feat(normalize): move normalization to parser, such that validator is…

… always validating strict. Add Strict-property (default true) to IbanAttribute and FluentValidator extension. When Strict=true, the input must strictly match the IBAN format rules. When Strict=false, whitespace is ignored and strict character casing enforcement is disabled (meaning, the user can input in lower and uppercase). This mode is a bit more forgiving when dealing with user-input. However it does require after successful validation, that you parse the user input with IIbanParser to normalize/sanitize the input and to be able to format the IBAN in correct electronic format.

See #93

src/IbanNet.DataAnnotations/IbanAttribute.cs

@@ -1,5 +1,6 @@
 using System.ComponentModel.DataAnnotations;
 using System.Globalization;
+using IbanNet.Internal;
 
 namespace IbanNet.DataAnnotations
 {
@@ -17,6 +18,14 @@ public IbanAttribute()
         {
         }
 
+        /// <summary>
+        /// Gets or sets whether to perform strict validation. When true, the input must strictly match the IBAN format rules.
+        /// When false, whitespace is ignored and strict character casing enforcement is disabled (meaning, the user can input in lower and uppercase). This mode is a bit more forgiving when dealing with user-input. However it does require after successful validation, that you parse the user input with <see cref="IIbanParser" /> to normalize/sanitize the input and to be able to format the IBAN in correct electronic format.
+        ///
+        /// <para>Default is <see langword="true" />. (this may change in future major release)</para>
+        /// </summary>
+        public bool Strict { get; init; } = true;
+
         /// <inheritdoc />
         protected override System.ComponentModel.DataAnnotations.ValidationResult? IsValid(object? value, ValidationContext validationContext)
         {
@@ -31,7 +40,11 @@ public IbanAttribute()
             }
 
             IIbanValidator ibanValidator = GetValidator(validationContext);
-            ValidationResult result = ibanValidator.Validate(strValue);
+            ValidationResult result = ibanValidator.Validate(
+                Strict
+                    ? strValue
+                    : InputNormalization.NormalizeOrNull(strValue)
+            );
             if (result.IsValid)
             {
                 return System.ComponentModel.DataAnnotations.ValidationResult.Success;
@@ -54,7 +67,7 @@ public IbanAttribute()
         /// <summary>
         /// Gets the validator from IoC container.
         /// </summary>
-        private static IIbanValidator GetValidator(IServiceProvider serviceProvider)
+        private static IIbanValidator GetValidator(IServiceProvider? serviceProvider)
         {
             var ibanValidator = (IIbanValidator?)serviceProvider?.GetService(typeof(IIbanValidator));
             if (ibanValidator is null)

src/IbanNet.DataAnnotations/IbanNet.DataAnnotations.csproj

@@ -12,6 +12,11 @@
     <PackageReadmeFile>README.md</PackageReadmeFile>
   </PropertyGroup>
 
+  <ItemGroup>
+    <Compile Include="..\IbanNet\Extensions\CharExtensions.cs" Link="Internal\Extensions\CharExtensions.cs" />
+    <Compile Include="..\IbanNet\Internal\InputNormalization.cs" Link="Internal\InputNormalization.cs" />
+  </ItemGroup>
+
   <ItemGroup>
     <None Include="README.md" Pack="true" PackagePath="\" />
   </ItemGroup>

src/IbanNet.FluentValidation/FluentIbanValidator.cs

@@ -1,5 +1,6 @@
 using FluentValidation;
 using FluentValidation.Validators;
+using IbanNet.Internal;
 
 namespace IbanNet.FluentValidation
 {
@@ -19,6 +20,14 @@ public FluentIbanValidator(IIbanValidator ibanValidator)
             _ibanValidator = ibanValidator ?? throw new ArgumentNullException(nameof(ibanValidator));
         }
 
