Merge pull request #5 from StevanFreeborn/stevanfreeborn/feat/add-rss-feed

feat: add rss feed

.vscode/settings.json

@@ -2,6 +2,7 @@
   "cSpell.words": [
     "Antiforgery",
     "blazor",
+    "Entitize",
     "Hsts",
     "Markdig",
     "msedge"

src/Blog/Blog.csproj

@@ -9,6 +9,7 @@
 
   <ItemGroup>
     <PackageReference Include="Markdig" Version="0.36.2" />
+    <PackageReference Include="System.ServiceModel.Syndication" Version="8.0.0" />
     <PackageReference Include="TestableIO.System.IO.Abstractions.Wrappers" Version="21.0.2" />
     <PackageReference Include="WebStoating.Markdig.Prism" Version="1.0.0" />
   </ItemGroup>

src/Blog/GlobalUsings.cs

@@ -1,5 +1,9 @@
 global using System.IO.Abstractions;
+global using System.ServiceModel.Syndication;
+global using System.Text;
 global using System.Text.Json;
+global using System.Xml;
+global using System.Xml.Linq;
 
 global using Blog.Components;
 global using Blog.Posts;

src/Blog/Posts/FilePostService.cs

@@ -16,7 +16,7 @@ class FilePostService(
     .UseAdvancedExtensions()
     .UsePrism()
     .Build();
-  
+
   private const string MetaFence = "meta";
   private const string IndexFile = "index.md";
 
@@ -68,12 +68,12 @@ class FilePostService(
       try
       {
         var indexFilePath = _fileSystem.Path.Combine(subDirectory, IndexFile);
-        
+
         if (_fileSystem.File.Exists(indexFilePath) is false)
         {
           continue;
         }
-        
+
         var postText = await _fileSystem.File.ReadAllTextAsync(indexFilePath);
 
         var (metaContent, document) = ParsePost(postText);
@@ -108,7 +108,7 @@ class FilePostService(
 
   public async Task<PostWithContent?> GetPostAsync(string slug)
   {
-    try 
+    try
     {
       var postPath = _fileSystem.Path.Combine(_options.PostsDirectory, slug, IndexFile);
 
@@ -133,10 +133,10 @@ class FilePostService(
         return null;
       }
 
-      var postWithContent = post with 
-      { 
+      var postWithContent = post with
+      {
         Slug = slug,
-        Content = document.ToHtml(MarkdownPipeline) 
+        Content = document.ToHtml(MarkdownPipeline)
       };
 
       return postWithContent;

src/Blog/Program.cs

@@ -21,11 +21,73 @@ app.UseHttpsRedirection();
 app.UseStaticFiles();
 app.UseAntiforgery();
 
+app.UseStatusCodePagesWithRedirects("/Error/{0}");
+
+app
+  .MapGet("/rss", async (HttpContext context, IPostService postService) =>
+  {
+    var req = context.Request;
+    var url = $"{req.Scheme}://{req.Host}{req.PathBase}";
+
+    var posts = await postService.GetPostsAsync();
+
+    var items = posts.Select(post =>
+    {
+      var uri = new Uri($"{url}/{post.Slug}");
+
+      var item = new SyndicationItem(
+        post.Title,
+        post.Lead,
+        uri,
+        post.Slug,
+        post.PublishedAt
+      );
+
+      return item;
+    });
+
+    var feed = new SyndicationFeed(
+      "journal",
+      "A blog by Stevan Freeborn",
+      new Uri(url)
+    )
+    {
+      Items = items,
+    };
+
+    XNamespace atom = "http://www.w3.org/2005/Atom";
+    feed.ElementExtensions.Add(
+      new XElement(atom + "link",
+        new XAttribute("href", url + "/rss"),
+        new XAttribute("rel", "self"),
+        new XAttribute("type", "application/rss+xml")
+      )
+    );
+
+    var settings = new XmlWriterSettings
+    {
+      Encoding = Encoding.UTF8,
+      NewLineHandling = NewLineHandling.Entitize,
+      Indent = true,
+      Async = true,
+    };
+
+    using var stream = new MemoryStream();
+    using var writer = XmlWriter.Create(stream, settings);
+
+    var rssFormatter = new Rss20FeedFormatter(feed, false);
+    rssFormatter.WriteTo(writer);
+    await writer.FlushAsync();
+
+    return Results.File(stream.ToArray(), "application/xml");
+  })
+  .WithDisplayName("RSS Feed")
+  .WithDescription("RSS feed for the blog");
+
 app
   .MapRazorComponents<App>()
   .AddInteractiveServerRenderMode();
 
