>
 /// <remarks>
 /// <para>
-/// The represented content may either be the actual bytes stored in this instance, or it may
-/// be a URI that references the location of the content.
+/// The content represents in-memory data. For references to data at a remote URI, use <see cref="UriContent"/> instead.
 /// </para>
 /// <para>
 /// <see cref="Uri"/> always returns a valid URI string, even if the instance was constructed from
@@ -32,20 +32,27 @@ public class DataContent : AIContent
     // Ideally DataContent would be based in terms of Uri. However, Uri has a length limitation that makes it prohibitive
     // for the kinds of data URIs necessary to support here. As such, this type is based in strings.
 
+    /// <summary>Parsed data URI information.</summary>
+    private readonly DataUriParser.DataUri? _dataUri;
+
     /// <summary>The string-based representation of the URI, including any data in the instance.</summary>
     private string? _uri;
 
     /// <summary>The data, lazily initialized if the data is provided in a data URI.</summary>
     private ReadOnlyMemory<byte>? _data;
 
-    /// <summary>Parsed data URI information.</summary>
-    private DataUriParser.DataUri? _dataUri;
-
     /// <summary>
     /// Initializes a new instance of the <see cref="DataContent"/> class.
     /// </summary>
-    /// <param name="uri">The URI of the content. This can be a data URI.</param>
-    /// <param name="mediaType">The media type (also known as MIME type) represented by the content.</param>
+    /// <param name="uri">The data URI containing the content.</param>
+    /// <param name="mediaType">
+    /// The media type (also known as MIME type) represented by the content. If not provided,
+    /// it must be provided as part of the <paramref name="uri"/>.
+    /// </param>
+    /// <exception cref="ArgumentNullException"><paramref name="uri"/> is <see langword="null"/>.</exception>
+    /// <exception cref="ArgumentException"><paramref name="uri"/> is not a data URI.</exception>
+    /// <exception cref="ArgumentException"><paramref name="uri"/> did not contain a media type and <paramref name="mediaType"/> was not supplied.</exception>
+    /// <exception cref="ArgumentException"><paramref name="mediaType"/> is an invalid media type.</exception>
     public DataContent(Uri uri, string? mediaType = null)
         : this(Throw.IfNull(uri).ToString(), mediaType)
     {
@@ -54,75 +61,78 @@ public DataContent(Uri uri, string? mediaType = null)
     /// <summary>
     /// Initializes a new instance of the <see cref="DataContent"/> class.
     /// </summary>
-    /// <param name="uri">The URI of the content. This can be a data URI.</param>
+    /// <param name="uri">The data URI containing the content.</param>
     /// <param name="mediaType">The media type (also known as MIME type) represented by the content.</param>
+    /// <exception cref="ArgumentNullException"><paramref name="uri"/> is <see langword="null"/>.</exception>
+    /// <exception cref="ArgumentException"><paramref name="uri"/> is not a data URI.</exception>
+    /// <exception cref="ArgumentException"><paramref name="uri"/> did not contain a media type and <paramref name="mediaType"/> was not supplied.</exception>
+    /// <exception cref="ArgumentException"><paramref name="mediaType"/> is an invalid media type.</exception>
     [JsonConstructor]
     public DataContent([StringSyntax(StringSyntaxAttribute.Uri)] string uri, string? mediaType = null)
     {
         _uri = Throw.IfNullOrWhitespace(uri);
 
-        ValidateMediaType(ref mediaType);
-        MediaType = mediaType;
-
-        if (uri.StartsWith(DataUriParser.Scheme, StringComparison.OrdinalIgnoreCase))
+        if (!uri.StartsWith(DataUriParser.Scheme, StringComparison.OrdinalIgnoreCase))
         {
-            _dataUri = DataUriParser.Parse(uri.AsMemory());
+            Throw.ArgumentException(nameof(uri), "The provided URI is not a data URI.");
+        }
 
-            // If the data URI contains a media type that's different from a non-null media type
-            // explicitly provided, prefer the one explicitly provided as an override.
-            if (MediaType is not null)
-            {
-                if (MediaType != _dataUri.MediaType)
-                {
-                    // Extract the bytes from the data URI and null out the uri.
-                    // Then we'll lazily recreate it later if needed based on the updated media type.
-                    _data = _dataUri.ToByteArray();
-                    _dataUri = null;
-                    _uri = null;
-                }
-            }
-            else
+        _dataUri = DataUriParser.Parse(uri.AsMemory());
+
+        if (mediaType is null)
+        {
+            mediaType = _dataUri.MediaType;
+            if (mediaType is null)
             {
-                MediaType = _dataUri.MediaType;
+                Throw.ArgumentNullException(nameof(mediaType), $"{nameof(uri)} did not contain a media type, and {nameof(mediaType)} was not provided.");
             }
         }
-        else if (!System.Uri.TryCreate(uri, UriKind.Absolute, out _))
+        else
         {
-            throw new UriFormatException("The URI is not well-formed.");
+            if (mediaType != _dataUri.MediaType)
+            {
+                // If the data URI contains a media type that's different from a non-null media type
+                // explicitly provided, prefer the one explicitly provided as an override.
+
+                // Extract the bytes from the data URI and null out the uri.
+                // Then we'll lazily recreate it later if needed based on the updated media type.
+                _data = _dataUri.ToByteArray();
+                _dataUri = null;
+                _uri = null;
+            }
         }
+
+        MediaType = DataUriParser.ThrowIfInvalidMediaType(mediaType);
     }
 
