Usecase as step

[jhomarolo]

Is your feature request related to a problem? Please describe.
Today, it is very common to nest usecases to resolve a complete application flow.

When we call one usecase inside another, we end up calling it as a method and not natively as a usecase step.

This functionality will help to have a cleaner code, more metadata about the use of nested use cases, in addition to opening up possibilities to have an even richer audit trail

[dalssoft]

Suggested code:

    'Save the User': usecaseStep(saveUser, {
        
        user: (ctx) => ctx.user,  // optional, with the default value of ctx.user
        
        request: (ctx) => ({
            // optional, with the default values comming from the context
            // - read all the request metadata from the use case
            // - try to find the expected fields in the context
            // or, in case of a custom request, you can define the request as below
            name: ctx..name1,
            email: ctx.email2,
            password: ctx.password3,
        }),

        response: (ret) => ({
            // optional, with the default value of ret
            // once the use case is executed, the response is returned
            // and merged with the context
            // for example, the user id can be returned and used in the next step
            userId: ret.id,
            // this is the same as:
            // ctx.saveUser.userId = ret.id
            // I think it is important to have a isolation variable with the name of the use case (saveUser)
        }),
    }),

I'm still not sure if the function name usecaseStep is the best name, but I think it is a good start.

[jhomarolo]

I believe that a use case can be passed as a variable, so I agree with your sugestion

And also a basic validation to check if that ucStep is in fact a valid usecase.