Refactor the arguments enumeration

src/MGR.CommandLineParser/Arguments.cs

@@ -0,0 +1,64 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+
+namespace MGR.CommandLineParser
+{
+    internal class Arguments
+    {
+        private readonly List<string> _arguments;
+        private int _currentIndex = -1;
+        public Arguments(IEnumerable<string> args)
+        {
+            _arguments = new List<string>(args);
+        }
+
+        public void Revert()
+        {
+            _currentIndex = Math.Max(-1, _currentIndex - 1);
+        }
+
+        public bool Advance()
+        {
+            if (_arguments.Count == _currentIndex + 1)
+            {
+                return false;
+            }
+            _currentIndex++;
+            ReplaceRspFileInCurrentPosition();
+            return true;
+        }
+
+        private void ReplaceRspFileInCurrentPosition()
+        {
+            var current = GetCurrent();
+            if (current.StartsWith("@", StringComparison.CurrentCulture))
+            {
+                if (!current.StartsWith("@@", StringComparison.CurrentCulture))
+                {
+                    var responseFileName = current.Remove(0, 1);
+                    if (Path.GetExtension(responseFileName) == ".rsp" && File.Exists(responseFileName))
+                    {
+                        var responseFileContent = File.ReadAllLines(responseFileName);
+                        _arguments.RemoveAt(_currentIndex);
+                        _arguments.InsertRange(_currentIndex, responseFileContent);
+                        ReplaceRspFileInCurrentPosition();
+                        return;
+                    }
+                }
+                var currentWithoutAt = current.Remove(0, 1);
+                _arguments[_currentIndex] = currentWithoutAt;
+            }
+        }
+
+
+        public string GetCurrent()
+        {
+            if (_currentIndex < 0 || _currentIndex >= _arguments.Count)
+            {
+                throw new ArgumentOutOfRangeException();
+            }
+            return _arguments[_currentIndex];
+        }
+    }
+}

src/MGR.CommandLineParser/Constants.cs

@@ -19,6 +19,8 @@ internal static class ExceptionMessages
 
             internal static readonly Func<object, string, string> FormatParserOptionNotFoundForCommand =
                 (commandName, optionName) => string.Format(CultureInfo.InvariantCulture, "There is no option '{1}' for the command '{0}'.", commandName, optionName);
+            internal static readonly Func<object, string, string> FormatParserOptionValueNotFoundForCommand =
+                (commandName, optionName) => string.Format(CultureInfo.InvariantCulture, "A value should be provided for option '{1}' for the command '{0}'.", commandName, optionName);
 
             internal static readonly Func<object, string, string> FormatParserOptionValueRequired =
                 (commandName, optionName) => string.Format(CultureInfo.InvariantCulture, "You should specified a value for the option '{1}' of the command '{0}'.", commandName, optionName);

src/MGR.CommandLineParser/Parser.cs

@@ -24,31 +24,31 @@
 
         public string CommandLineName => _parserOptions.CommandLineName;
 
-        public async Task<ParsingResult> Parse<TCommand>(IEnumerable<string> arguments) where TCommand : class, ICommand => await ParseArguments(arguments, (parserEngine, argumentsEnumerator) =>
-                   parserEngine.Parse<TCommand>(argumentsEnumerator));
+        public async Task<ParsingResult> Parse<TCommand>(IEnumerable<string> args) where TCommand : class, ICommand => await ParseArguments(args, (parserEngine, arguments) =>
+                   parserEngine.Parse<TCommand>(arguments));
 
-        public async Task<ParsingResult> Parse(IEnumerable<string> arguments) => await ParseArguments(arguments, (parserEngine, argumentsEnumerator) =>
-                parserEngine.Parse(argumentsEnumerator));
+        public async Task<ParsingResult> Parse(IEnumerable<string> args) => await ParseArguments(args, (parserEngine, arguments) =>
+                parserEngine.Parse(arguments));
 
-        public async Task<ParsingResult> ParseWithDefaultCommand<TCommand>(IEnumerable<string> arguments) where TCommand : class, ICommand => await ParseArguments(arguments, (parserEngine, argumentsEnumerator) =>
-                    parserEngine.ParseWithDefaultCommand<TCommand>(argumentsEnumerator));
+        public async Task<ParsingResult> ParseWithDefaultCommand<TCommand>(IEnumerable<string> args) where TCommand : class, ICommand => await ParseArguments(args, (parserEngine, arguments) =>
+                    parserEngine.ParseWithDefaultCommand<TCommand>(arguments));
 
