Merge pull request #247 from SixLabors/js/insert-provider

Add InsertProvider extensions and tests

src/ImageSharp.Web/DependencyInjection/ImageSharpBuilderExtensions.cs

@@ -155,6 +155,45 @@ public static IImageSharpBuilder AddProvider<TProvider>(this IImageSharpBuilder
             return builder;
         }
 
+        /// <summary>
+        /// Inserts the given <see cref="IImageProvider"/> at the give index into to the provider collection within the service collection.
+        /// </summary>
+        /// <typeparam name="TProvider">The type of class implementing <see cref="IImageProvider"/>to add.</typeparam>
+        /// <param name="builder">The core builder.</param>
+        /// <param name="index">The zero-based index at which the provider should be inserted.</param>
+        /// <returns>The <see cref="IImageSharpBuilder"/>.</returns>
+        public static IImageSharpBuilder InsertProvider<TProvider>(this IImageSharpBuilder builder, int index)
+            where TProvider : class, IImageProvider
+        {
+            var descriptors = builder.Services.Where(x => x.ServiceType == typeof(IImageProvider)).ToList();
+            builder.ClearProviders();
+
+            descriptors.Insert(index, ServiceDescriptor.Singleton<IImageProvider, TProvider>());
+
+            builder.Services.TryAddEnumerable(descriptors);
+            return builder;
+        }
+
+        /// <summary>
+        /// Inserts the given <see cref="IImageProvider"/>  at the give index into the provider collection within the service collection.
+        /// </summary>
+        /// <typeparam name="TProvider">The type of class implementing <see cref="IImageProvider"/>to add.</typeparam>
+        /// <param name="builder">The core builder.</param>
+        /// <param name="index">The zero-based index at which the provider should be inserted.</param>
+        /// <param name="implementationFactory">The factory method for returning a <see cref="IImageProvider"/>.</param>
+        /// <returns>The <see cref="IImageSharpBuilder"/>.</returns>
+        public static IImageSharpBuilder InsertProvider<TProvider>(this IImageSharpBuilder builder, int index, Func<IServiceProvider, TProvider> implementationFactory)
+            where TProvider : class, IImageProvider
+        {
+            var descriptors = builder.Services.Where(x => x.ServiceType == typeof(IImageProvider)).ToList();
+            builder.ClearProviders();
+
+            descriptors.Insert(index, ServiceDescriptor.Singleton<IImageProvider>(implementationFactory));
+
+            builder.Services.TryAddEnumerable(descriptors);
+            return builder;
+        }
+
         /// <summary>
         /// Removes the given <see cref="IImageProvider"/> from the provider collection within the service collection.
         /// </summary>
@@ -166,7 +205,6 @@ public static IImageSharpBuilder RemoveProvider<TProvider>(this IImageSharpBuild
         {
             ServiceDescriptor descriptor = builder.Services.FirstOrDefault(x =>
                 x.ServiceType == typeof(IImageProvider)
-                && x.Lifetime == ServiceLifetime.Singleton
                 && (x.ImplementationType == typeof(TProvider)
                 || (x.ImplementationFactory?.GetMethodInfo().ReturnType == typeof(TProvider))));
 

tests/ImageSharp.Web.Tests/DependencyInjection/ServiceRegistrationExtensionsTests.cs

@@ -1,6 +1,8 @@
 // Copyright (c) Six Labors.
 // Licensed under the Apache License, Version 2.0.
 
+using System.Collections.Generic;
+using System.Linq;
 using System.Reflection;
 using Microsoft.Extensions.DependencyInjection;
 using SixLabors.ImageSharp.Web.Caching;
@@ -40,6 +42,8 @@ private static bool IsServiceImplementationFactory<TService, TImplementation>(Se
                (descriptor.ImplementationFactory?.GetMethodInfo().ReturnType == typeof(TImplementation) ||
                descriptor.ImplementationFactory?.Invoke(null)?.GetType() == typeof(TImplementation)); // OK to invoke the factory in tests
 
+        private static IReadOnlyList<ServiceDescriptor> GetCollection<T>(IServiceCollection serviceDescriptors) => serviceDescriptors.Where(x => x.ServiceType == typeof(T)).ToList();
+
         [Fact]
         public void DefaultServicesAreRegistered()
         {
@@ -174,6 +178,24 @@ public void CanAddRemoveImageProviders()
             Assert.DoesNotContain(services, IsService<IImageProvider, MockImageProvider>);
         }
 
+        [Fact]
+        public void CanInsertRemoveImageProviders()
+        {
+            var services = new ServiceCollection();
+            IImageSharpBuilder builder = services.AddImageSharp();
+
+            builder.InsertProvider<MockImageProvider>(0);
+            Assert.Single(services, IsService<IImageProvider, MockImageProvider>);
+            Assert.Single(services, IsServiceImplementationType<IImageProvider, MockImageProvider>);
+
+            IReadOnlyList<ServiceDescriptor> providers = GetCollection<IImageProvider>(services);
+            Assert.Equal(2, providers.Count);
+            Assert.True(IsService<IImageProvider, MockImageProvider>(providers[0]));
+
+            builder.RemoveProvider<MockImageProvider>();
+            Assert.DoesNotContain(services, IsService<IImageProvider, MockImageProvider>);
+        }
+
         [Fact]
         public void CanAddRemoveFactoryImageProviders()
         {
@@ -188,6 +210,25 @@ public void CanAddRemoveFactoryImageProviders()
             Assert.DoesNotContain(services, IsService<IImageProvider, MockImageProvider>);
         }
 
+        [Fact]
+        public void CanInsertRemoveFactoryImageProviders()
+        {
+            var services = new ServiceCollection();
+            IImageSharpBuilder builder = services.AddImageSharp();
+
+            builder.InsertProvider(0, _ => new MockImageProvider());
+            Assert.Single(services, IsService<IImageProvider, MockImageProvider>);
+            Assert.Single(services, IsServiceImplementationFactory<IImageProvider, MockImageProvider>);
+
+            IReadOnlyList<ServiceDescriptor> providers = GetCollection<IImageProvider>(services);
+            Assert.Equal(2, providers.Count);
+            Assert.True(IsService<IImageProvider, MockImageProvider>(providers[0]));
+            Assert.True(IsServiceImplementationFactory<IImageProvider, MockImageProvider>(providers[0]));
+
+            builder.RemoveProvider<MockImageProvider>();
+            Assert.DoesNotContain(services, IsService<IImageProvider, MockImageProvider>);
+        }
+
         [Fact]
         public void CanAddRemoveAllImageProviders()
         {