Move arg validation inside arg parsing

src/tye/CommonArguments.cs

@@ -0,0 +1,105 @@
+using System;
+using System.Collections.Generic;
+using System.CommandLine;
+using System.CommandLine.Parsing;
+using System.IO;
+
+namespace Tye
+{
+    internal static class CommonArguments
+    {
+        private static readonly string[] FileFormats = new[] { "tye.yaml", "tye.yml", "*.csproj", "*.fsproj", "*.sln" };
+
+        public static Argument<FileInfo> Path_Optional
+        {
+            get
+            {
+                return new Argument<FileInfo>((r) => TryParsePath(r, required: false), isDefault: true)
+                {
+                    Arity = ArgumentArity.ZeroOrOne,
+                    Description = "file or directory, can be a yaml, sln, or project file",
+                    Name = "path",
+                };
+            }
+        }
+
+        public static Argument<FileInfo> Path_Required
+        {
+            get
+            {
+                return new Argument<FileInfo>((r) => TryParsePath(r, required: true), isDefault: true)
+                {
+                    Arity = ArgumentArity.ZeroOrOne,
+                    Description = "file or directory, can be a yaml, sln, or project file",
+                    Name = "path",
+                };
+            }
+        }
+
+        public static bool TryFindSupportedFile(string directoryPath, out string? filePath, out string? errorMessage)
+        {
+            foreach (var format in FileFormats)
+            {
+                var files = Directory.GetFiles(directoryPath, format);
+
+                if (files.Length == 1)
+                {
+                    errorMessage = null;
+                    filePath = files[0];
+                    return true;
+                }
+
+                if (files.Length > 1)
+                {
+                    errorMessage = $"More than one matching files was found in directory '{directoryPath}'.";
+                    filePath = default;
+                    return false;
+                }
+            }
+
+            errorMessage = $"No project project file or solution was found in directory '{directoryPath}'.";
+            filePath = default;
+            return false;
+        }
+
+        static FileInfo TryParsePath(ArgumentResult result, bool required)
+        {
+            var token = result.Tokens.Count switch
+            {
+                0 => ".",
+                1 => result.Tokens[0].Value,
+                _ => throw new InvalidOperationException("Unexpected token count."),
+            };
+
+            if (string.IsNullOrEmpty(token))
+            {
+                token = ".";
+            }
+
+            if (File.Exists(token))
+            {
+                return new FileInfo(token);
+            }
+
+            if (Directory.Exists(token))
+            {
+                if (TryFindSupportedFile(token, out var filePath, out var errorMessage))
+                {
+                    return new FileInfo(filePath);
+                }
+                else if (required)
+                {
+                    result.ErrorMessage = errorMessage;
+                    return default!;
+                }
+                else
+                {
+                    return default!;
+                }
+            }
+
+            result.ErrorMessage = $"The file '{token}' could not be found.";
+            return default!;
+        }
+    }
+}

src/tye/Program.DeployCommand.cs

@@ -13,26 +13,22 @@ namespace Tye
     {
         public static Command CreateDeployCommand()
         {
-            var command = new Command("deploy", "Deploy the application");
-
-            var argument = new Argument("path")
+            var command = new Command("deploy", "Deploy the application")
             {
-                Description = "A solution or project file to generate a yaml manifest from",
-                Arity = ArgumentArity.ZeroOrOne
+                CommonArguments.Path_Required,
+                StandardOptions.Interactive,
+                StandardOptions.Verbosity,
             };
 
-            command.Add(argument);
-            command.Add(StandardOptions.Interactive);
-            command.Add(StandardOptions.Verbosity);
-
-            command.Handler = CommandHandler.Create<IConsole, string, Verbosity, bool>((console, path, verbosity, interactive) =>
+            command.Handler = CommandHandler.Create<IConsole, FileInfo, Verbosity, bool>((console, path, verbosity, interactive) =>
             {
-                var application = ResolveApplication(path);
-                if (application is null)
+                // Workaround for https://github.com/dotnet/command-line-api/issues/723#issuecomment-593062654
+                if (path is null)
                 {
-                    throw new CommandException($"None of the supported files were found (tye.yaml, .csproj, .fsproj, .sln)");
+                    throw new CommandException("No project or solution file was found.");
                 }
 
