Make it possible to disable Examine indexes by composition (#18988)

src/Umbraco.Infrastructure/DependencyInjection/UmbracoBuilder.CoreServices.cs

@@ -186,7 +186,8 @@ public static partial class UmbracoBuilderExtensions
         builder.Services.AddTransient<IUserInviteSender, EmailUserInviteSender>();
         builder.Services.AddTransient<IUserForgotPasswordSender, EmailUserForgotPasswordSender>();
 
-        builder.Services.AddSingleton<IExamineManager, ExamineManager>();
+        builder.Services.AddSingleton<IExamineManager, NoopExamineManager>();
+        builder.Services.AddSingleton<IIndexRebuilder, NoopIndexRebuilder>();
 
         builder.Services.AddScoped<ITagQuery, TagQuery>();
 

src/Umbraco.Infrastructure/DependencyInjection/UmbracoBuilder.Examine.cs

@@ -1,3 +1,4 @@
+using Examine;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;
 using Umbraco.Cms.Core.DeliveryApi;
@@ -21,6 +22,8 @@ public static partial class UmbracoBuilderExtensions
 {
     public static IUmbracoBuilder AddExamine(this IUmbracoBuilder builder)
     {
+        builder.Services.AddUnique<IExamineManager, ExamineManager>();
+
         // populators are not a collection: one cannot remove ours, and can only add more
         // the container can inject IEnumerable<IIndexPopulator> and get them all
         builder.Services.AddSingleton<IIndexPopulator, MemberIndexPopulator>();

src/Umbraco.Infrastructure/Examine/NoopExamineManager.cs

@@ -0,0 +1,24 @@
+using Examine;
+
+namespace Umbraco.Cms.Infrastructure.Examine;
+
+internal sealed class NoopExamineManager : IExamineManager
+{
+    public void Dispose() {}
+
+    public bool TryGetIndex(string indexName, out IIndex index)
+    {
+        index = null!;
+        return false;
+    }
+
+    public bool TryGetSearcher(string searcherName, out ISearcher searcher)
+    {
+        searcher = null!;
+        return false;
+    }
+
+    public IEnumerable<IIndex> Indexes => Array.Empty<IIndex>();
+
+    public IEnumerable<ISearcher> RegisteredSearchers => Array.Empty<ISearcher>();
+}

src/Umbraco.Infrastructure/Examine/NoopIndexRebuilder.cs

@@ -0,0 +1,10 @@
+namespace Umbraco.Cms.Infrastructure.Examine;
+
+internal sealed class NoopIndexRebuilder : IIndexRebuilder
+{
+    public bool CanRebuild(string indexName) => false;
+
+    public void RebuildIndex(string indexName, TimeSpan? delay = null, bool useBackgroundThread = true) {}
+
+    public void RebuildIndexes(bool onlyEmptyIndexes, TimeSpan? delay = null, bool useBackgroundThread = true) {}
+}