Fix assertions Without*** when there are multiple failures (#1937)

src/FluentValidation.Tests/ValidatorTesterTester.cs

@@ -469,6 +469,22 @@ public class ValidatorTesterTester {
 				ex.Message.ShouldEqual("Found an unexpected error code of 'bar'");
 		}
 
+		[Fact]
+		public void Unexpected_without_error_code_check() {
+			//#1937
+			var validator = new InlineValidator<Person> {
+				v => v.RuleFor(x => x.Surname).NotNull(),
+				v => v.RuleFor(x => x.Forename).NotNull()
+			};
+
+			validator.TestValidate(new Person())
+				.ShouldHaveValidationErrorFor(x => x.Surname)
+				.WithoutErrorCode("foo")
+				.WithoutErrorMessage("bar")
+				.WithoutSeverity(Severity.Warning)
+				.WithoutCustomState(1);
+		}
+
 		[Fact]
 		public void Expected_severity_check() {
 			var validator = new InlineValidator<Person> {

src/FluentValidation/TestHelper/ITestValidationContinuation.cs

@@ -9,6 +9,7 @@ public interface ITestValidationWith : ITestValidationContinuation {
 	}
 
 	public interface ITestValidationContinuation : IEnumerable<ValidationFailure> {
+		IEnumerable<ValidationFailure> MatchedFailures { get; }
 		IEnumerable<ValidationFailure> UnmatchedFailures { get; }
 	}
 

src/FluentValidation/TestHelper/ValidatorTestExtensions.cs

@@ -198,7 +198,7 @@ public static class ValidationTestExtension {
 		}
 
 		public static ITestValidationContinuation WhenAll(this ITestValidationContinuation failures, Func<ValidationFailure, bool> failurePredicate, string exceptionMessage = null) {
-			var result = TestValidationContinuation.Create(failures);
+			var result = TestValidationContinuation.Create(failures.MatchedFailures);
 			result.ApplyPredicate(failurePredicate);
 
 			bool allMatched = !result.UnmatchedFailures.Any();