+        /// <summary>
+        /// Gets or sets whether to perform strict validation. When true, the input must strictly match the IBAN format rules.
+        /// When false, whitespace is ignored and strict character casing enforcement is disabled (meaning, the user can input in lower and uppercase). This mode is a bit more forgiving when dealing with user-input. However it does require after successful validation, that you parse the user input with <see cref="IIbanParser" /> to normalize/sanitize the input and to be able to format the IBAN in correct electronic format.
+        ///
+        /// <para>Default is <see langword="true" />. (this may change in future major release)</para>
+        /// </summary>
+        public bool Strict { get; init; } = true;
+
         /// <inheritdoc />
         protected override string GetDefaultMessageTemplate(string errorCode)
         {
@@ -28,16 +37,20 @@ protected override string GetDefaultMessageTemplate(string errorCode)
         /// <inheritdoc />
         public override bool IsValid(ValidationContext<T> context, string value)
         {
-            // ReSharper disable once ConditionIsAlwaysTrueOrFalse
+            // ReSharper disable once ConditionIsAlwaysTrueOrFalseAccordingToNullableAPIContract
             if (value is null)
             {
                 return true;
             }
 
-            ValidationResult result = _ibanValidator.Validate(value);
+            ValidationResult result = _ibanValidator.Validate(
+                Strict
+                    ? value
+                    : InputNormalization.NormalizeOrNull(value)
+            );
             if (result.Error is not null)
             {
-                // ReSharper disable once ConstantConditionalAccessQualifier
+                // ReSharper disable once ConditionalAccessQualifierIsNonNullableAccordingToAPIContract
                 context?.MessageFormatter.AppendArgument("Error", result.Error);
             }
 

src/IbanNet.FluentValidation/IbanNet.FluentValidation.csproj

@@ -12,6 +12,11 @@
     <PackageReadmeFile>README.md</PackageReadmeFile>
   </PropertyGroup>
 
+  <ItemGroup>
+    <Compile Include="..\IbanNet\Extensions\CharExtensions.cs" Link="Internal\Extensions\CharExtensions.cs" />
+    <Compile Include="..\IbanNet\Internal\InputNormalization.cs" Link="Internal\InputNormalization.cs" />
+  </ItemGroup>
+
   <ItemGroup>
     <None Include="README.md" Pack="true" PackagePath="\" />
   </ItemGroup>

src/IbanNet.FluentValidation/RuleBuilderExtensions.cs

@@ -14,18 +14,26 @@ public static class RuleBuilderExtensions
         /// <typeparam name="T">Type of object being validated</typeparam>
         /// <param name="ruleBuilder">The rule builder on which the validator should be defined</param>
         /// <param name="ibanValidator">The <see cref="IIbanValidator" /> instance to use for validation.</param>
+        /// <param name="strict">
+        /// When true, the input must strictly match the IBAN format rules.
+        /// When false, whitespace is ignored and strict character casing enforcement is disabled (meaning, the user can input in lower and uppercase). This mode is a bit more forgiving when dealing with user-input. However it does require after successful validation, that you parse the user input with <see cref="IIbanParser" /> to normalize/sanitize the input and to be able to format the IBAN in correct electronic format.
+        ///
+        /// <para>Default is <see langword="true" />. (this may change in future major release)</para>
+        /// </param>
         /// <returns></returns>
         public static IRuleBuilderOptions<T, string> Iban<T>
         (
             this IRuleBuilder<T, string> ruleBuilder,
-            IIbanValidator ibanValidator)
+            IIbanValidator ibanValidator,
+            bool strict = true
+        )
         {
             if (ruleBuilder is null)
             {
                 throw new ArgumentNullException(nameof(ruleBuilder));
             }
 
-            return ruleBuilder.SetValidator(new FluentIbanValidator<T>(ibanValidator));
+            return ruleBuilder.SetValidator(new FluentIbanValidator<T>(ibanValidator) { Strict = strict });
         }
     }
 }

src/IbanNet/Iban.cs

@@ -1,8 +1,8 @@
 using System.ComponentModel;
 using System.Diagnostics;
-using System.Diagnostics.CodeAnalysis;
 using System.Globalization;
 using IbanNet.Extensions;
+using IbanNet.Internal;
 using IbanNet.Registry;
 using IbanNet.TypeConverters;
 
@@ -23,7 +23,7 @@ public sealed class Iban
         /// The maximum length of any IBAN, from any country.
         /// </summary>
         [DebuggerBrowsable(DebuggerBrowsableState.Never)]
-        internal const int MaxLength = 34;
+        public const int MaxLength = 34;
 
         [DebuggerBrowsable(DebuggerBrowsableState.Never)]
         private static readonly Func<IIbanValidator> DefaultFactory = () => new IbanValidator();
@@ -51,9 +51,12 @@ public static IIbanValidator Validator
                 : new Lazy<IIbanValidator>(() => value, true);
         }
 
