feat: Add slug for SEO friendly URL

* add BlogPostIdGenerator to generate shorter id

* add SeoFriendlyUrl prop to blog posts

* fix routing parameter

* fix RSS links

* refactor SeoFriendlyUrl property name

* unused NotMapped removed

* URL-Friendly removed from the RSS part

* BlogPostId value generator removed

* GenerateSearchEngineFriendlyUrl fixed

* make searchEngineFriendlyTitle optional

* renaming SearchEngineFriendlyUrl to Slug

* small refactoring in coding style

* removing id from slug generator

* generate Regex with source generators

* ShouldOpenBlogPost test fixed

* tests for slug added

* more testcase added for ShouldGenerateValidSlug

* small issue fixed in MatchIfSpecialCharactersExist Regex

Author: Kamyab7

src/LinkDotNet.Blog.Domain/BlogPost.cs

@@ -1,11 +1,14 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Collections.Immutable;
+using System.Globalization;
 using System.Linq;
+using System.Text;
+using System.Text.RegularExpressions;
 
 namespace LinkDotNet.Blog.Domain;
 
-public sealed class BlogPost : Entity
+public sealed partial class BlogPost : Entity
 {
     private BlogPost()
     {
@@ -35,6 +38,54 @@ private BlogPost()
 
     public string TagsAsString => Tags is null ? string.Empty : string.Join(", ", Tags);
 
+    public string Slug => GenerateSlug();
+
+    private string GenerateSlug()
+    {
+        // Remove all accents and make the string lower case.
+        if (string.IsNullOrWhiteSpace(Title))
+            return Title;
+
+        Title = Title.Normalize(NormalizationForm.FormD);
+        var chars = Title
+            .Where(c => CharUnicodeInfo.GetUnicodeCategory(c)
+            != UnicodeCategory.NonSpacingMark)
+            .ToArray();
+
+        Title = new string(chars).Normalize(NormalizationForm.FormC);
+
+        var slug = Title.ToLower(CultureInfo.CurrentCulture);
+
+        // Remove all special characters from the string.  
+        slug = MatchIfSpecialCharactersExist().Replace(slug, "");
+
+        // Remove all additional spaces in favour of just one.  
+        slug= MatchIfAdditionalSpacesExist().Replace(slug," ").Trim();
+
+        // Replace all spaces with the hyphen.  
+        slug= MatchIfSpaceExist().Replace(slug, "-");
+
+        return slug;
+    }
+
+    [GeneratedRegex(
+       @"[^A-Za-z0-9\s]",
+       RegexOptions.CultureInvariant,
+       matchTimeoutMilliseconds: 1000)]
+    private static partial Regex MatchIfSpecialCharactersExist();
+
+    [GeneratedRegex(
+       @"\s+",
+       RegexOptions.CultureInvariant,
+       matchTimeoutMilliseconds: 1000)]
+    private static partial Regex MatchIfAdditionalSpacesExist();
+
+    [GeneratedRegex(
+       @"\s",
+       RegexOptions.CultureInvariant,
+       matchTimeoutMilliseconds: 1000)]
+    private static partial Regex MatchIfSpaceExist();
+
     public static BlogPost Create(
         string title,
         string shortDescription,

src/LinkDotNet.Blog.Infrastructure/Persistence/Sql/Mapping/BlogPostConfiguration.cs

@@ -1,4 +1,4 @@
-using LinkDotNet.Blog.Domain;
+using LinkDotNet.Blog.Domain;
 using Microsoft.EntityFrameworkCore;
 using Microsoft.EntityFrameworkCore.Metadata.Builders;
 

src/LinkDotNet.Blog.Web/Features/Archive/ArchivePage.razor

@@ -21,12 +21,12 @@
             <ul class="ps-5">
                 @foreach (var blogPost in yearGroup.OrderByDescending(b => b.UpdatedDate))
                 {
-                    <li class="pt-1"><a href="/blogPost/@blogPost.Id">@blogPost.Title</a></li>
+                    <li class="pt-1"><a href="/blogPost/@blogPost.Id/@blogPost.Slug">@blogPost.Title</a></li>
                 }
             </ul>
         }
     }
-</div >
+</div>
 
