Merge pull request #76 from zadykian/feature/params-validation

Parameters validation via attributes

src/ConsoleAppFramework/ConsoleAppBuilder.cs

@@ -41,6 +41,7 @@ IHostBuilder AddConsoleAppFramework(IHostBuilder builder, string[] args, Console
                     configureOptions?.Invoke(ctx, options);
                     options.CommandLineArguments = args;
                     services.AddSingleton(options);
+                    services.AddSingleton<IParamsValidator, ParamsValidator>();
 
                     if (options.ReplaceToUseSimpleConsoleLogger)
                     {

src/ConsoleAppFramework/ConsoleAppEngine.cs

@@ -2,7 +2,9 @@
 using Microsoft.Extensions.Logging;
 using System;
 using System.Collections.Generic;
+using System.Collections.Immutable;
 using System.Collections.ObjectModel;
+using System.ComponentModel.DataAnnotations;
 using System.Linq;
 using System.Reflection;
 using System.Text.Json;
@@ -18,13 +20,20 @@ internal class ConsoleAppEngine
         readonly CancellationToken cancellationToken;
         readonly ConsoleAppOptions options;
         readonly IServiceProviderIsService isService;
+        readonly IParamsValidator paramsValidator;
         readonly bool isStrict;
 
-        public ConsoleAppEngine(ILogger<ConsoleApp> logger, IServiceProvider provider, ConsoleAppOptions options, IServiceProviderIsService isService, CancellationToken cancellationToken)
+        public ConsoleAppEngine(ILogger<ConsoleApp> logger,
+            IServiceProvider provider,
+            ConsoleAppOptions options,
+            IServiceProviderIsService isService,
+            IParamsValidator paramsValidator,
+            CancellationToken cancellationToken)
         {
             this.logger = logger;
             this.provider = provider;
             this.cancellationToken = cancellationToken;
+            this.paramsValidator = paramsValidator;
             this.options = options;
             this.isService = isService;
             this.isStrict = options.StrictOption;
@@ -168,6 +177,13 @@ async Task RunCore(Type type, MethodInfo methodInfo, object? instance, string?[]
                 invokeArgs = newInvokeArgs;
             }
 
+            var validationResult = paramsValidator.ValidateParameters(originalParameters.Zip(invokeArgs));
+            if (validationResult != ValidationResult.Success)
+            {
+                await SetFailAsync(validationResult!.ErrorMessage!);
+                return;
+            }
+
             try
             {
                 if (instance == null && !type.IsAbstract && !methodInfo.IsStatic)

src/ConsoleAppFramework/ParamsValidator.cs

@@ -0,0 +1,75 @@
+using System;
+using System.Collections.Generic;
+using System.Collections.Immutable;
+using System.ComponentModel.DataAnnotations;
+using System.Linq;
+using System.Reflection;
+
+namespace ConsoleAppFramework
+{
+	/// <summary>
+	/// Validator of command parameters.
+	/// </summary>
+	public interface IParamsValidator
+	{
+		/// <summary>
+		/// Validate <paramref name="parameters"/> of command based on validation attributes
+		/// applied to method's parameters.
+		/// </summary>
+		ValidationResult? ValidateParameters(IEnumerable<(ParameterInfo Parameter, object? Value)> parameters);
+	}
+
+	/// <inheritdoc />
+	public class ParamsValidator : IParamsValidator
+	{
+		private readonly ConsoleAppOptions options;
+
+		public ParamsValidator(ConsoleAppOptions options) => this.options = options;
+
+		/// <inheritdoc />
+		ValidationResult? IParamsValidator.ValidateParameters(
+			IEnumerable<(ParameterInfo Parameter, object? Value)> parameters)
+		{
+			var invalidParameters = parameters
+				.Select(tuple => (tuple.Parameter, tuple.Value, Result: Validate(tuple.Parameter, tuple.Value)))
+				.Where(tuple => tuple.Result != ValidationResult.Success)
+				.ToImmutableArray();
+
+			if (!invalidParameters.Any())
+			{
+				return ValidationResult.Success;
+			}
+
+			var errorMessage = string.Join(Environment.NewLine,
+				invalidParameters
+					.Select(tuple => 
+						$"{options.NameConverter(tuple.Parameter.Name!)} " +
+						$"({tuple.Value}): " +
+						$"{tuple.Result!.ErrorMessage}")
+			);
+
+			return new ValidationResult($"Some parameters have invalid values:{Environment.NewLine}{errorMessage}");
+		}
+
+		private static ValidationResult? Validate(ParameterInfo parameterInfo, object? value)
+		{
+			if (value is null) return ValidationResult.Success;
+
+			var validationContext = new ValidationContext(value, null, null);
+
+			var failedResults = GetValidationAttributes(parameterInfo)
+				.Select(attribute => attribute.GetValidationResult(value, validationContext))
+				.Where(result => result != ValidationResult.Success)
+				.ToImmutableArray();
+
+			return failedResults.Any()
+				? new ValidationResult(string.Join("; ", failedResults.Select(res => res?.ErrorMessage)))
+				: ValidationResult.Success;
+		}
+
+		private static IEnumerable<ValidationAttribute> GetValidationAttributes(ParameterInfo parameterInfo)
+			=> parameterInfo
+				.GetCustomAttributes()
+				.OfType<ValidationAttribute>();
+	}
+}

tests/ConsoleAppFramework.Tests/Integration/ValidationAttributeTests.cs

@@ -0,0 +1,65 @@
+using System;
+using System.ComponentModel.DataAnnotations;
+using FluentAssertions;
+using Xunit;
+
+// ReSharper disable UnusedMember.Global
+// ReSharper disable UnusedParameter.Global
+
+namespace ConsoleAppFramework.Integration.Test;
+
+public class ValidationAttributeTests
+{
+	/// <summary>
+	/// Try to execute command with invalid option value.
+	/// </summary>
+	[Fact]
+	public void Validate_String_Length_Test()
+	{
+		using var console = new CaptureConsoleOutput();
+
+		const string optionName = "arg";
+		const string optionValue = "too-large-string-value";
+
+		var args = new[] { nameof(AppWithValidationAttributes.StrLength), $"--{optionName}", optionValue };
+		ConsoleApp.Run<AppWithValidationAttributes>(args);
+
+		// Validation should fail, so StrLength command should not be executed.
+		console.Output.Should().NotContain(AppWithValidationAttributes.Output);
+
+		console.Output.Should().Contain(optionName);
+		console.Output.Should().Contain(optionValue);
+	}
+
+	[Fact]
+	public void Command_With_Multiple_Params()
+	{
+		using var console = new CaptureConsoleOutput();
+
+		var args = new[]
+		{
+			nameof(AppWithValidationAttributes.MultipleParams),
+			"--second-arg", "10",
+			"--first-arg", "invalid-email-address"
+		};
+
+		ConsoleApp.Run<AppWithValidationAttributes>(args);
+
+		// Validation should fail, so StrLength command should not be executed.
+		console.Output.Should().NotContain(AppWithValidationAttributes.Output);
+	}
+
+	/// <inheritdoc />
+	internal class AppWithValidationAttributes : ConsoleAppBase
+	{
+		public const string Output = $"hello from {nameof(AppWithValidationAttributes)}";
+
+		[Command(nameof(StrLength))]
+		public void StrLength([StringLength(maximumLength: 8)] string arg) => Console.WriteLine(Output);
+
+		[Command(nameof(MultipleParams))]
+		public void MultipleParams(
+			[EmailAddress] string firstArg,
+			[Range(0, 2)]  int secondArg) => Console.WriteLine(Output);
+	}
+}