     /// <summary>
     /// Initializes a new instance of the <see cref="DataContent"/> class.
     /// </summary>
     /// <param name="data">The byte contents.</param>
     /// <param name="mediaType">The media type (also known as MIME type) represented by the content.</param>
-    public DataContent(ReadOnlyMemory<byte> data, string? mediaType = null)
+    /// <exception cref="ArgumentNullException"><paramref name="mediaType"/> is null.</exception>
+    /// <exception cref="ArgumentException"><paramref name="mediaType"/> is empty or composed entirely of whitespace.</exception>
+    public DataContent(ReadOnlyMemory<byte> data, string mediaType)
     {
-        ValidateMediaType(ref mediaType);
-        MediaType = mediaType;
+        MediaType = DataUriParser.ThrowIfInvalidMediaType(mediaType);
 
         _data = data;
     }
 
     /// <summary>
-    /// Determines whether the <see cref="MediaType"/> has the specified prefix.
+    /// Determines whether the <see cref="MediaType"/>'s top-level type matches the specified <paramref name="topLevelType"/>.
     /// </summary>
-    /// <param name="prefix">The media type prefix.</param>
-    /// <returns><see langword="true"/> if the <see cref="MediaType"/> has the specified prefix, otherwise <see langword="false"/>.</returns>
-    public bool MediaTypeStartsWith(string prefix)
-        => MediaType?.StartsWith(prefix, StringComparison.OrdinalIgnoreCase) is true;
-
-    /// <summary>Sets <paramref name="mediaType"/> to null if it's empty or composed entirely of whitespace.</summary>
-    private static void ValidateMediaType(ref string? mediaType)
-    {
-        if (!DataUriParser.IsValidMediaType(mediaType.AsSpan(), ref mediaType))
-        {
-            Throw.ArgumentException(nameof(mediaType), "Invalid media type.");
-        }
-    }
+    /// <param name="topLevelType">The type to compare against <see cref="MediaType"/>.</param>
+    /// <returns><see langword="true"/> if the type portion of <see cref="MediaType"/> matches the specified value; otherwise, false.</returns>
+    /// <remarks>
+    /// A media type is primarily composed of two parts, a "type" and a "subtype", separated by a slash ("/").
+    /// The type portion is also referred to as the "top-level type"; for example,
+    /// "image/png" has a top-level type of "image". <see cref="HasTopLevelMediaType"/> compares
+    /// the specified <paramref name="topLevelType"/> against the type portion of <see cref="MediaType"/>.
+    /// </remarks>
+    public bool HasTopLevelMediaType(string topLevelType) => DataUriParser.HasTopLevelMediaType(MediaType, topLevelType);
 
-    /// <summary>Gets the URI for this <see cref="DataContent"/>.</summary>
+    /// <summary>Gets the data URI for this <see cref="DataContent"/>.</summary>
     /// <remarks>
     /// The returned URI is always a valid URI string, even if the instance was constructed from a <see cref="ReadOnlyMemory{Byte}"/>
     /// or from a <see cref="System.Uri"/>. In the case of a <see cref="ReadOnlyMemory{T}"/>, this property returns a data URI containing
@@ -137,8 +147,8 @@ public string Uri
             {
                 if (_dataUri is null)
                 {
-                    Debug.Assert(Data is not null, "Expected Data to be initialized.");
-                    _uri = string.Concat("data:", MediaType, ";base64,", Convert.ToBase64String(Data.GetValueOrDefault()
+                    Debug.Assert(_data is not null, "Expected _data to be initialized.");
+                    _uri = string.Concat("data:", MediaType, ";base64,", Convert.ToBase64String(_data.GetValueOrDefault()
 #if NET
                         .Span));
 #else
@@ -167,10 +177,9 @@ public string Uri
     /// If the media type was explicitly specified, this property returns that value.
     /// If the media type was not explicitly specified, but a data URI was supplied and that data URI contained a non-default
     /// media type, that media type is returned.
-    /// Otherwise, this property returns null.
     /// </remarks>
-    [JsonPropertyOrder(1)]
-    public string? MediaType { get; private set; }
+    [JsonIgnore]
+    public string MediaType { get; }
 
