I was hoping not to have to change the interfaces of the application.  Most
of the application is already written and the testing was just an
afterthought :-(

But it might not be that much that need to be changed. I'll give it a shot.

Thanks

On Tue, Nov 8, 2011 at 4:10 PM, Gabriel Scherer
<gabriel.scherer@gmail.com>wrote:

> If you want some module of your system to be parametrized by another
> module (to be able to pass either a concrete module or a mockup
> module), you should use a functor.
>
>  http://caml.inria.fr/pub/docs/manual-ocaml/manual004.html#toc15
>
> in logic.ml
>  module Make (Net_lib : Net_interface) = struct
>    ...
>  end
>
> in main.ml:
>  module Logic = Logic.Make(Net_lib)
>  ..
>
> in main_mockup.ml:
>  module Logic = Logic.Make(Net_mockup)
>  ...
>
> On Tue, Nov 8, 2011 at 4:03 PM, Hans Ole Rafaelsen <hrafaelsen@gmail.com>
> wrote:
> > Hi,
> >
> > I'm trying to create a mockup module to replace a network module when
> doing
> > testing.
> >
> > The application consists of basically 3 parts. Some user interaction.
> This
> > calls some logic of the application, and the logic module might need to
> call
> > some other functions over the network. For testing I want to make a
> mockup
> > of the network module, in addition to synthesize the user interaction. I
> > want to test the logic module. The application has the following files:
> >
> > net_lib.ml:
> > let util_fun a = a
> > let foo a b = a + b
> > let bar a b = a - b
> >
> > logic.ml:
> > let state = ref 0
> > let get_state () = !state
> > let do_op a b =
> >   incr state;
> >   (Net_lib.foo a b) * (Net_lib.bar (Net_lib.util_fun a) b )
> >
> > main_appl.ml:
> > let () =
> >   let a, b  = Scanf.scanf  "%d %d\n" (fun a b -> a,b) in
> >   Printf.printf "Foo %d %d\n%!" (Logic.get_state ()) (Logic.do_op a b)
> >
> > let () =
> >   let a, b  = Scanf.scanf  "%d %d\n" (fun a b -> a,b) in
> >   Printf.printf "Foo %d %d\n%!" (Logic.get_state ()) (Logic.do_op a b)
> >
> >
> > For testing I have the following modules:
> > net_lib_mockup.ml
> > include Net_lib
> > let foo a b = 1
> > let bar a b = 1
> >
> > logic_mockup.ml:
> > module Net_lib = Net_lib_mockup
> > include Logic
> >
> > main_test.ml:
> > module Logic = Logic_mockup
> >
> > let () =
> >   let a, b = (1, 1) in
> >   Printf.printf "Test %d %d\n%!" (Logic.get_state ()) (Logic.do_op a b)
> >
> > let () =
> >   let a, b = (10, 1) in
> >   Printf.printf "Test %d %d\n%!" (Logic.get_state ()) (Logic.do_op a b)
> >
> > The problem is that the "include Logic" has already 'bound' the
> functions in
> > Logic to the Net_lib module and will not use the Net_lib_mockup that I
> try
> > to use through a moudle alias. If i replace the 'include Logic' with the
> > actual content of the logic.ml file, then the functions get bound to the
> > Logic_mockup functions, and the test works as they should.
> >
> > Are there some trick to get the 'include Logic', in logic_mockup.ml, to
> use
> > to the Net_lib_mockup module and not the Net_lib module, so that I don't
> > have to do copy and paste between the two files?
> >
> >
> > Regards,
> >
> > Hans Ole Rafaelsen
> >
> >
>