public void Non_nullability_inverts_when_navigation_to_dependent()
{
var dependentEntityTypeBuilder = CreateInternalEntityTypeBuilder <Dependent>();
var principalEntityTypeBuilder =
dependentEntityTypeBuilder.ModelBuilder.Entity(typeof(Principal), ConfigurationSource.Convention);
var relationshipBuilder = dependentEntityTypeBuilder.HasRelationship(
principalEntityTypeBuilder.Metadata,
nameof(Dependent.Principal),
nameof(Principal.Dependent),
ConfigurationSource.Convention);
Assert.Equal(nameof(Dependent), relationshipBuilder.Metadata.DeclaringEntityType.DisplayName());
Assert.False(relationshipBuilder.Metadata.IsRequired);
var navigation = principalEntityTypeBuilder.Metadata.FindNavigation(nameof(Principal.Dependent));
relationshipBuilder = CreateNotNullNavigationConvention().Apply(relationshipBuilder, navigation);
Assert.Equal(nameof(Principal), relationshipBuilder.Metadata.DeclaringEntityType.DisplayName());
Assert.True(relationshipBuilder.Metadata.IsRequired);
var logEntry = ListLoggerFactory.Log.Single();
Assert.Equal(LogLevel.Debug, logEntry.Level);
Assert.Equal(
CoreResources.LogNonNullableOnDependent(new TestLogger <TestLoggingDefinitions>()).GenerateMessage(
nameof(Principal.Dependent), nameof(Principal)), logEntry.Message);
}