-app.UseStatusCodePagesWithRedirects("/Error/{0}");
 
 app.Run();
 

test/Blog.Tests/EndToEnd/BlogTest.cs

@@ -32,7 +32,7 @@ public class BlogTest : PageTest
   {
     await Context.Tracing.StopAsync(new()
     {
-        Path = Path.Combine(
+      Path = Path.Combine(
             TestContext.CurrentContext.WorkDirectory,
             "playwright-traces",
             $"{TestContext.CurrentContext.Test.ClassName}.{TestContext.CurrentContext.Test.Name}.zip"

test/Blog.Tests/EndToEnd/CompositeHost.cs

@@ -6,20 +6,20 @@ public class CompositeHost(IHost testHost, IHost kestrelHost) : IHost
   private readonly IHost _kestrelHost = kestrelHost;
 
   public IServiceProvider Services => _testHost.Services;
-  
+
   public void Dispose()
   {
     _testHost.Dispose();
     _kestrelHost.Dispose();
     GC.SuppressFinalize(this);
   }
-  
+
   public async Task StartAsync(CancellationToken cancellationToken = default)
   {
     await _testHost.StartAsync(cancellationToken);
     await _kestrelHost.StartAsync(cancellationToken);
   }
-  
+
   public async Task StopAsync(CancellationToken cancellationToken = default)
   {
     await _testHost.StopAsync(cancellationToken);

test/Blog.Tests/EndToEnd/PostTests.cs

@@ -1,7 +1,7 @@
 namespace Blog.Tests.EndToEnd;
 
 [TestFixture]
-public class PostTests : BlogTest 
+public class PostTests : BlogTest
 {
   private const string TestPostSlug = "test-blog";
   private const string TestPostTitle = "Test Blog";

test/Blog.Tests/EndToEnd/RssTests.cs

@@ -0,0 +1,32 @@
+namespace Blog.Tests.EndToEnd;
+
+[TestFixture]
+public class RssTests : BlogTest
+{
+  [Test]
+  public async Task Task_Rss_WhenFetched_ItShouldReturnRssFeed()
+  {
+    var response = await Page.APIRequest.GetAsync("/rss");
+    response.Status.Should().Be((int)HttpStatusCode.OK);
+
+    var xml = await response.BodyAsync();
+
+    var streamReader = new StreamReader(
+      new MemoryStream(xml),
+      Encoding.UTF8
+    );
+
+
+    var settings = new XmlReaderSettings
+    {
+      Async = true
+    };
+
+    using var xmlReader = XmlReader.Create(streamReader, settings);
+    var feed = SyndicationFeed.Load(xmlReader);
+
+    feed.Title.Text.Should().Be("journal");
+    feed.Description.Text.Should().Be("A blog by Stevan Freeborn");
+    feed.Items.Should().HaveCount(2);
+  }
+}

test/Blog.Tests/GlobalUsings.cs

@@ -1,5 +1,8 @@
 global using System.IO.Abstractions;
 global using System.Net;
+global using System.ServiceModel.Syndication;
+global using System.Text;
+global using System.Xml;
 
 global using Blog.Posts;
 
@@ -10,10 +13,10 @@ global using Microsoft.AspNetCore.Hosting.Server;
 global using Microsoft.AspNetCore.Mvc.Testing;
 global using Microsoft.Extensions.DependencyInjection;
 global using Microsoft.Extensions.Hosting;
+global using Microsoft.Extensions.Logging;
 global using Microsoft.Extensions.Options;
 global using Microsoft.Playwright;
 global using Microsoft.Playwright.NUnit;
-global using Microsoft.Extensions.Logging;
 
 global using Moq;
 

test/Blog.Tests/Unit/FilePostServiceTests.cs

@@ -15,7 +15,7 @@ class FilePostServiceTests
       .Returns(new FilePostServiceOptions { PostsDirectory = "posts" });
 
     _sut = new FilePostService(
-      _mockOptions.Object, 
+      _mockOptions.Object,
       _mockFileSystem.Object,
       _mockLogger.Object
     );
@@ -326,8 +326,8 @@ class FilePostServiceTests
     _mockFileSystem
       .Setup(x => x.Directory.GetDirectories(It.IsAny<string>()))
       .Returns([
-        "valid-blog-post", 
-        "another-valid-blog-post", 
+        "valid-blog-post",
+        "another-valid-blog-post",
         "invalid-blog-post"
       ]);