Fixed: throw at startup when multiple controllers are registered for the same resource type

Author: Bart Koelman

src/JsonApiDotNetCore/Middleware/JsonApiRoutingConvention.cs

@@ -81,6 +81,11 @@ public void Apply(ApplicationModel application)
 
                         if (resourceType != null)
                         {
+                            if (_controllerPerResourceTypeMap.ContainsKey(resourceType))
+                            {
+                                throw new InvalidConfigurationException($"Multiple controllers found for resource type '{resourceType}'.");
+                            }
+
                             _resourceTypePerControllerTypeMap.Add(controller.ControllerType, resourceType);
                             _controllerPerResourceTypeMap.Add(resourceType, controller);
                         }

test/JsonApiDotNetCoreTests/IntegrationTests/NonJsonApiControllers/DuplicateKnownResourcesController.cs

@@ -0,0 +1,16 @@
+using JsonApiDotNetCore.Configuration;
+using JsonApiDotNetCore.Controllers;
+using JsonApiDotNetCore.Services;
+using Microsoft.Extensions.Logging;
+
+namespace JsonApiDotNetCoreTests.IntegrationTests.NonJsonApiControllers
+{
+    public sealed class DuplicateKnownResourcesController : JsonApiController<KnownResource, int>
+    {
+        public DuplicateKnownResourcesController(IJsonApiOptions options, IResourceGraph resourceGraph, ILoggerFactory loggerFactory,
+            IResourceService<KnownResource, int> resourceService)
+            : base(options, resourceGraph, loggerFactory, resourceService)
+        {
+        }
+    }
+}

test/JsonApiDotNetCoreTests/IntegrationTests/NonJsonApiControllers/DuplicateResourceControllerTests.cs

@@ -0,0 +1,32 @@
+using System;
+using FluentAssertions;
+using JsonApiDotNetCore.Errors;
+using TestBuildingBlocks;
+using Xunit;
+
+namespace JsonApiDotNetCoreTests.IntegrationTests.NonJsonApiControllers
+{
+    public sealed class DuplicateResourceControllerTests : IntegrationTestContext<TestableStartup<KnownDbContext>, KnownDbContext>
+    {
+        public DuplicateResourceControllerTests()
+        {
+            UseController<KnownResourcesController>();
+            UseController<DuplicateKnownResourcesController>();
+        }
+
+        [Fact]
+        public void Fails_at_startup_when_multiple_controllers_exist_for_same_resource_type()
+        {
+            // Act
+            Action action = () => _ = Factory;
+
+            // Assert
+            action.Should().ThrowExactly<InvalidConfigurationException>().WithMessage("Multiple controllers found for resource type 'knownResources'.");
+        }
+
+        public override void Dispose()
+        {
+            // Prevents crash when test cleanup tries to access lazily constructed Factory.
+        }
+    }
+}

test/JsonApiDotNetCoreTests/IntegrationTests/NonJsonApiControllers/NonJsonApiDbContext.cs renamed to test/JsonApiDotNetCoreTests/IntegrationTests/NonJsonApiControllers/EmptyDbContext.cs

@@ -4,9 +4,9 @@
 namespace JsonApiDotNetCoreTests.IntegrationTests.NonJsonApiControllers
 {
     [UsedImplicitly(ImplicitUseTargetFlags.Members)]
-    public sealed class NonJsonApiDbContext : DbContext
+    public sealed class EmptyDbContext : DbContext
     {
-        public NonJsonApiDbContext(DbContextOptions<NonJsonApiDbContext> options)
+        public EmptyDbContext(DbContextOptions<EmptyDbContext> options)
             : base(options)
         {
         }

test/JsonApiDotNetCoreTests/IntegrationTests/NonJsonApiControllers/KnownDbContext.cs

@@ -0,0 +1,16 @@
+using JetBrains.Annotations;
+using Microsoft.EntityFrameworkCore;
+
+namespace JsonApiDotNetCoreTests.IntegrationTests.NonJsonApiControllers
+{
+    [UsedImplicitly(ImplicitUseTargetFlags.Members)]
+    public sealed class KnownDbContext : DbContext
+    {
+        public DbSet<KnownResource> KnownResources => Set<KnownResource>();
+
+        public KnownDbContext(DbContextOptions<KnownDbContext> options)
+            : base(options)
+        {
+        }
+    }
+}

test/JsonApiDotNetCoreTests/IntegrationTests/NonJsonApiControllers/KnownResource.cs

@@ -0,0 +1,13 @@
+using JetBrains.Annotations;
+using JsonApiDotNetCore.Resources;
+using JsonApiDotNetCore.Resources.Annotations;
+
+namespace JsonApiDotNetCoreTests.IntegrationTests.NonJsonApiControllers
+{
+    [UsedImplicitly(ImplicitUseTargetFlags.Members)]
+    [Resource(ControllerNamespace = "JsonApiDotNetCoreTests.IntegrationTests.NonJsonApiControllers")]
+    public sealed class KnownResource : Identifiable<int>
+    {
+        public string? Value { get; set; }
+    }
+}

test/JsonApiDotNetCoreTests/IntegrationTests/NonJsonApiControllers/NonJsonApiControllerTests.cs

@@ -8,11 +8,11 @@
 
 namespace JsonApiDotNetCoreTests.IntegrationTests.NonJsonApiControllers
 {
-    public sealed class NonJsonApiControllerTests : IClassFixture<IntegrationTestContext<TestableStartup<NonJsonApiDbContext>, NonJsonApiDbContext>>
+    public sealed class NonJsonApiControllerTests : IClassFixture<IntegrationTestContext<TestableStartup<EmptyDbContext>, EmptyDbContext>>
     {
-        private readonly IntegrationTestContext<TestableStartup<NonJsonApiDbContext>, NonJsonApiDbContext> _testContext;
+        private readonly IntegrationTestContext<TestableStartup<EmptyDbContext>, EmptyDbContext> _testContext;
 
-        public NonJsonApiControllerTests(IntegrationTestContext<TestableStartup<NonJsonApiDbContext>, NonJsonApiDbContext> testContext)
+        public NonJsonApiControllerTests(IntegrationTestContext<TestableStartup<EmptyDbContext>, EmptyDbContext> testContext)
         {
             _testContext = testContext;
 

test/JsonApiDotNetCoreTests/IntegrationTests/NonJsonApiControllers/UnknownResourceControllerTests.cs

@@ -6,7 +6,7 @@
 
 namespace JsonApiDotNetCoreTests.IntegrationTests.NonJsonApiControllers
 {
-    public sealed class UnknownResourceControllerTests : IntegrationTestContext<TestableStartup<NonJsonApiDbContext>, NonJsonApiDbContext>
+    public sealed class UnknownResourceControllerTests : IntegrationTestContext<TestableStartup<EmptyDbContext>, EmptyDbContext>
     {
         public UnknownResourceControllerTests()
         {