From d3392b72997f96732667b3df83e4cb6f15d7db1b Mon Sep 17 00:00:00 2001
From: Damian Edwards <damian@damianedwards.com>
Date: Fri, 27 May 2022 15:18:31 -0700
Subject: [PATCH] Added MiniValidator.RequiresValidation() Bumped to version
 0.6.0

---
 src/Directory.Build.props           |  2 +-
 src/MiniValidation/MiniValidator.cs | 32 +++++++++++++++++++++++++++++
 2 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/src/Directory.Build.props b/src/Directory.Build.props
index 8ff139b..19d6030 100644
--- a/src/Directory.Build.props
+++ b/src/Directory.Build.props
@@ -1,7 +1,7 @@
 <Project>
 
   <PropertyGroup>
-    <VersionPrefix>0.5.1</VersionPrefix>
+    <VersionPrefix>0.6.0</VersionPrefix>
     <VersionSuffix Condition="'$(BuildNumber)' == ''">pre</VersionSuffix>
     <VersionSuffix Condition="'$(BuildNumber)' != ''">pre.$(BuildNumber)</VersionSuffix>
     <Authors>Damian Edwards</Authors>
diff --git a/src/MiniValidation/MiniValidator.cs b/src/MiniValidation/MiniValidator.cs
index b20a2f5..9b621ff 100644
--- a/src/MiniValidation/MiniValidator.cs
+++ b/src/MiniValidation/MiniValidator.cs
@@ -1,6 +1,7 @@
 using System;
 using System.Collections;
 using System.Collections.Generic;
+using System.Collections.ObjectModel;
 using System.ComponentModel.DataAnnotations;
 using System.Linq;
 using System.Resources;
@@ -15,6 +16,7 @@ namespace MiniValidation
     public static class MiniValidator
     {
         private static readonly TypeDetailsCache _typeDetailsCache = new();
+        private static readonly IDictionary<string, string[]> _emptyErrors = new ReadOnlyDictionary<string, string[]>(new Dictionary<string, string[]>());
 
         /// <summary>
         /// Gets or sets the maximum depth allowed when validating an object with recursion enabled.
@@ -22,6 +24,28 @@ public static class MiniValidator
         /// </summary>
         public static int MaxDepth { get; set; } = 32;
 
+        /// <summary>
+        /// Determines if the specified <see cref="Type"/> has anything to validate.
+        /// </summary>
+        /// <remarks>
+        /// Objects of types with nothing to validate will always return <c>true</c> when passed to <see cref="TryValidate(object, out IDictionary{string, string[]})"/>.
+        /// </remarks>
+        /// <param name="targetType">The <see cref="Type"/>.</param>
+        /// <param name="recurse"><c>true</c> to recursively check descendant types; if <c>false</c> only simple values directly on the target type are checked.</param>
+        /// <returns><c>true</c> if the <see cref="Type"/> has anything to validate, <c>false</c> if not.</returns>
+        /// <exception cref="ArgumentNullException"></exception>
+        public static bool RequiresValidation(Type targetType, bool recurse = true)
+        {
+            if (targetType == null)
+            {
+                throw new ArgumentNullException(nameof(targetType));
+            }
+
+            return typeof(IValidatableObject).IsAssignableFrom(targetType)
+                || (recurse && typeof(IEnumerable).IsAssignableFrom(targetType))
+                || _typeDetailsCache.Get(targetType).Any(p => p.HasValidationAttributes || recurse);
+        }
+
         /// <summary>
         /// Determines whether the specific object is valid. This method recursively validates descendant objects.
         /// </summary>
@@ -53,6 +77,14 @@ public static bool TryValidate(object target, bool recurse, out IDictionary<stri
                 throw new ArgumentNullException(nameof(target));
             }
 
+            if (!RequiresValidation(target.GetType(), recurse))
+            {
+                errors = _emptyErrors;
+
+                // Return true for types with nothing to validate
+                return true;
+            }
+
             var validatedObjects = new Dictionary<object, bool?>();
             var workingErrors = new Dictionary<string, List<string>>();
             var isValid = TryValidateImpl(target, recurse, workingErrors, validatedObjects);