Throw exception when unable to resolve service.

mayuki · Feb 4, 2020 · 494484a · 494484a
1 parent 5eecf52
commit 494484a
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Showing 3 changed files with 94 additions and 2 deletions.
diff --git a/src/Cocona.Lite/Lite/CoconaLiteInstanceActivator.cs b/src/Cocona.Lite/Lite/CoconaLiteInstanceActivator.cs
@@ -13,7 +13,7 @@ public class CoconaLiteInstanceActivator : ICoconaInstanceActivator
 
         public object? CreateInstance(IServiceProvider serviceProvider, Type instanceType, object[]? parameters)
         {
-            if (parameters != null && parameters.Length > 0) throw new ArgumentException("SimpleCoconaInstanceActivator doesn't support extra arguments.", nameof(parameters));
+            if (parameters != null && parameters.Length > 0) throw new NotSupportedException("SimpleCoconaInstanceActivator doesn't support extra arguments.");
             return SimpleActivator.CreateInstance(serviceProvider, instanceType);
         }
     }

diff --git a/src/Cocona.Lite/Lite/SimpleActivator.cs b/src/Cocona.Lite/Lite/SimpleActivator.cs
@@ -32,7 +32,8 @@ public static object CreateInstance(IServiceProvider serviceProvider, Type type)
 
             for (var i = 0; i < bestMatchCtorParameters.Length; i++)
             {
-                parameterValues[i] = serviceProvider.GetService(bestMatchCtorParameters[i].ParameterType);
+                var value = serviceProvider.GetService(bestMatchCtorParameters[i].ParameterType);
+                parameterValues[i] = value ?? throw new InvalidOperationException($"Unable to resolve service for type '{bestMatchCtorParameters[i].ParameterType.FullName}' while attempting to activate '{type.FullName}'");
             }
 
             return bestMatchCtor.Invoke(parameterValues);

diff --git a/test/Cocona.Lite.Test/CoconaLiteInstanceActivatorTest.cs b/test/Cocona.Lite.Test/CoconaLiteInstanceActivatorTest.cs
@@ -0,0 +1,91 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+using FluentAssertions;
+using Xunit;
+
+namespace Cocona.Lite.Test
+{
+    public class CoconaLiteInstanceActivatorTest
+    {
+        [Fact]
+        public void GetServiceOrCreateInstance_FromService()
+        {
+            var serviceProvider = new FakeServiceProvider();
+            serviceProvider.ValueByType[typeof(GetServiceOrCreateInstance_FromService_Target)] = new GetServiceOrCreateInstance_FromService_Target();
+
+            var activator = new CoconaLiteInstanceActivator();
+            var obj = activator.GetServiceOrCreateInstance(serviceProvider, typeof(GetServiceOrCreateInstance_FromService_Target));
+            obj.Should().Be(serviceProvider.ValueByType[typeof(GetServiceOrCreateInstance_FromService_Target)]);
+        }
+        class GetServiceOrCreateInstance_FromService_Target
+        { }
+
+        [Fact]
+        public void GetServiceOrCreateInstance_CreateInstance()
+        {
+            var serviceProvider = new FakeServiceProvider();
+
+            var activator = new CoconaLiteInstanceActivator();
+            var obj = activator.GetServiceOrCreateInstance(serviceProvider, typeof(GetServiceOrCreateInstance_CreateInstance_Target));
+            obj.Should().NotBeNull();
+        }
+        class GetServiceOrCreateInstance_CreateInstance_Target
+        { }
+
+        [Fact]
+        public void CreateInstance_Insufficient()
+        {
+            var serviceProvider = new FakeServiceProvider();
+
+            var activator = new CoconaLiteInstanceActivator();
+            var ex = Assert.Throws<InvalidOperationException>(() => activator.CreateInstance(serviceProvider, typeof(CreateInstance_NoAdditionalParameter_Target), Array.Empty<object>()));
+            ex.Message.Should().Be("Unable to resolve service for type 'System.String' while attempting to activate 'Cocona.Lite.Test.CoconaLiteInstanceActivatorTest+CreateInstance_NoAdditionalParameter_Target'");
+        }
+
+        [Fact]
+        public void CreateInstance_NoAdditionalParameter()
+        {
+            var serviceProvider = new FakeServiceProvider();
+            serviceProvider.ValueByType[typeof(int)] = 123;
+            serviceProvider.ValueByType[typeof(string)] = "Hello Konnichiwa!";
+
+            var activator = new CoconaLiteInstanceActivator();
+            var obj = activator.CreateInstance(serviceProvider, typeof(CreateInstance_NoAdditionalParameter_Target), Array.Empty<object>());
+            obj.Should().BeOfType<CreateInstance_NoAdditionalParameter_Target>();
+            ((CreateInstance_NoAdditionalParameter_Target)obj).Value0.Should().Be("Hello Konnichiwa!");
+            ((CreateInstance_NoAdditionalParameter_Target)obj).Value1.Should().Be(123);
+        }
+
+        [Fact]
+        public void CreateInstance_AdditionalParameter_NotSupported()
+        {
+            var serviceProvider = new FakeServiceProvider();
+
+            var activator = new CoconaLiteInstanceActivator();
+            var ex = Assert.Throws<NotSupportedException>(() => activator.CreateInstance(serviceProvider, typeof(CreateInstance_NoAdditionalParameter_Target), new object[] { 123, "Hello Konnichiwa!" }));
+        }
+
+        class CreateInstance_NoAdditionalParameter_Target
+        {
+            public string Value0;
+            public int Value1;
+
+            public CreateInstance_NoAdditionalParameter_Target(string value0, int value1)
+            {
+                Value0 = value0;
+                Value1 = value1;
+            }
+        }
+
+        class FakeServiceProvider : IServiceProvider
+        {
+            public Dictionary<Type, object> ValueByType { get; } = new Dictionary<Type, object>();
+
+            public object GetService(Type serviceType)
+            {
+                return ValueByType.TryGetValue(serviceType, out var value) ? value : default;
+            }
+        }
+    }
+}