✨ Added support for sitemap images #7

src/Sidio.Sitemap.Core.Tests/Extensions/SitemapImageLocationTests.cs

@@ -0,0 +1,32 @@
+using Sidio.Sitemap.Core.Extensions;
+
+namespace Sidio.Sitemap.Core.Tests.Extensions;
+
+public sealed class SitemapImageLocationTests
+{
+    [Fact]
+    public void Construct_WithValidArguments_SitemapImageLocationConstructed()
+    {
+        // arrange
+        const string Url = "http://www.example.com";
+
+        // act
+        var sitemapNode = new SitemapImageLocation(Url);
+
+        // assert
+        sitemapNode.Url.Should().Be(Url);
+    }
+
+    [Theory]
+    [InlineData("")]
+    [InlineData(" ")]
+    [InlineData(null)]
+    public void Construct_WithEmptyUrl_ThrowException(string? url)
+    {
+        // act
+        var sitemapNodeAction = () => new SitemapImageLocation(url!);
+
+        // assert
+        sitemapNodeAction.Should().ThrowExactly<ArgumentNullException>();
+    }
+}

src/Sidio.Sitemap.Core.Tests/Extensions/SitemapImageNodeTests.cs

@@ -0,0 +1,73 @@
+using Sidio.Sitemap.Core.Extensions;
+
+namespace Sidio.Sitemap.Core.Tests.Extensions;
+
+public sealed class SitemapImageNodeTests
+{
+    private readonly Fixture _fixture = new ();
+
+    [Fact]
+    public void Construct_WithValidArguments_SitemapImageLocationConstructed()
+    {
+        // arrange
+        const string Url = "http://www.example.com";
+        var imageLocation = new SitemapImageLocation(Url);
+
+        // act
+        var sitemapNode = new SitemapImageNode(Url, imageLocation);
+
+        // assert
+        sitemapNode.Url.Should().Be(Url);
+        sitemapNode.Images.Should().HaveCount(1);
+        sitemapNode.Images.Should().Contain(imageLocation);
+    }
+
+    [Fact]
+    public void Construct_WithValidArguments_MultipleImages_SitemapImageLocationConstructed()
+    {
+        // arrange
+        const string Url = "http://www.example.com";
+        var imageLocations = _fixture.CreateMany<SitemapImageLocation>().ToList();
+
+        // act
+        var sitemapNode = new SitemapImageNode(Url, imageLocations);
+
+        // assert
+        sitemapNode.Url.Should().Be(Url);
+        sitemapNode.Images.Should().HaveCount(imageLocations.Count);
+        sitemapNode.Images.Should().Contain(imageLocations);
+    }
+
+    [Theory]
+    [InlineData("")]
+    [InlineData(" ")]
+    [InlineData(null)]
+    public void Construct_WithEmptyUrl_ThrowException(string? url)
+    {
+        // act
+        var sitemapNodeAction = () => new SitemapImageNode(url!, new SitemapImageLocation("http://www.example.com"));
+
+        // assert
+        sitemapNodeAction.Should().ThrowExactly<ArgumentNullException>();
+    }
+
+    [Fact]
+    public void Construct_WithoutImages_ThrowException()
+    {
+        // act
+        var sitemapNodeAction = () => new SitemapImageNode("http://www.example.com", []);
+
+        // assert
+        sitemapNodeAction.Should().ThrowExactly<ArgumentException>();
+    }
+
+    [Fact]
+    public void Construct_WithoutTooManyImages_ThrowException()
+    {
+        // act
+        var sitemapNodeAction = () => new SitemapImageNode("http://www.example.com", new List<SitemapImageLocation>(1001).ToArray());
+
+        // assert
+        sitemapNodeAction.Should().ThrowExactly<ArgumentException>();
+    }
+}

src/Sidio.Sitemap.Core.Tests/Serialization/XmlSerializerTests.cs

@@ -1,4 +1,5 @@
-using Sidio.Sitemap.Core.Serialization;
+using Sidio.Sitemap.Core.Extensions;
+using Sidio.Sitemap.Core.Serialization;
 
 namespace Sidio.Sitemap.Core.Tests.Serialization;
 
