Actually, you can. The default configuration factory is exposed by the static
property EquivalencyAssertionOptions<Test>.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<Test>.Default;
EquivalencyAssertionOptions<Test>.Default = () =>
{
var config = defaultAssertionOptions();
config.Using<DateTime>(ctx => ctx.Subject.Should().BeCloseTo(ctx.Expectation)).WhenTypeIs<DateTime>();
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.