Add a factory method for creating the CompositeValidatorSelector (#1988)

Changelog.txt

@@ -1,5 +1,6 @@
 11.2.0 - 8 August 2022
 Resolve issue with unexpected results when with nested Include calls with the MemberNameValidatorSelector (#1989)
+Add a new Selector Factory for the Composite Selector (#1988)
 
 11.1.1 - 6 August 2022
 Fix issue with incorrect rulesets being executed in a child validator when combined with ChildRules (#1981)

src/FluentValidation/Internal/ValidationStrategy.cs

@@ -141,7 +141,7 @@ public class ValidationStrategy<T> {
 				selectors.Add(ValidatorOptions.Global.ValidatorSelectors.RulesetValidatorSelectorFactory(_ruleSets.ToArray()));
 			}
 
-			selector = selectors.Count == 1 ? selectors[0] : new CompositeValidatorSelector(selectors);
+			selector = selectors.Count == 1 ? selectors[0] : ValidatorOptions.Global.ValidatorSelectors.CompositeValidatorSelectorFactory(selectors);
 		}
 		else {
 			selector = ValidatorOptions.Global.ValidatorSelectors.DefaultValidatorSelectorFactory();

src/FluentValidation/ValidatorOptions.cs

@@ -233,13 +233,14 @@ public class ValidatorSelectorOptions {
 	private Func<IValidatorSelector> _defaultValidatorSelector = () => DefaultSelector;
 	private Func<IEnumerable<string>, IValidatorSelector> _memberNameValidatorSelector = properties => new MemberNameValidatorSelector(properties);
 	private Func<IEnumerable<string>, IValidatorSelector> _rulesetValidatorSelector = ruleSets => new RulesetValidatorSelector(ruleSets);
+	private Func<IEnumerable<IValidatorSelector>, IValidatorSelector> _compositeValidatorSelectorFactory = selectors => new CompositeValidatorSelector(selectors);
 
 	/// <summary>
 	/// Factory func for creating the default validator selector
 	/// </summary>
 	public Func<IValidatorSelector> DefaultValidatorSelectorFactory {
 		get => _defaultValidatorSelector;
-		set => _defaultValidatorSelector = value ?? (() => new DefaultValidatorSelector());
+		set => _defaultValidatorSelector = value ?? (() => DefaultSelector);
 	}
 
 	/// <summary>
@@ -257,4 +258,12 @@ public class ValidatorSelectorOptions {
 		get => _rulesetValidatorSelector;
 		set => _rulesetValidatorSelector = value ?? (ruleSets => new RulesetValidatorSelector(ruleSets));
 	}
+
+	/// <summary>
+	/// Factory func for creating the composite validator selector
+	/// </summary>
+	public Func<IEnumerable<IValidatorSelector>, IValidatorSelector> CompositeValidatorSelectorFactory {
+		get => _compositeValidatorSelectorFactory;
+		set => _compositeValidatorSelectorFactory = value ?? (selectors => new CompositeValidatorSelector(selectors));
+	}
 }