Add support for using file-based C# Lambda functions

Author: normj

.gitignore

@@ -20,6 +20,7 @@
 
 **/node_modules/
 **/TestGenerations/
+**/artifacts/
 
 **/.vscode
 **/.idea

aws-extensions-for-dotnet-cli.sln

@@ -1,7 +1,7 @@
 
 Microsoft Visual Studio Solution File, Format Version 12.00
-# Visual Studio Version 17
-VisualStudioVersion = 17.1.32228.430
+# Visual Studio Version 18
+VisualStudioVersion = 18.3.11222.16 d18.3
 MinimumVisualStudioVersion = 10.0.40219.1
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "src", "src", "{A5EA2C7D-846F-4266-8423-EFC4BA0FE4B6}"
 EndProject
@@ -69,6 +69,13 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "TestIntegerFunction", "test
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "TestFunctionBuildProps", "testapps\TestFunctionBuildProps\TestFunctionBuildProps\TestFunctionBuildProps.csproj", "{AFA71B8E-F0AA-4704-8C4E-C11130F82B13}"
 EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "SingeFileLambdaFunctions", "SingeFileLambdaFunctions", "{5711F48F-5491-4C8A-92B2-4D6D849483B5}"
+	ProjectSection(SolutionItems) = preProject
+		testapps\SingeFileLambdaFunctions\serverless.template = testapps\SingeFileLambdaFunctions\serverless.template
+		testapps\SingeFileLambdaFunctions\ToUpperFunctionImplicitAOT.cs = testapps\SingeFileLambdaFunctions\ToUpperFunctionImplicitAOT.cs
+		testapps\SingeFileLambdaFunctions\ToUpperFunctionNoAOT.cs = testapps\SingeFileLambdaFunctions\ToUpperFunctionNoAOT.cs
+	EndProjectSection
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -207,6 +214,7 @@ Global
 		{69FFA03C-D29F-40E0-9E7F-572D5E10AF77} = {BB3CF729-8213-4DDD-85AE-A5E7754F3944}
 		{D7F1DFA4-066B-469C-B04C-DF032CF152C1} = {BB3CF729-8213-4DDD-85AE-A5E7754F3944}
 		{AFA71B8E-F0AA-4704-8C4E-C11130F82B13} = {BB3CF729-8213-4DDD-85AE-A5E7754F3944}
+		{5711F48F-5491-4C8A-92B2-4D6D849483B5} = {BB3CF729-8213-4DDD-85AE-A5E7754F3944}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {DBFC70D6-49A2-40A1-AB08-5D9504AB7112}

src/Amazon.Common.DotNetCli.Tools/Commands/BaseCommand.cs

@@ -30,7 +30,17 @@ public abstract class BaseCommand<TDefaultConfig> : ICommand
         public BaseCommand(IToolLogger logger, string workingDirectory)
         {
             this.Logger = logger;
-            this.WorkingDirectory = workingDirectory;
+
+            // In case working directory was set to a file then use the parent directory as the working directory.
+            // This can happen in the C# single file scenario.
+            if (File.Exists(workingDirectory))
+            {
+                this.WorkingDirectory = Directory.GetParent(workingDirectory).FullName;
+            }
+            else
+            {
+                this.WorkingDirectory = workingDirectory;
+            }
         }
 
         public BaseCommand(IToolLogger logger, string workingDirectory, IList<CommandOption> possibleOptions, string[] args)
@@ -753,7 +763,11 @@ private int WaitForIndexResponse(int min, int max)
 
 
         public IToolLogger Logger { get; protected set; }
-        public string WorkingDirectory { get; set; }
+        public string WorkingDirectory 
+        { 
+            get; 
+            set; 
+        }
 
         protected string GetUserAgentString()
         {