Regex Constraint

RegexConstraint tests that a string matches a regular expression pattern.

Usage

Does.Match(string pattern)
Does.Not.Match(string pattern)

Modifiers

.IgnoreCase

Examples

[Test]
public void RegexConstraint_Examples()
{
    string phrase = "Make your tests fail before passing!";

    Assert.That(phrase, Does.Match("Make.*tests.*pass"));
    Assert.That(phrase, Does.Match("make.*tests.*PASS").IgnoreCase);
    Assert.That(phrase, Does.Not.Match("your.*passing.*tests"));
}

Common Pattern Examples

[Test]
public void RegexConstraint_Pattern_Examples()
{
    // Email validation (simplified)
    Assert.That("user@example.com", Does.Match(@"^[\w.-]+@[\w.-]+\.\w+$"));

    // Phone number format
    Assert.That("555-123-4567", Does.Match(@"^\d{3}-\d{3}-\d{4}$"));

    // Starts with digit
    Assert.That("42 is the answer", Does.Match(@"^\d"));

    // Contains only letters and spaces
    Assert.That("Hello World", Does.Match(@"^[a-zA-Z\s]+$"));

    // ISO date format
    Assert.That("2024-01-15", Does.Match(@"^\d{4}-\d{2}-\d{2}$"));
}

Notes

  1. The pattern uses .NET regular expression syntax.
  2. The entire string does not need to match - use ^ and $ anchors if you need a full match.
  3. For simple substring matching, consider using SubstringConstraint instead.

See Also