@@ -16,6 +17,7 @@ public void Serialize_WithSitemap_ReturnsXml()
         var changeFrequency = _fixture.Create<ChangeFrequency>();
         sitemap.Add(new SitemapNode(Url, now, changeFrequency, 0.32m));
         var serializer = new XmlSerializer();
+
         var expectedUrl = Url.Replace("&", "&amp;").Replace(">", "&gt;").Replace("<", "&lt;").Replace("'", "&apos;").Replace("\"", "&quot;");
 
         // act
@@ -27,6 +29,29 @@ public void Serialize_WithSitemap_ReturnsXml()
             $"<?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"no\"?><urlset xmlns=\"http://www.sitemaps.org/schemas/sitemap/0.9\"><url><loc>{expectedUrl}</loc><lastmod>{now:yyyy-MM-dd}</lastmod><changefreq>{changeFrequency.ToString().ToLower()}</changefreq><priority>0.3</priority></url></urlset>");
     }
 
+    [Fact]
+    public void Serialize_WithSitemapContainsImageNodes_ReturnsXml()
+    {
+        // arrange
+        const string Url = "https://example.com/?id=1&name=example&gt=>&lt=<&quotes=";
+        var sitemap = new Sitemap();
+        var now = DateTime.UtcNow;
+        var changeFrequency = _fixture.Create<ChangeFrequency>();
+        sitemap.Add(new SitemapNode(Url, now, changeFrequency, 0.32m));
+        sitemap.Add(new SitemapImageNode(Url, new SitemapImageLocation(Url)));
+        var serializer = new XmlSerializer();
+
+        var expectedUrl = Url.Replace("&", "&amp;").Replace(">", "&gt;").Replace("<", "&lt;").Replace("'", "&apos;").Replace("\"", "&quot;");
+
+        // act
+        var result = serializer.Serialize(sitemap);
+
+        // assert
+        result.Should().NotBeNullOrEmpty();
+        result.Should().Be(
+            $"<?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"no\"?><urlset xmlns:image=\"http://www.google.com/schemas/sitemap-image/1.1\" xmlns=\"http://www.sitemaps.org/schemas/sitemap/0.9\"><url><loc>{expectedUrl}</loc><lastmod>{now:yyyy-MM-dd}</lastmod><changefreq>{changeFrequency.ToString().ToLower()}</changefreq><priority>0.3</priority></url><url><loc>{expectedUrl}</loc><image:image><image:loc>{expectedUrl}</image:loc></image:image></url></urlset>");
+    }
+
     [Fact]
     public void Serialize_SitemapTooLarge_ThrowException()
     {

src/Sidio.Sitemap.Core/Extensions/SitemapImageLocation.cs

@@ -0,0 +1,26 @@
+namespace Sidio.Sitemap.Core.Extensions;
+
+/// <summary>
+/// Represents the location of an image in a sitemap.
+/// </summary>
+public sealed record SitemapImageLocation
+{
+    /// <summary>
+    /// Initializes a new instance of the <see cref="SitemapImageLocation"/> class.
+    /// </summary>
+    /// <param name="url">The URL of the page. This URL must begin with the protocol (such as http) and end with a trailing slash, if your web server requires it. This value must be less than 2,048 characters.</param>
+    public SitemapImageLocation(string url)
+    {
+        if (string.IsNullOrWhiteSpace(url))
+        {
+            throw new ArgumentNullException(nameof(url));
+        }
+
+        Url = url;
+    }
+
+    /// <summary>
+    /// Gets the image URL.
+    /// </summary>
+    public string Url { get; }
+}

