From 76462bf368e7388e7e0ef1b34874c1d85a183019 Mon Sep 17 00:00:00 2001
From: Macocian Alexandru Victor <amacocian@yahoo.com>
Date: Thu, 5 May 2022 08:10:30 +0200
Subject: [PATCH] Introduce priority for preferred constructor (#10)

---
 .../Models/ServiceWithPrefferedConstructor.cs | 16 +++++++++-
 Slim.Tests/ServiceManagerTests.cs             | 29 +++++++++++++++++++
 .../PrefferedConstructorAttribute.cs          | 11 +++++--
 Slim/ServiceManager.cs                        |  5 +++-
 Slim/Slim.csproj                              |  6 ++--
 Slim/Slim.xml                                 | 11 +++++--
 6 files changed, 67 insertions(+), 11 deletions(-)

diff --git a/Slim.Tests/Models/ServiceWithPrefferedConstructor.cs b/Slim.Tests/Models/ServiceWithPrefferedConstructor.cs
index 1a996a9..e9510e8 100644
--- a/Slim.Tests/Models/ServiceWithPrefferedConstructor.cs
+++ b/Slim.Tests/Models/ServiceWithPrefferedConstructor.cs
@@ -5,15 +5,29 @@ namespace Slim.Tests.Models
     public sealed class ServiceWithPrefferedConstructor
     {
         public bool CalledPrefferedConstructor { get; init; }
+        public bool CalledPrefferedConstructor0 { get; init; }
+        public bool CalledPrefferedConstructor1 { get; init; }
 
         public ServiceWithPrefferedConstructor()
         {
         }
 
-        [PrefferedConstructor]
+        [PreferredConstructor]
         public ServiceWithPrefferedConstructor(IIndependentService independentService)
         {
             this.CalledPrefferedConstructor = true;
         }
+
+        [PreferredConstructor(Priority = 0)]
+        public ServiceWithPrefferedConstructor(IDependentService dependentService)
+        {
+            this.CalledPrefferedConstructor0 = true;
+        }
+
+        [PreferredConstructor(Priority = 1)]
+        public ServiceWithPrefferedConstructor(IDependentService2 dependentService2)
+        {
+            this.CalledPrefferedConstructor1 = true;
+        }
     }
 }
diff --git a/Slim.Tests/ServiceManagerTests.cs b/Slim.Tests/ServiceManagerTests.cs
index 230633b..3011ae3 100644
--- a/Slim.Tests/ServiceManagerTests.cs
+++ b/Slim.Tests/ServiceManagerTests.cs
@@ -750,5 +750,34 @@ namespace Slim.Tests
 
