Added link validation support

RELEASE.md

@@ -1,5 +1,6 @@
 # 1.0.0-alpha.8
 
+- Added support for validating links.
 - Refactored xref error messages to display for all documents at once (instead of one at a time).
 
 # 1.0.0-alpha.7

src/Statiq.Web/BootstrapperFactoryExtensions.cs

@@ -27,6 +27,7 @@ public static Bootstrapper CreateWeb(this BootstrapperFactory factory, string[]
                 .AddSettingsIfNonExisting(new Dictionary<string, object>
                 {
                     { WebKeys.MirrorResources, true },
+                    { WebKeys.ValidateRelativeLinks, true },
                     { WebKeys.Xref, Config.FromDocument(doc => doc.GetTitle().Replace(' ', '_')) }
                 });
     }

src/Statiq.Web/Pipelines/LinkValidation.cs

@@ -0,0 +1,28 @@
+using System.Linq;
+using Statiq.Common;
+using Statiq.Core;
+using Statiq.Html;
+
+namespace Statiq.Web.Pipelines
+{
+    public class LinkValidation : Pipeline
+    {
+        public LinkValidation()
+        {
+            Deployment = true;
+
+            ExecutionPolicy = ExecutionPolicy.Normal;
+
+            Dependencies.AddRange(nameof(Content), nameof(Archives));
+
+            OutputModules = new ModuleList
+            {
+                new ReplaceDocuments(Dependencies.ToArray()),
+                new ValidateLinks()
+                    .ValidateRelativeLinks(Config.FromSetting<bool>(WebKeys.ValidateRelativeLinks))
+                    .ValidateAbsoluteLinks(Config.FromSetting<bool>(WebKeys.ValidateAbsoluteLinks))
+                    .AsError(Config.FromSetting<bool>(WebKeys.ValidateLinksAsError))
+            };
+        }
+    }
+}

src/Statiq.Web/Pipelines/Sass.cs

@@ -1,15 +1,6 @@
-using System;
-using System.Collections.Generic;
-using System.Text;
-using Statiq.App;
-using Statiq.Common;
+using Statiq.Common;
 using Statiq.Core;
-using Statiq.Html;
-using Statiq.Less;
-using Statiq.Markdown;
-using Statiq.Razor;
 using Statiq.Sass;
-using Statiq.Yaml;
 
 namespace Statiq.Web.Pipelines
 {

src/Statiq.Web/WebKeys.cs

@@ -43,6 +43,21 @@ public static class WebKeys
 
         public const string MirrorResources = nameof(MirrorResources);
 
+        /// <summary>
+        /// Set to <c>true</c> (the default value is <c>false</c>) to validate all absolute links. Note that this may add considerable time to your generation process.
+        /// </summary>
+        public const string ValidateAbsoluteLinks = nameof(ValidateAbsoluteLinks);
+
+        /// <summary>
+        /// Set to <c>true</c> (the default value is <c>false</c>) to report errors on link validation failures.
+        /// </summary>
+        public const string ValidateLinksAsError = nameof(ValidateLinksAsError);
+
+        /// <summary>
+        /// Set to <c>true</c> (the default value) to validate all relative links.
+        /// </summary>
+        public const string ValidateRelativeLinks = nameof(ValidateRelativeLinks);
+
         // Intended for use as document metadata
 
         public const string ArchivePipelines = nameof(ArchivePipelines);