public async Task MergePartialTypeMergesModifiers(string firstModifiers, string secondModifiers, InterfaceModifiers expected) { var firstCode = TypeDefinitionCode.EmptyInterface.Replace("interface", firstModifiers + " partial interface"); var secondCode = TypeDefinitionCode.EmptyInterface .Replace("interface", secondModifiers + " partial interface"); var firstNode = await TestNode.FindNode <InterfaceDeclarationSyntax>(firstCode) .ConfigureAwait(false); var secondNode = await TestNode.FindNode <InterfaceDeclarationSyntax>(secondCode) .ConfigureAwait(false); var firstDefinition = new InterfaceDefinition(firstNode); var secondDefinition = new InterfaceDefinition(secondNode); firstDefinition.MergePartialType(secondDefinition); firstDefinition.Modifiers.Should().Be(expected); }