 @code {
     private IReadOnlyCollection<IGrouping<int, BlogPostPerYear>> blogPostsPerYear;
@@ -35,7 +35,7 @@
     protected override async Task OnInitializedAsync()
     {
         var blogPosts = await Repository.GetAllByProjectionAsync(
-            p => new BlogPostPerYear(p.Id, p.Title, p.UpdatedDate),
+            p => new BlogPostPerYear(p.Id, p.Slug, p.Title, p.UpdatedDate),
             p => p.IsPublished);
         blogPostCount = blogPosts.Count;
         blogPostsPerYear = blogPosts
@@ -44,5 +44,5 @@
             .ToImmutableArray();
     }
 
-    private sealed record BlogPostPerYear(string Id, string Title, DateTime UpdatedDate);
+    private sealed record BlogPostPerYear(string Id, string Slug, string Title, DateTime UpdatedDate);
 }

src/LinkDotNet.Blog.Web/Features/Components/ShortBlogPost.razor

@@ -1,4 +1,4 @@
-@using System.Net
+@using System.Net
 @using System.Text.RegularExpressions
 @using System.Web
 @using LinkDotNet.Blog.Domain
@@ -43,7 +43,7 @@
 			<h2></h2>
 			<p>@MarkdownConverter.ToMarkupString(BlogPost.ShortDescription)</p>
 			<p class="read-more">
-				<a href="/blogPost/@BlogPost.Id" aria-label="@BlogPost.Title">Read the whole article</a>
+                <a href="/blogPost/@BlogPost.Id/@BlogPost.Slug" aria-label="@BlogPost.Title">Read the whole article</a>
 			</p>
 		</div>
 	</div>

src/LinkDotNet.Blog.Web/Features/ShowBlogPost/ShowBlogPostPage.razor

@@ -1,4 +1,4 @@
-@page "/blogPost/{blogPostId}"
+@page "/blogPost/{blogPostId}/{slug?}"
 @using Markdig
 @using LinkDotNet.Blog.Domain
 @using LinkDotNet.Blog.Infrastructure.Persistence
@@ -73,6 +73,9 @@ else
     [Parameter]
     public string BlogPostId { get; set; }
 
+    [Parameter]
+    public string Slug { get; set; }
+
 	private string OgDataImage => BlogPost.PreviewImageUrlFallback ?? BlogPost.PreviewImageUrl;
 
     private BlogPost BlogPost { get; set; }

tests/LinkDotNet.Blog.UnitTests/Domain/BlogPostTests.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Linq;
 using LinkDotNet.Blog.Domain;
 using LinkDotNet.Blog.TestUtilities;
@@ -24,6 +24,27 @@ public void ShouldUpdateBlogPost()
         blogPostToUpdate.PreviewImageUrlFallback.Should().Be("Url2");
         blogPostToUpdate.IsPublished.Should().BeTrue();
         blogPostToUpdate.Tags.Should().BeNullOrEmpty();
+        blogPostToUpdate.Slug.Should().NotBeNull();
+    }
+
+    [Theory]
+    [InlineData("blog title","blog-title")]
+    [InlineData("blog      title", "blog-title")]
+    [InlineData("blog +title", "blog-title")]
+    [InlineData("blog/title", "blogtitle")]
+    [InlineData("blog /title", "blog-title")]
+    [InlineData("BLOG TITLE", "blog-title")]
+    [InlineData("àccent", "accent")]
+    [InlineData("get 100$ quick", "get-100-quick")]
+    [InlineData("blog,title", "blogtitle")]
+    [InlineData("blog?!title", "blogtitle")]
+    [InlineData("blog----title", "blogtitle")]
+    [InlineData("überaus gut", "uberaus-gut")]
+    public void ShouldGenerateValidSlug(string title, string expectedSlug)
+    {
+        var blogPost = new BlogPostBuilder().WithTitle(title).Build();
+
+        blogPost.Slug.Should().Be(expectedSlug);
     }
 
     [Fact]

tests/LinkDotNet.Blog.UnitTests/Web/Features/Components/ShortBlogPostTests.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Linq;
 using LinkDotNet.Blog.TestUtilities;
 using LinkDotNet.Blog.Web.Features.Components;
@@ -17,7 +17,7 @@ public void ShouldOpenBlogPost()
 
         var readMore = cut.Find(".read-more a");
 
-        readMore.Attributes.Single(a => a.Name == "href").Value.Should().Be("/blogPost/SomeId");
+        readMore.Attributes.Single(a => a.Name == "href").Value.Should().Be("/blogPost/SomeId/blogpost");
     }
 
     [Fact]