src/Sidio.Sitemap.Core/Extensions/SitemapImageNode.cs

@@ -0,0 +1,55 @@
+namespace Sidio.Sitemap.Core.Extensions;
+
+/// <summary>
+/// Represents a node in a sitemap with images.
+/// </summary>
+public sealed record SitemapImageNode : ISitemapNode
+{
+    private const int MaxImages = 1000;
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="SitemapImageNode"/> class.
+    /// </summary>
+    /// <param name="url">The URL of the page. This URL must begin with the protocol (such as http) and end with a trailing slash, if your web server requires it. This value must be less than 2,048 characters.</param>
+    /// <param name="imageLocations">One or more image locations.</param>
+    /// <exception cref="ArgumentNullException">Thrown when a required argument is null or empty.</exception>
+    /// <exception cref="ArgumentException">Thrown when an argument has an invalid value.</exception>
+    public SitemapImageNode(string url, IEnumerable<SitemapImageLocation> imageLocations)
+    {
+        if (string.IsNullOrWhiteSpace(url))
+        {
+            throw new ArgumentNullException(nameof(url));
+        }
+
+        Url = url;
+        Images = imageLocations.ToList();
+
+        switch (Images.Count)
+        {
+            case 0:
+                throw new ArgumentException($"A {nameof(SitemapImageNode)} must contain at least one image location.", nameof(imageLocations));
+            case > MaxImages:
+                throw new ArgumentException($"A {nameof(SitemapImageNode)} must contain at most {MaxImages} image locations.", nameof(imageLocations));
+        }
+    }
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="SitemapImageNode"/> class.
+    /// </summary>
+    /// <param name="url">The URL of the page. This URL must begin with the protocol (such as http) and end with a trailing slash, if your web server requires it. This value must be less than 2,048 characters.</param>
+    /// <param name="imageLocation">An image locations.</param>
+    /// <exception cref="ArgumentNullException">Thrown when a required argument is null or empty.</exception>
+    /// <exception cref="ArgumentException">Thrown when an argument has an invalid value.</exception>
+    public SitemapImageNode(string url, SitemapImageLocation imageLocation)
+        : this(url, new[] { imageLocation })
+    {
+    }
+
+    /// <inheritdoc />
+    public string Url { get; }
+
+    /// <summary>
+    /// Gets the image locations.
+    /// </summary>
+    public IReadOnlyCollection<SitemapImageLocation> Images { get; }
+}

src/Sidio.Sitemap.Core/ISitemapNode.cs

@@ -0,0 +1,12 @@
+namespace Sidio.Sitemap.Core;
+
+/// <summary>
+/// Represents a node in a sitemap.
+/// </summary>
+public interface ISitemapNode
+{
+    /// <summary>
+    /// Gets the URL of the page. This URL must begin with the protocol (such as http) and end with a trailing slash, if your web server requires it. This value must be less than 2,048 characters.
+    /// </summary>
+    public string Url { get; }
+}

src/Sidio.Sitemap.Core/Serialization/SitemapExtensions.cs

@@ -0,0 +1,8 @@
+using Sidio.Sitemap.Core.Extensions;
+
+namespace Sidio.Sitemap.Core.Serialization;
+
+internal static class SitemapExtensions
+{
+    public static bool HasImageNodes(this Sitemap sitemap) => sitemap.Nodes.Any(node => node is SitemapImageNode);
+}

src/Sidio.Sitemap.Core/Serialization/XmlSerializer.cs

@@ -1,6 +1,7 @@
 using System.Globalization;
 using System.Text;
 using System.Xml;
+using Sidio.Sitemap.Core.Extensions;
 using Sidio.Sitemap.Core.Validation;
 
 namespace Sidio.Sitemap.Core.Serialization;
@@ -76,14 +77,33 @@ public Task<string> SerializeAsync(SitemapIndex sitemapIndex, CancellationToken
                 Encoding = new UTF8Encoding(true), Indent = false, OmitXmlDeclaration = false, NewLineHandling = NewLineHandling.None,
             };
 
+    private static void WriteNamespaces(XmlWriter writer, Sitemap sitemap)
+    {
+        if (sitemap.HasImageNodes())
+        {
+            writer.WriteAttributeString("xmlns", "image", null, "http://www.google.com/schemas/sitemap-image/1.1");
+        }
+    }
+
     private void SerializeSitemap(XmlWriter writer, Sitemap sitemap)
     {
         writer.WriteStartDocument(false);
         writer.WriteStartElement(null, "urlset", SitemapNamespace);
+        WriteNamespaces(writer, sitemap);
 
         foreach (var n in sitemap.Nodes)
         {
-            SerializeNode(writer, n);
+            switch (n)
+            {
+                case SitemapNode regularNode:
+                    SerializeNode(writer, regularNode);
+                    break;
+                case SitemapImageNode imageNode:
+                    SerializeNode(writer, imageNode);
+                    break;
+                default:
+                    throw new NotSupportedException($"The node type {n.GetType()} is not supported.");
+            }
         }
 
         writer.WriteEndElement();
@@ -113,6 +133,23 @@ private void SerializeNode(XmlWriter writer, SitemapNode node)
         writer.WriteEndElement();
     }
 
