Mocking grain client and testability

[AqlaSolutions]

Currently it's not possible to mock generated grain clients because their generated methods are not virtual. For better testability could you consider making them virtual or better additionally generating interfaces for them? For an example, I want to unit test a class which needs to call some grain. Currently I can't test it in isolation because I need to pass an instance of that grain client and that instance can't be mocked.

class SomeClass
{
    private readonly Func<string, MyGrainClient> _grainFactory;
    public SomeClass(Func<string, MyGrainClient> grainFactory) // But MyGrainClient can't be mocked!
    {
        _grainFactory = grainFactory;
    }

    public void SomeMethod(string arg) // I want to test this method without real MyGrainClient
    {
        _grainFactory(arg).MyMethod();
    }
}

[jkpark]

I am facing to mock grain client, Can I ask if you have any solution to mock or fake job?

[rogeralsing]

Currently there are no great ways to do this. However, the code generation is customizable.

e.g. in your project file where you include the ProtoGrain includes:

 <ProtoGrain Include="MyProtoFile.proto" AdditionalImportDirs="." TemplateFiles="MyCustomTemplate.txt" />

This way, it is at least open for modification, you can generate your own extra types, or modify how the grains are generated completely.

The default template can be found here : https://gist.github.com/rogeralsing/4908f8e0063687acfe12c0616b022844

Make a copy of that file, and reference it in the TemplateFiles= part of the ProtoGrain section.