+                var application = ResolveApplication(path);
                 return ExecuteAsync(new OutputContext(console, verbosity), application, environment: "production", interactive);
             });
 

src/tye/Program.InitCommand.cs

@@ -16,22 +16,17 @@ namespace Tye
         {
             var command = new Command("init", "create a yaml manifest")
             {
+                CommonArguments.Path_Optional,
             };
 
-            var argument = new Argument("path")
+            command.Handler = CommandHandler.Create<IConsole, FileInfo?>((console, path) =>
             {
-                Description = "A solution or project file to generate a yaml manifest from",
-                Arity = ArgumentArity.ZeroOrOne
-            };
-
-            command.AddArgument(argument);
-
-            command.Handler = CommandHandler.Create<IConsole, string>((console, path) =>
-            {
-                if (File.Exists("tye.yaml"))
+                if (path is FileInfo &&
+                    path.Exists &&
+                    (string.Equals(".yml", path.Extension, StringComparison.OrdinalIgnoreCase) ||
+                    string.Equals(".yaml", path.Extension, StringComparison.OrdinalIgnoreCase)))
                 {
-                    console.Out.WriteLine("\"tye.yaml\" already exists.");
-                    return;
+                    throw new CommandException($"File '{path.FullName}' already exists.");
                 }
 
                 var template = @"- name: app
@@ -46,39 +41,32 @@ namespace Tye
     # - port: 8080 # number port of the binding
 ";
 
-                try
+                if (path is FileInfo && path.Exists)
                 {
                     var application = ResolveApplication(path);
-                    if (application is object)
-                    {
-                        var serializer = new SerializerBuilder()
-                            .WithNamingConvention(CamelCaseNamingConvention.Instance)
-                            .ConfigureDefaultValuesHandling(DefaultValuesHandling.OmitDefaults)
-                            .Build();
+                    var serializer = new SerializerBuilder()
+                        .WithNamingConvention(CamelCaseNamingConvention.Instance)
+                        .ConfigureDefaultValuesHandling(DefaultValuesHandling.OmitDefaults)
+                        .Build();
 
-                        var extension = Path.GetExtension(application.Source).ToLowerInvariant();
-                        var directory = Path.GetDirectoryName(application.Source);
-                        var descriptions = application.Services.Select(s => s.Value.Description).ToList();
+                    var extension = path.Extension.ToLowerInvariant();
+                    var directory = path.Directory;
+                    var descriptions = application.Services.Select(s => s.Value.Description).ToList();
 
-                        // Clear all bindings if any for solutions and project files
-                        if (extension == ".sln" || extension == ".csproj" || extension == ".fsproj")
+                    // Clear all bindings if any for solutions and project files
+                    if (extension == ".sln" || extension == ".csproj" || extension == ".fsproj")
+                    {
+                        foreach (var d in descriptions)
                         {
-                            foreach (var d in descriptions)
-                            {
-                                d.Bindings = null;
-                                d.Replicas = null;
-                                d.Build = null;
-                                d.Configuration = null;
-                                d.Project = d.Project.Substring(directory.Length).TrimStart(Path.DirectorySeparatorChar);
-                            }
+                            d.Bindings = null;
+                            d.Replicas = null;
+                            d.Build = null;
+                            d.Configuration = null;
+                            d.Project = d.Project.Substring(directory.FullName.Length).TrimStart(Path.DirectorySeparatorChar);
                         }
-
-                        template = serializer.Serialize(descriptions);
                     }
-                }
-                catch (FileNotFoundException)
-                {
-                    // No file found, just generate a new one
+
+                    template = serializer.Serialize(descriptions);
                 }
 
                 File.WriteAllText("tye.yaml", template);
@@ -88,66 +76,29 @@ namespace Tye
             return command;
         }
 