     /// <summary>Gets the data represented by this instance.</summary>
     /// <remarks>
@@ -181,16 +190,18 @@ public string Uri
     /// no attempt is made to retrieve the data from that URI.
     /// </remarks>
     [JsonIgnore]
-    public ReadOnlyMemory<byte>? Data
+    public ReadOnlyMemory<byte> Data
     {
         get
         {
-            if (_dataUri is not null)
+            if (_data is null)
             {
-                _data ??= _dataUri.ToByteArray();
+                Debug.Assert(_dataUri is not null, "Expected dataUri to be initialized.");
+                _data = _dataUri!.ToByteArray();
             }
 
-            return _data;
+            Debug.Assert(_data is not null, "Expected data to be initialized.");
+            return _data.GetValueOrDefault();
         }
     }
 

src/Libraries/Microsoft.Extensions.AI.Abstractions/Contents/DataUriParser.cs

@@ -5,10 +5,14 @@
 #if NET8_0_OR_GREATER
 using System.Buffers.Text;
 #endif
-using System.Diagnostics;
+using System.Diagnostics.CodeAnalysis;
 using System.Net;
 using System.Net.Http.Headers;
+using System.Runtime.CompilerServices;
 using System.Text;
+using Microsoft.Shared.Diagnostics;
+
+#pragma warning disable CA1307 // Specify StringComparison for clarity
 
 namespace Microsoft.Extensions.AI;
 
@@ -55,29 +59,35 @@ public static DataUri Parse(ReadOnlyMemory<char> dataUri)
         }
 
         // Validate the media type, if present.
+        ReadOnlySpan<char> span = metadata.Span.Trim();
         string? mediaType = null;
-        if (!IsValidMediaType(metadata.Span.Trim(), ref mediaType))
+        if (!span.IsEmpty && !IsValidMediaType(span, ref mediaType))
         {
             throw new UriFormatException("Invalid data URI format: the media type is not a valid.");
         }
 
         return new DataUri(data, isBase64, mediaType);
     }
 
-    /// <summary>Validates that a media type is valid, and if successful, ensures we have it as a string.</summary>
-    public static bool IsValidMediaType(ReadOnlySpan<char> mediaTypeSpan, ref string? mediaType)
+    public static string ThrowIfInvalidMediaType(
+        string mediaType, [CallerArgumentExpression(nameof(mediaType))] string parameterName = "")
     {
-        Debug.Assert(
-            mediaType is null || mediaTypeSpan.Equals(mediaType.AsSpan(), StringComparison.Ordinal),
-            "mediaType string should either be null or the same as the span");
+        _ = Throw.IfNullOrWhitespace(mediaType, parameterName);
 
-        // If the media type is empty or all whitespace, normalize it to null.
-        if (mediaTypeSpan.IsWhiteSpace())
+        if (!IsValidMediaType(mediaType))
         {
-            mediaType = null;
-            return true;
+            Throw.ArgumentException(parameterName, $"An invalid media type was specified: '{mediaType}'");
         }
 
+        return mediaType;
+    }
+
+    public static bool IsValidMediaType(string mediaType) =>
+        IsValidMediaType(mediaType.AsSpan(), ref mediaType);
+
+    /// <summary>Validates that a media type is valid, and if successful, ensures we have it as a string.</summary>
+    public static bool IsValidMediaType(ReadOnlySpan<char> mediaTypeSpan, [NotNull] ref string? mediaType)
+    {
         // For common media types, we can avoid both allocating a string for the span and avoid parsing overheads.
         string? knownType = mediaTypeSpan switch
         {
@@ -108,7 +118,7 @@ public static bool IsValidMediaType(ReadOnlySpan<char> mediaTypeSpan, ref string
         };
         if (knownType is not null)
         {
-            mediaType ??= knownType;
+            mediaType = knownType;
             return true;
         }
 
@@ -117,6 +127,16 @@ public static bool IsValidMediaType(ReadOnlySpan<char> mediaTypeSpan, ref string
         return MediaTypeHeaderValue.TryParse(mediaType, out _);
     }
 
+    public static bool HasTopLevelMediaType(string mediaType, string topLevelMediaType)
+    {
+        int slashIndex = mediaType.IndexOf('/');
+
+        ReadOnlySpan<char> span = slashIndex < 0 ? mediaType.AsSpan() : mediaType.AsSpan(0, slashIndex);
+        span = span.Trim();
+
+        return span.Equals(topLevelMediaType.AsSpan(), StringComparison.OrdinalIgnoreCase);
+    }
+
     /// <summary>Test whether the value is a base64 string without whitespace.</summary>
     private static bool IsValidBase64Data(ReadOnlySpan<char> value)
     {