-        private async Task<ParsingResult> ParseArguments(IEnumerable<string> arguments, Func<ParserEngine, IEnumerator<string>, Task<ParsingResult>> callParse)
+        private async Task<ParsingResult> ParseArguments(IEnumerable<string> args, Func<ParserEngine, Arguments, Task<ParsingResult>> callParse)
         {
-            if (arguments == null)
+            if (args == null)
             {
                 return new ParsingResult(null, null, CommandParsingResultCode.NoArgumentsProvided);
             }
 
+            var arguments = new Arguments(args);
             var loggerFactory = _serviceProvider.GetService<ILoggerFactory>() ?? NullLoggerFactory.Instance;
             var logger = loggerFactory.CreateLogger<LoggerCategory.Parser>();
             using (logger.BeginParsingArguments(Guid.NewGuid().ToString()))
             {
                 logger.CreationOfParserEngine();
                 var parserEngine = new ParserEngine(_serviceProvider, loggerFactory);
-                var argumentsEnumerator = arguments.GetArgumentsEnumerator();
 
-                var result = await callParse(parserEngine, argumentsEnumerator);
+                var result = await callParse(parserEngine, arguments);
                 return result;
             }
         }

src/MGR.CommandLineParser/ParserEngine.cs

@@ -21,13 +21,13 @@
             _logger = loggerFactory.CreateLogger<LoggerCategory.Parser>();
         }
 
-        internal async Task<ParsingResult> Parse<TCommand>(IEnumerator<string> argumentsEnumerator) where TCommand : class, ICommand
+        internal async Task<ParsingResult> Parse<TCommand>(Arguments arguments) where TCommand : class, ICommand
         {
             using (_logger.BeginParsingForSpecificCommandType(typeof(TCommand)))
             {
                 var commandTypeProviders = _serviceProvider.GetServices<ICommandTypeProvider>();
                 var commandType = await commandTypeProviders.GetCommandType<TCommand>();
-                var parsingResult = ParseImpl(argumentsEnumerator, commandType);
+                var parsingResult = ParseImpl(arguments, commandType);
                 if (parsingResult.ParsingResultCode == CommandParsingResultCode.NoCommandFound)
                 {
                     _logger.NoCommandFoundAfterSpecificParsing();
@@ -42,46 +42,47 @@
             }
         }
 
-        internal async Task<ParsingResult> ParseWithDefaultCommand<TCommand>(IEnumerator<string> argumentsEnumerator)
+        internal async Task<ParsingResult> ParseWithDefaultCommand<TCommand>(Arguments arguments)
             where TCommand : class, ICommand
         {
             using (_logger.BeginParsingWithDefaultCommandType(typeof(TCommand)))
             {
-                var commandName = argumentsEnumerator.GetNextCommandLineItem();
-                if (commandName != null)
+                if (arguments.Advance())
                 {
+                    var commandName = arguments.GetCurrent();
                     _logger.ArgumentProvidedWithDefaultCommandType(commandName);
                     var commandTypeProviders = _serviceProvider.GetServices<ICommandTypeProvider>();
                     var commandType = await commandTypeProviders.GetCommandType(commandName);
                     if (commandType != null)
                     {
                         _logger.CommandTypeFoundWithDefaultCommandType(commandName);
-                        return ParseImpl(argumentsEnumerator, commandType);
+                        return ParseImpl(arguments, commandType);
                     }
 
                     _logger.NoCommandTypeFoundWithDefaultCommandType(commandName, typeof(TCommand));
-                    var withArgumentsCommandResult = await Parse<TCommand>(argumentsEnumerator.PrefixWith(commandName));
+                    arguments.Revert();
+                    var withArgumentsCommandResult = await Parse<TCommand>(arguments);
                     return withArgumentsCommandResult;
 
                 }
 
                 _logger.NoArgumentProvidedWithDefaultCommandType(typeof(TCommand));
-                var noArgumentsCommandResult = await Parse<TCommand>(argumentsEnumerator);
+                var noArgumentsCommandResult = await Parse<TCommand>(arguments);
                 return noArgumentsCommandResult;
             }
         }
 
-        internal async Task<ParsingResult> Parse(IEnumerator<string> argumentsEnumerator)
+        internal async Task<ParsingResult> Parse(Arguments arguments)
         {
             _logger.ParseForNotAlreadyKnownCommand();
-            var commandName = argumentsEnumerator.GetNextCommandLineItem();
-            if (commandName == null)
+            if (!arguments.Advance())
             {
                 _logger.NoCommandNameForNotAlreadyKnownCommand();
                 var helpWriter = _serviceProvider.GetRequiredService<IHelpWriter>();
                 await helpWriter.WriteCommandListing();
                 return new ParsingResult(null, null, CommandParsingResultCode.NoCommandNameProvided);
             }
+            var commandName = arguments.GetCurrent();
 
             using (_logger.BeginParsingUsingCommandName(commandName))
             {
@@ -96,14 +97,14 @@
                 }
 
