StartsWith Constraint

StartsWithConstraint tests for an initial string.

Constructor

csharp

StartsWithConstraint(string expected)

Syntax

csharp

Does.StartWith(string expected)
StartsWith(string expected)

Modifiers

csharp

...IgnoreCase
...Using(StringComparison comparisonType)
...Using(CultureInfo culture)

Examples of Use

csharp

string phrase = "Make your tests fail before passing!";

Assert.That(phrase, Does.StartWith("Make"));
Assert.That(phrase, Does.Not.StartWith("Break"));

Specifying a StringComparison

csharp

Assert.That("Hello World!", Does.StartWith("HELLO").Using(StringComparison.OrdinalIgnoreCase));
Assert.That("Hello World!", Does.StartWith("Hello").Using(StringComparison.Ordinal));

Specifying a CultureInfo

The Using(CultureInfo) modifier allows for culture-specific string comparisons. It can be combined with .IgnoreCase for case-insensitive culture-aware comparisons:

csharp

// Using Turkish culture where 'i' and 'I' have special casing rules
Assert.That("TITLE text", Does.StartWith("title").IgnoreCase.Using(new CultureInfo("tr-TR")));

// Culture-specific comparison without case-insensitivity
Assert.That("Straße Street", Does.StartWith("Straße").Using(new CultureInfo("de-DE")));

Notes

StartsWith may appear only in the body of a constraint expression or when the inherited syntax is used.
Only one Using modifier may be specified. Attempting to use multiple Using modifiers will throw an InvalidOperationException.