-        private static Application? ResolveApplication(string? path)
+        private static Application ResolveApplication(FileInfo file)
         {
-            if (string.IsNullOrEmpty(path))
-            {
-                path = ResolveFileFromDirectory(Directory.GetCurrentDirectory());
-            }
-            else if (Directory.Exists(path))
+            if (!file.Exists)
             {
-                path = ResolveFileFromDirectory(Path.GetFullPath(path));
+                throw new FileNotFoundException($"File '{file.FullName}' does not exist");
             }
 
-            if (path == null)
-            {
-                return null;
-            }
-
-            if (!File.Exists(path))
-            {
-                throw new FileNotFoundException($"{path} does not exist");
-            }
-
-            switch (Path.GetExtension(path).ToLower())
+            switch (file.Extension.ToLower())
             {
                 case ".yaml":
                 case ".yml":
-                    return Application.FromYaml(path);
+                    return Application.FromYaml(file.FullName);
 
                 case ".csproj":
                 case ".fsproj":
-                    return Application.FromProject(path);
+                    return Application.FromProject(file.FullName);
 
                 case ".sln":
-                    return Application.FromSolution(path);
+                    return Application.FromSolution(file.FullName);
 
                 default:
-                    throw new NotSupportedException($"{path} not supported");
+                    throw new NotSupportedException($"File '{file.FullName}' is not a supported format.");
             }
         }
-
-        private static string? ResolveFileFromDirectory(string basePath)
-        {
-            var formats = new[] { "tye.yaml", "tye.yml", "*.csproj", "*.fsproj", "*.sln" };
-
-            foreach (var format in formats)
-            {
-                var files = Directory.GetFiles(basePath, format);
-                if (files.Length == 0)
-                {
-                    continue;
-                }
-
-                if (files.Length > 1)
-                {
-                    throw new InvalidOperationException($"Ambiguous match found {string.Join(", ", files.Select(Path.GetFileName))}");
-                }
-
-                return files[0];
-            }
-
-            return null;
-        }
     }
 }

src/tye/Program.RunCommand.cs

@@ -1,6 +1,7 @@
 using System;
 using System.CommandLine;
 using System.CommandLine.Invocation;
+using System.IO;
 using Micronetes.Hosting;
 
 namespace Tye
@@ -11,12 +12,7 @@ namespace Tye
         {
             var command = new Command("run", "run the application")
             {
-            };
-
-            var argument = new Argument("path")
-            {
-                Description = "A file or directory to execute. Supports a project files, solution files or a yaml manifest.",
-                Arity = ArgumentArity.ZeroOrOne
+                CommonArguments.Path_Required,
             };
 
             // TODO: We'll need to support a --build-args
@@ -53,16 +49,15 @@ namespace Tye
                 Required = false
             });
 
-            command.AddArgument(argument);
-
-            command.Handler = CommandHandler.Create<IConsole, string>((console, path) =>
+            command.Handler = CommandHandler.Create<IConsole, FileInfo>((console, path) =>
             {
-                var application = ResolveApplication(path);
-                if (application is null)
+                // Workaround for https://github.com/dotnet/command-line-api/issues/723#issuecomment-593062654
+                if (path is null)
                 {
-                    throw new CommandException($"None of the supported files were found (tye.yaml, .csproj, .fsproj, .sln)");
+                    throw new CommandException("No project or solution file was found.");
                 }
 
+                var application = ResolveApplication(path);
                 return MicronetesHost.RunAsync(application, args);
             });
 

src/tye/Program.cs

@@ -5,6 +5,7 @@ using System.CommandLine.Help;
 using System.CommandLine.Invocation;
 using System.CommandLine.IO;
 using System.CommandLine.Parsing;
+using System.Reflection;
 using System.Threading.Tasks;
 
 namespace Tye
@@ -48,6 +49,12 @@ namespace Tye
             context.Console.ResetTerminalForegroundColor();
             context.Console.SetTerminalForegroundColor(ConsoleColor.Red);
 
+            if (exception is TargetInvocationException tie &&
+                tie.InnerException is object)
+            {
+                exception = tie.InnerException;
+            }
+
             if (exception is OperationCanceledException)
             {
                 context.Console.Error.WriteLine("Oh dear! Operation canceled.");