+    private void SerializeNode(XmlWriter writer, SitemapImageNode node)
+    {
+        var url = _urlValidator.Validate(node.Url);
+        writer.WriteStartElement("url");
+        writer.WriteElementString("loc", url.ToString());
+
+        foreach(var imageLocationNode in node.Images)
+        {
+            var imageUrl = _urlValidator.Validate(imageLocationNode.Url);
+            writer.WriteStartElement("image", "image", null);
+            writer.WriteElementString("image", "loc", null, imageUrl.ToString());
+            writer.WriteEndElement();
+        }
+
+        writer.WriteEndElement();
+    }
+
     private void SerializeSitemapIndex(XmlWriter writer, SitemapIndex sitemapIndex)
     {
         writer.WriteStartDocument(false);

src/Sidio.Sitemap.Core/Sitemap.cs

@@ -7,7 +7,7 @@ public sealed class Sitemap
 {
     internal const int MaxNodes = 50000;
 
-    private readonly List<SitemapNode> _nodes = new ();
+    private readonly List<ISitemapNode> _nodes = new ();
 
     /// <summary>
     /// Initializes a new instance of the <see cref="Sitemap"/> class.
@@ -21,7 +21,7 @@ public Sitemap()
     /// </summary>
     /// <param name="nodes">The sitemap nodes.</param>
     /// <exception cref="InvalidOperationException">Thrown when the number of nodes exceeds the maximum number of nodes.</exception>
-    public Sitemap(IEnumerable<SitemapNode> nodes)
+    public Sitemap(IEnumerable<ISitemapNode> nodes)
     {
         ArgumentNullException.ThrowIfNull(nodes);
         _nodes.AddRange(nodes);
@@ -31,14 +31,14 @@ public Sitemap(IEnumerable<SitemapNode> nodes)
     /// <summary>
     /// Gets the sitemap nodes.
     /// </summary>
-    public IReadOnlyList<SitemapNode> Nodes => _nodes;
+    public IReadOnlyList<ISitemapNode> Nodes => _nodes;
 
     /// <summary>
     /// Adds the specified nodes to the sitemap.
     /// </summary>
     /// <param name="nodes">The nodes.</param>
     /// <exception cref="InvalidOperationException">Thrown when the number of nodes exceeds the maximum number of nodes.</exception>
-    public void Add(params SitemapNode[] nodes)
+    public void Add(params ISitemapNode[] nodes)
     {
         ArgumentNullException.ThrowIfNull(nodes);
         Add(nodes.AsEnumerable());
@@ -49,7 +49,7 @@ public void Add(params SitemapNode[] nodes)
     /// </summary>
     /// <param name="nodes">The nodes.</param>
     /// <exception cref="InvalidOperationException">Thrown when the number of nodes exceeds the maximum number of nodes.</exception>
-    public void Add(IEnumerable<SitemapNode> nodes)
+    public void Add(IEnumerable<ISitemapNode> nodes)
     {
         ArgumentNullException.ThrowIfNull(nodes);
         _nodes.AddRange(nodes);

src/Sidio.Sitemap.Core/SitemapNode.cs

@@ -3,7 +3,7 @@
 /// <summary>
 /// Represents a node in a sitemap.
 /// </summary>
-public sealed record SitemapNode
+public sealed record SitemapNode : ISitemapNode
 {
     private decimal? _priority;
 
@@ -29,9 +29,7 @@ public SitemapNode(string? url, DateTime? lastModified = null, ChangeFrequency?
         LastModified = lastModified;
     }
 
-    /// <summary>
-    /// Gets the URL of the page. This URL must begin with the protocol (such as http) and end with a trailing slash, if your web server requires it. This value must be less than 2,048 characters.
-    /// </summary>
+    /// <inheritdoc />
     public string Url { get; }
 
     /// <summary>