<PackageReference Include="NUnit" Version="3.7.0" />

AllItemsConstraint

AllItemsConstraint applies another constraint to each item in a collection, succeeding if they all succeed.
using System; using System.Collections; namespace NUnit.Framework.Constraints { public class AllItemsConstraint : PrefixConstraint { public override string DisplayName => "All"; public AllItemsConstraint(IConstraint itemConstraint) : base(itemConstraint) { base.DescriptionPrefix = "all items"; } public override ConstraintResult ApplyTo<TActual>(TActual actual) { if (!(((object)actual) is IEnumerable)) throw new ArgumentException("The actual value must be an IEnumerable", "actual"); foreach (object item in (IEnumerable)(object)actual) { if (!base.BaseConstraint.ApplyTo(item).IsSuccess) return new ConstraintResult(this, actual, ConstraintStatus.Failure); } return new ConstraintResult(this, actual, ConstraintStatus.Success); } } }