Add dependency injection and settings

Readme.md

@@ -1,5 +1,7 @@
 # AWS Lambda .Net Core Console Example
 
+This is a boilerplate function for those looking to create lambda functions with .Net Core.
+
 This starter project consists of:
 
 - Function.cs - class file containing a class with a single function handler method

src/lambda-dotnet-console/App.cs

@@ -0,0 +1,22 @@
+using System;
+
+namespace lambda_dotnet_console
+{
+    public class App
+    {
+        private AppSettings _settings;
+
+        public App(
+            AppSettings settings
+        )
+        {
+            _settings = settings ??
+                throw new ArgumentNullException(nameof(settings));
+        }
+
+        public string Run(string input)
+        {
+            return $"{_settings.Prefix}{input?.ToUpper()}";
+        }
+    }
+}

src/lambda-dotnet-console/Function.cs

@@ -1,12 +1,16 @@
 using System;
 using System.Collections.Generic;
+using System.IO;
 using System.Linq;
 using System.Threading.Tasks;
 
 using Amazon.Lambda.Core;
 
+using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.DependencyInjection;
+
 // Assembly attribute to enable the Lambda function's JSON input to be converted into a .NET class.
-[assembly: LambdaSerializer(typeof(Amazon.Lambda.Serialization.Json.JsonSerializer))]
+[assembly : LambdaSerializer(typeof(Amazon.Lambda.Serialization.Json.JsonSerializer))]
 
 namespace lambda_dotnet_console
 {
@@ -14,14 +18,34 @@ namespace lambda_dotnet_console
     {
 
         /// <summary>
-        /// A simple function that takes a string and does a ToUpper
+        /// Lamda Function
         /// </summary>
         /// <param name="input"></param>
         /// <param name="context"></param>
-        /// <returns></returns>
+        /// <returns>string</returns>
         public string FunctionHandler(string input, ILambdaContext context)
         {
-            return input?.ToUpper();
+            var configuration = new ConfigurationBuilder()
+                .SetBasePath(Directory.GetCurrentDirectory())
+                .AddJsonFile("appsettings.json", optional : false, reloadOnChange : true)
+                .AddEnvironmentVariables(prefix: "LAMBDA_")
+                .Build();
+
+            var serviceCollection = new ServiceCollection();
+            ConfigureServices(serviceCollection);
+
+            var appSettings = new AppSettings();
+            configuration.GetSection("App").Bind(appSettings);
+            serviceCollection.AddSingleton<AppSettings>(appSettings);
+
+            var serviceProvider = serviceCollection.BuildServiceProvider();
+            return serviceProvider.GetService<App>().Run(input);
+        }
+
+        private static void ConfigureServices(IServiceCollection serviceCollection)
+        {
+            serviceCollection.AddTransient<App>();
         }
     }
+
 }

src/lambda-dotnet-console/Settings/AppSettings.cs

@@ -0,0 +1,7 @@
+namespace lambda_dotnet_console
+{
+    public class AppSettings
+    {
+        public string Prefix { get; set; }
+    }
+}

src/lambda-dotnet-console/appsettings.json

@@ -0,0 +1,5 @@
+{
+  "App": {
+    "Prefix": "Test"
+  }
+}

src/lambda-dotnet-console/lambda-dotnet-console.csproj

@@ -1,14 +1,21 @@
 <Project Sdk="Microsoft.NET.Sdk">
-
   <PropertyGroup>
     <TargetFramework>netcoreapp2.1</TargetFramework>
     <GenerateRuntimeConfigurationFiles>true</GenerateRuntimeConfigurationFiles>
     <AWSProjectType>Lambda</AWSProjectType>
   </PropertyGroup>
-
   <ItemGroup>
-    <PackageReference Include="Amazon.Lambda.Core" Version="1.0.0" />
-    <PackageReference Include="Amazon.Lambda.Serialization.Json" Version="1.4.0" />
+    <PackageReference Include="Amazon.Lambda.Core" Version="1.0.0"/>
+    <PackageReference Include="Amazon.Lambda.Serialization.Json" Version="1.4.0"/>
+    <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="2.2.0"/>
+    <PackageReference Include="Microsoft.Extensions.Configuration.EnvironmentVariables" Version="2.2.0"/>
+    <PackageReference Include="Microsoft.Extensions.Options.ConfigurationExtensions" Version="2.2.0"/>
+    <PackageReference Include="Microsoft.Extensions.Configuration.FileExtensions" Version="2.2.0"/>
+    <PackageReference Include="Microsoft.Extensions.Configuration.Json" Version="2.2.0"/>
+    <PackageReference Include="Microsoft.Extensions.Configuration.CommandLine" Version="2.2.0"/>
+    <PackageReference Include="Microsoft.Extensions.Configuration.Binder" Version="2.2.0"/>
+  </ItemGroup>
+  <ItemGroup>
+    <None Include="appsettings.json" CopyToPublishDirectory="Always" CopyToOutputDirectory="PreserveNewest"/>
   </ItemGroup>
-
 </Project>

test/lambda-dotnet-console.Tests/FunctionTest.cs

@@ -3,12 +3,13 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Threading.Tasks;
 
-using Xunit;
 using Amazon.Lambda.Core;
 using Amazon.Lambda.TestUtilities;
 
 using lambda_dotnet_console;
 
+using Xunit;
+
 namespace lambda_dotnet_console.Tests
 {
     public class FunctionTest
@@ -22,7 +23,7 @@ namespace lambda_dotnet_console.Tests
             var context = new TestLambdaContext();
             var upperCase = function.FunctionHandler("hello world", context);
 
-            Assert.Equal("HELLO WORLD", upperCase);
+            Assert.Equal("TestHELLO WORLD", upperCase);
         }
     }
 }

test/lambda-dotnet-console.Tests/appsettings.json

@@ -0,0 +1,5 @@
+{
+  "App": {
+    "Prefix": "Test"
+  }
+}

test/lambda-dotnet-console.Tests/lambda-dotnet-console.Tests.csproj

@@ -17,5 +17,7 @@
   <ItemGroup>
     <ProjectReference Include="..\..\src\lambda-dotnet-console\lambda-dotnet-console.csproj" />
   </ItemGroup>
-
+  <ItemGroup>
+    <None Include="appsettings.json" CopyToPublishDirectory="Always" CopyToOutputDirectory="PreserveNewest"/>
+  </ItemGroup>
 </Project>