-        internal Iban(string iban, IbanCountry ibanCountry)
+        internal Iban(string iban, IbanCountry ibanCountry, bool skipNormalize = false)
         {
-            _iban = NormalizeOrNull(iban) ?? throw new ArgumentNullException(nameof(iban));
+            _iban = (skipNormalize
+                    ? iban
+                    : InputNormalization.NormalizeOrNull(iban)
+                ) ?? throw new ArgumentNullException(nameof(iban));
             Country = ibanCountry ?? throw new ArgumentNullException(nameof(ibanCountry));
         }
 
@@ -221,56 +224,6 @@ public override int GetHashCode()
             return !Equals(left, right);
         }
 
-        /// <summary>
-        /// Normalizes an IBAN by removing whitespace, removing non-alphanumerics and upper casing each character.
-        /// </summary>
-        /// <param name="value">The input value to normalize.</param>
-        /// <returns>The normalized IBAN.</returns>
-        internal static string? NormalizeOrNull([NotNullIfNotNull("value")] string? value)
-        {
-            if (value is null)
-            {
-                return null;
-            }
-
-            int length = value.Length;
-#if USE_SPANS
-            // Use stack but clamp to avoid excessive stackalloc buffer.
-            const int stackallocMaxSize = MaxLength + 6;
-            Span<char> buffer = length <= stackallocMaxSize
-                ? stackalloc char[length]
-                : new char[length];
-#else
-            char[] buffer = new char[length];
-#endif
-            int pos = 0;
-            // ReSharper disable once ForCanBeConvertedToForeach - justification : performance
-            for (int i = 0; i < length; i++)
-            {
-                char ch = value[i];
-                if (ch.IsWhitespace())
-                {
-                    continue;
-                }
-
-                if (ch.IsAsciiLetter())
-                {
-                    // Inline upper case.
-                    buffer[pos++] = (char)(ch & ~' ');
-                }
-                else
-                {
-                    buffer[pos++] = ch;
-                }
-            }
-
-#if USE_SPANS
-            return new string(buffer[..pos]);
-#else
-            return new string(buffer, 0, pos);
-#endif
-        }
-
         private string? Extract(StructureSection? structure)
         {
             if (structure?.Pattern is null or NullPattern)

src/IbanNet/IbanParser.cs

@@ -1,5 +1,6 @@
 using System.Diagnostics.CodeAnalysis;
 using System.Globalization;
+using IbanNet.Internal;
 using IbanNet.Registry;
 
 namespace IbanNet
@@ -77,9 +78,11 @@ private bool TryParse(
             iban = null;
             exceptionThrown = null;
 
+            string? normalizedValue = InputNormalization.NormalizeOrNull(value);
+
             try
             {
-                validationResult = _ibanValidator.Validate(value);
+                validationResult = _ibanValidator.Validate(normalizedValue);
             }
             catch (Exception ex)
             {
@@ -93,7 +96,7 @@ private bool TryParse(
                 return false;
             }
 
-            iban = new Iban(validationResult.AttemptedValue!, validationResult.Country!);
+            iban = new Iban(normalizedValue!, validationResult.Country!, true);
             return true;
         }
     }

src/IbanNet/IbanValidator.cs

@@ -77,9 +77,7 @@ internal IbanValidator(IbanValidatorOptions options, IValidationRuleResolver val
         /// <returns>a validation result, indicating if the IBAN is valid or not</returns>
         public ValidationResult Validate(string? iban)
         {
-            string? normalizedIban = Iban.NormalizeOrNull(iban);
-
-            var context = new ValidationRuleContext(normalizedIban ?? string.Empty);
+            var context = new ValidationRuleContext(iban ?? string.Empty);
             ErrorResult? error = null;
 
             foreach (IIbanValidationRule rule in _rules)
@@ -101,7 +99,7 @@ public ValidationResult Validate(string? iban)
 
             return new ValidationResult
             {
-                AttemptedValue = normalizedIban,
+                AttemptedValue = iban,
                 Country = context.Country,
                 Error = error
             };