                 _logger.CommandTypeFoundForNotAlreadyKnownCommand(commandName);
-                return ParseImpl(argumentsEnumerator, commandType);
+                return ParseImpl(arguments, commandType);
             }
 
         }
 
-        private ParsingResult ParseImpl(IEnumerator<string> argumentsEnumerator, ICommandType commandType)
+        private ParsingResult ParseImpl(Arguments arguments, ICommandType commandType)
         {
-            var commandObjectBuilder = ExtractCommandLineOptions(commandType, argumentsEnumerator);
+            var commandObjectBuilder = ExtractCommandLineOptions(commandType, arguments);
             if (commandObjectBuilder == null)
             {
                 return new ParsingResult(null, null, CommandParsingResultCode.CommandParametersNotValid);
@@ -118,21 +119,18 @@
             }
             return new ParsingResult(commandObjectBuilder.GenerateCommandObject(), null, CommandParsingResultCode.Success);
         }
-        private ICommandObjectBuilder ExtractCommandLineOptions(ICommandType commandType, IEnumerator<string> argumentsEnumerator)
+
+        private ICommandObjectBuilder ExtractCommandLineOptions(ICommandType commandType, Arguments arguments)
         {
             var commandObjectBuilder = commandType.CreateCommandObjectBuilder(_serviceProvider);
             if (commandObjectBuilder == null)
             {
                 return null;
             }
             var alwaysPutInArgumentList = false;
-            while (true)
+            while (arguments.Advance())
             {
-                var argument = argumentsEnumerator.GetNextCommandLineItem();
-                if (argument == null)
-                {
-                    break;
-                }
+                var argument = arguments.GetCurrent();
                 if (argument.Equals(Constants.EndOfOptions))
                 {
                     alwaysPutInArgumentList = true;
@@ -171,7 +169,17 @@
 
                 if (option.ShouldProvideValue)
                 {
-                    value = value ?? argumentsEnumerator.GetNextCommandLineItem();
+                    if (value == null)
+                    {
+                        if (!arguments.Advance())
+                        {
+                            var console = _serviceProvider.GetRequiredService<IConsole>();
+                            console.WriteLineError(Constants.ExceptionMessages.FormatParserOptionValueNotFoundForCommand(commandType.Metadata.Name, optionText));
+                            return null;
+                        }
+
+                        value = arguments.GetCurrent();
+                    }
                 }
 
                 option.AssignValue(value);

tests/MGR.CommandLineParser.IntegrationTests/DefaultCommand/SimpleOptionsTests.cs

@@ -0,0 +1,40 @@
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+using MGR.CommandLineParser.Extensibility.ClassBased;
+using MGR.CommandLineParser.Tests.Commands;
+using Xunit;
+
+namespace MGR.CommandLineParser.IntegrationTests.DefaultCommand
+{
+    public class SimpleOptionsTests : ConsoleLoggingTestsBase
+    {
+        [Fact]
+        public async Task ParseWithValidArgs()
+        {
+            // Arrange
+            IEnumerable<string> args = new[] { "--str-value:custom value", "-i", "42", "Custom argument value", "-b" };
+            var expectedReturnCode = CommandParsingResultCode.Success;
+            var expectedStrValue = "custom value";
+            var expectedNbOfArguments = 1;
+            var expectedArgumentsValue = "Custom argument value";
+            var expectedIntValue = 42;
+
+            // Act
+            var actual = await CallParseWithDefaultCommand<IntTestCommand>(args);
+
+            // Assert
+            Assert.True(actual.IsValid);
+            Assert.Equal(expectedReturnCode, actual.ParsingResultCode);
+            Assert.IsAssignableFrom<IClassBasedCommandObject>(actual.CommandObject);
+            Assert.IsType<IntTestCommand>(((IClassBasedCommandObject)actual.CommandObject).Command);
+            var rawCommand = (IntTestCommand)((IClassBasedCommandObject)actual.CommandObject).Command;
+            Assert.Equal(expectedStrValue, rawCommand.StrValue);
+            Assert.Equal(expectedIntValue, rawCommand.IntValue);
+            Assert.Null(rawCommand.IntListValue);
+            Assert.Equal(expectedNbOfArguments, rawCommand.Arguments.Count);
+            Assert.Equal(expectedArgumentsValue, rawCommand.Arguments.Single());
+            Assert.True(rawCommand.BoolValue);
+        }
+    }
+}