             service.CalledPrefferedConstructor.Should().BeFalse();
         }
+
+        [TestMethod]
+        public void ServiceWithPrefferedConstructorCallsPrefferedConstructorWithHighestPriority()
+        {
+            var di = new ServiceManager();
+            di.RegisterSingleton<IIndependentService, IndependentService>();
+            di.RegisterSingleton<IndependentService>();
+            di.RegisterSingleton<IDependentService2, DependentService2>();
+            di.RegisterSingleton<IDependentService, DependentService>();
+            di.RegisterSingleton<ServiceWithPrefferedConstructor>();
+
+            var service = di.GetService<ServiceWithPrefferedConstructor>();
+
+            service.CalledPrefferedConstructor0.Should().BeTrue();
+        }
+
+        [TestMethod]
+        public void ServiceWithPrefferedConstructorCallsPrefferedConstructorWithSecondHighestPriority()
+        {
+            var di = new ServiceManager();
+            di.RegisterSingleton<IIndependentService, IndependentService>();
+            di.RegisterSingleton<IndependentService>();
+            di.RegisterSingleton<IDependentService2, DependentService2>();
+            di.RegisterSingleton<ServiceWithPrefferedConstructor>();
+
+            var service = di.GetService<ServiceWithPrefferedConstructor>();
+
+            service.CalledPrefferedConstructor1.Should().BeTrue();
+        }
     }
 }
diff --git a/Slim/Attributes/PrefferedConstructorAttribute.cs b/Slim/Attributes/PrefferedConstructorAttribute.cs
index 69ac125..5a31a07 100644
--- a/Slim/Attributes/PrefferedConstructorAttribute.cs
+++ b/Slim/Attributes/PrefferedConstructorAttribute.cs
@@ -6,12 +6,17 @@ namespace Slim.Attributes
     /// Attribute used to mark constructors to be used with priority by the <see cref="ServiceManager"/>.
     /// </summary>
     [AttributeUsage(AttributeTargets.Constructor)]
-    public sealed class PrefferedConstructorAttribute : Attribute
+    public sealed class PreferredConstructorAttribute : Attribute
     {
         /// <summary>
-        /// Creates a new instance of <see cref="PrefferedConstructorAttribute"/>.
+        /// Priority of the constructor. Constructors are ordered using this value when present.
         /// </summary>
-        public PrefferedConstructorAttribute()
+        public int Priority { get; set; } = int.MaxValue - 1;
+
+        /// <summary>
+        /// Creates a new instance of <see cref="PreferredConstructorAttribute"/>.
+        /// </summary>
+        public PreferredConstructorAttribute()
         {
         }
     }
diff --git a/Slim/ServiceManager.cs b/Slim/ServiceManager.cs
index dec503c..cb17524 100644
--- a/Slim/ServiceManager.cs
+++ b/Slim/ServiceManager.cs
@@ -687,7 +687,10 @@ namespace Slim
              * Order constructors to give priority to constructors that have PrefferedConstructorAttribute decorator
              */
             var constructors = implementType.GetConstructors()
-                .OrderBy(c => c.GetCustomAttribute<PrefferedConstructorAttribute>() is null);
+                .OrderBy(c => 
+                c.GetCustomAttribute<PreferredConstructorAttribute>() is PreferredConstructorAttribute preferredConstructorAttribute ?
+                preferredConstructorAttribute.Priority :
+                int.MaxValue);
             foreach (var constructor in constructors)
             {
                 /*
diff --git a/Slim/Slim.csproj b/Slim/Slim.csproj
index dcd92bc..fca1ae2 100644
--- a/Slim/Slim.csproj
+++ b/Slim/Slim.csproj
@@ -8,10 +8,10 @@
     <Company />
     <Product></Product>
     <Description>Service lifetime management and dependency injection framework.</Description>
-    <AssemblyVersion>1.7.1</AssemblyVersion>
-    <FileVersion>1.7.1</FileVersion>
+    <AssemblyVersion>1.7.2</AssemblyVersion>
+    <FileVersion>1.7.2</FileVersion>
     <PackageProjectUrl>https://github.com/AlexMacocian/Slim</PackageProjectUrl>
-    <Version>1.7.1</Version>
+    <Version>1.7.2</Version>
     <EnableNETAnalyzers>true</EnableNETAnalyzers>
     <PackageRequireLicenseAcceptance>true</PackageRequireLicenseAcceptance>
     <PackageLicenseFile>LICENSE</PackageLicenseFile>
diff --git a/Slim/Slim.xml b/Slim/Slim.xml
index 3347085..7b8c0f0 100644
--- a/Slim/Slim.xml
+++ b/Slim/Slim.xml
@@ -4,14 +4,19 @@
         <name>Slim</name>
     </assembly>
     <members>
-        <member name="T:Slim.Attributes.PrefferedConstructorAttribute">
+        <member name="T:Slim.Attributes.PreferredConstructorAttribute">
             <summary>
             Attribute used to mark constructors to be used with priority by the <see cref="T:Slim.ServiceManager"/>.
             </summary>
         </member>
-        <member name="M:Slim.Attributes.PrefferedConstructorAttribute.#ctor">
+        <member name="P:Slim.Attributes.PreferredConstructorAttribute.Priority">
             <summary>
-            Creates a new instance of <see cref="T:Slim.Attributes.PrefferedConstructorAttribute"/>.
+            Priority of the constructor. Constructors are ordered using this value when present.
+            </summary>
+        </member>
+        <member name="M:Slim.Attributes.PreferredConstructorAttribute.#ctor">
+            <summary>
+            Creates a new instance of <see cref="T:Slim.Attributes.PreferredConstructorAttribute"/>.
             </summary>
         </member>
         <member name="T:Slim.Exceptions.DependencyInjectionException">