<PackageReference Include="NUnit" Version="4.2.2" />

RegexConstraint

public class RegexConstraint : Constraint
RegexConstraint can test whether a string matches the pattern provided.
using NUnit.Framework.Internal; using System.Diagnostics.CodeAnalysis; using System.Runtime.CompilerServices; using System.Text.RegularExpressions; namespace NUnit.Framework.Constraints { [System.Runtime.CompilerServices.NullableContext(1)] [System.Runtime.CompilerServices.Nullable(0)] public class RegexConstraint : Constraint { private Regex _regex; public override string Description { get { DefaultInterpolatedStringHandler defaultInterpolatedStringHandler = new DefaultInterpolatedStringHandler(18, 1); defaultInterpolatedStringHandler.AppendLiteral("String matching \""); defaultInterpolatedStringHandler.AppendFormatted(_regex); defaultInterpolatedStringHandler.AppendLiteral("\""); string text = defaultInterpolatedStringHandler.ToStringAndClear(); if ((_regex.Options & RegexOptions.IgnoreCase) == RegexOptions.IgnoreCase) text += ", ignoring case"; return text; } } public RegexConstraint IgnoreCase { get { _regex = new Regex(_regex.ToString(), _regex.Options | RegexOptions.IgnoreCase); return this; } } public RegexConstraint([StringSyntax("Regex")] string pattern) : base(pattern) { _regex = new Regex(pattern); } public RegexConstraint(Regex regex) : base(regex.ToString()) { _regex = regex; } public override ConstraintResult ApplyTo<[System.Runtime.CompilerServices.Nullable(2)] TActual>(TActual actual) { string input = ConstraintUtils.RequireActual<string>(actual, "actual", false); return new ConstraintResult(this, actual, _regex.IsMatch(input)); } } }