C# Fluent Assertions global options for ShouldBeEquivalentTo

Question

In Fluent Assertions when comparing objects with DateTime properties there are sometimes a slight mismatch in the milliseconds and the comparison fail. The way we get around it

Answer 1

Actually, you can. The default configuration factory is exposed by the static property EquivalencyAssertionOptions.Default. You can easily assign an alternative configuration for a particular data type, or extend the default configuration with additional behavior. Something like:

var defaultAssertionOptions = EquivalencyAssertionOptions.Default;

EquivalencyAssertionOptions.Default = () =>
{
    var config = defaultAssertionOptions();
    config.Using(ctx => ctx.Subject.Should().BeCloseTo(ctx.Expectation)).WhenTypeIs();
    return config;
};

If you want you can get the current default and tuck that away in some variable that you use from your factory method.