- Fully implement and document IsGuid validator.

Author: CodingFlow

CodingFlow.FluentValidation.UnitTests/GuidValidatorTests.cs

@@ -0,0 +1,38 @@
+using CodingFlow.FluentValidation.Validators;
+using FluentAssertions;
+using static CodingFlow.FluentValidation.Validations;
+
+namespace CodingFlow.FluentValidation.UnitTests;
+
+public class GuidValidatorTests
+{
+    [TestCase("019b87ad-c2c0-7a74-af4f-5fd1d80235be")]
+    [TestCase("019b87adc2c07a74af4f5fd1d80235be")]
+    public void Guid_Valid(string input)
+    {
+        var result = RuleFor(input)
+            .IsGuid()
+            .Result();
+
+        result.Should().BeEquivalentTo(new ValidationResult
+        {
+            IsValid = true,
+            Errors = []
+        });
+    }
+
+    [TestCase("100000000-0000-0000-0000-000000000000")]
+    [TestCase("0z000000-0000-0000-0000-000000000000")]
+    public void Guid_Invalid(string input)
+    {
+        var result = RuleFor(input)
+            .IsGuid()
+            .Result();
+
+        result.Should().BeEquivalentTo(new ValidationResult
+        {
+            IsValid = false,
+            Errors = [new() { Message = $"Value '{input}' is not a valid GUID." }]
+        });
+    }
+}

CodingFlow.FluentValidation/Validators/IsGuidValidator.cs

@@ -0,0 +1,26 @@
+namespace CodingFlow.FluentValidation.Validators;
+
+public static class IsGuidValidator
+{
+    /// <summary>
+    /// Ensures the string can be parsed into a valid GUID.
+    /// </summary>
+    /// <typeparam name="T">Input type.</typeparam>
+    /// <param name="validation"></param>
+    /// <param name="input">Value to compare against.</param>
+    /// <returns></returns>
+    public static FluentValidation<string> IsGuid(this FluentValidation<string> validation)
+    {
+        Validate(validation);
+
+        return validation;
+    }
+
+    private static void Validate(FluentValidation<string> validation)
+    {
+        validation.Validate(
+            validation => Guid.TryParse(validation.Input, out var value),
+            new ValidationError($"Value '{validation.Input}' is not a valid GUID.")
+        );
+    }
+}

Examples/Examples.csproj

@@ -15,6 +15,7 @@
 
   <ItemGroup>
     <ProjectReference Include="..\CodingFlow.FluentValidation.VogenExtensions\CodingFlow.FluentValidation.VogenExtensions.csproj" />
+    <ProjectReference Include="..\CodingFlow.FluentValidation\CodingFlow.FluentValidation.csproj" />
   </ItemGroup>
 
 </Project>

Examples/IsGuidBasicExample.cs

@@ -0,0 +1,18 @@
+using CodingFlow.FluentValidation.Validators;
+using static CodingFlow.FluentValidation.Validations;
+
+namespace Examples;
+
+internal class IsGuidBasicExample
+{
+    public void Run()
+    {
+        var input = "some string";
+
+        // begin-snippet: IsGuidBasicExample
+        RuleFor(input)
+            .IsGuid()
+            .Result();
+        // end-snippet
+    }
+}

README.md

@@ -120,6 +120,20 @@ RuleFor(input)
 <sup><a href='/Examples/MustBasicExample.cs#L12-L16' title='Snippet source file'>snippet source</a> | <a href='#snippet-MustBasicExample' title='Start of snippet'>anchor</a></sup>
 <!-- endSnippet -->
 
+## IsGuid Validator
+
+Ensures the string can be parsed into a valid GUID.
+
+<!-- snippet: IsGuidBasicExample -->
+<a id='snippet-IsGuidBasicExample'></a>
+```cs
+RuleFor(input)
+    .IsGuid()
+    .Result();
+```
+<sup><a href='/Examples/IsGuidBasicExample.cs#L12-L16' title='Snippet source file'>snippet source</a> | <a href='#snippet-IsGuidBasicExample' title='Start of snippet'>anchor</a></sup>
+<!-- endSnippet -->
+
 # Customizing
 
 ## Custom Error Messages

README.source.md

@@ -53,6 +53,12 @@ The predicate (aka `Must`) validator allows you to provide your own validation l
 
 snippet: MustBasicExample
 
+## IsGuid Validator
+
+Ensures the string can be parsed into a valid GUID.
+
+snippet: IsGuidBasicExample
+
 # Customizing
 
 ## Custom Error Messages