src/IbanNet/Internal/InputNormalization.cs

@@ -0,0 +1,57 @@
+using System.Diagnostics.CodeAnalysis;
+using IbanNet.Extensions;
+
+namespace IbanNet.Internal;
+
+internal static class InputNormalization
+{
+    /// <summary>
+    /// Normalizes an IBAN by removing whitespace, removing non-alphanumerics and upper casing each character.
+    /// </summary>
+    /// <param name="value">The input value to normalize.</param>
+    /// <returns>The normalized IBAN.</returns>
+    internal static string? NormalizeOrNull([NotNullIfNotNull("value")] string? value)
+    {
+        if (value is null)
+        {
+            return null;
+        }
+
+        int length = value.Length;
+#if USE_SPANS
+        // Use stack but clamp to avoid excessive stackalloc buffer.
+        const int stackallocMaxSize = Iban.MaxLength + 6;
+        Span<char> buffer = length <= stackallocMaxSize
+            ? stackalloc char[length]
+            : new char[length];
+#else
+            char[] buffer = new char[length];
+#endif
+        int pos = 0;
+        // ReSharper disable once ForCanBeConvertedToForeach - justification : performance
+        for (int i = 0; i < length; i++)
+        {
+            char ch = value[i];
+            if (ch.IsWhitespace())
+            {
+                continue;
+            }
+
+            if (ch.IsAsciiLetter())
+            {
+                // Inline upper case.
+                buffer[pos++] = (char)(ch & ~' ');
+            }
+            else
+            {
+                buffer[pos++] = ch;
+            }
+        }
+
+#if USE_SPANS
+        return new string(buffer[..pos]);
+#else
+            return new string(buffer, 0, pos);
+#endif
+    }
+}

test/IbanNet.DataAnnotations.Tests/AspNetIntegrationTest.cs

@@ -27,21 +27,21 @@ public async Task Given_valid_iban_when_posting_with_attribute_validation_it_sho
             using HttpClient client = _fixture.TestServer.CreateClient();
 
             // Act
-            HttpResponseMessage response = await client.SendAsync(CreateSaveRequest(validIban));
+            HttpResponseMessage response = await client.SendAsync(CreateSaveRequest(validIban, false));
 
             // Assert
             response.StatusCode.Should().Be(HttpStatusCode.OK);
             (await response.Content.ReadAsStringAsync()).Should().Be($"\"{validIban}\"");
         }
 
         [Fact]
-        public async Task Given_invalid_iban_when_posting_with_attribute_validation_it_should_validate()
+        public async Task Given_invalid_iban_when_posting_with_attribute_validation_it_should_not_validate()
         {
             const string invalidIban = "invalid-iban";
             using HttpClient client = _fixture.TestServer.CreateClient();
 
             // Act
-            HttpResponseMessage response = await client.SendAsync(CreateSaveRequest(invalidIban));
+            HttpResponseMessage response = await client.SendAsync(CreateSaveRequest(invalidIban, false));
 
             // Assert
             response.StatusCode.Should().Be(HttpStatusCode.BadRequest);
@@ -58,9 +58,9 @@ public async Task Given_invalid_iban_when_posting_with_attribute_validation_it_s
                 .Contain("The field 'BankAccountNumber' is not a valid IBAN.");
         }
 
-        private static HttpRequestMessage CreateSaveRequest(string iban)
+        private static HttpRequestMessage CreateSaveRequest(string iban, bool strict)
         {
-            return new(HttpMethod.Post, "test/save")
+            return new(HttpMethod.Post, "test/save" + (strict ? "-strict" : ""))
             {
                 Headers =
                 {

test/IbanNet.DataAnnotations.Tests/AspNetWebHostFixture.cs

@@ -1,9 +1,8 @@
 #if ASPNET_INTEGRATION_TESTS
+using IbanNet.DependencyInjection.ServiceProvider;
 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Hosting;
-using Microsoft.AspNetCore.Mvc;
 using Microsoft.Extensions.DependencyInjection;
-using Newtonsoft.Json;
 
 namespace IbanNet.DataAnnotations
 {
@@ -14,7 +13,7 @@ public void ConfigureServices(IServiceCollection services)
 #pragma warning restore CA1822 // Mark members as static
         {
             services
-                .AddSingleton<IIbanValidator, IbanValidator>()
+                .AddIbanNet()
                 .AddMvc()
                 .AddControllersAsServices();
         }