modulepath and classpath mixture

[Russell Gold]

> On Mar 23, 2016, at 3:21 AM, Alan Bateman <Alan.Bateman at oracle.com> wrote:
> 
> On 22/03/2016 22:20, Russell Gold wrote:
>> I’d like to take a step back here. It may be that I have completely misunderstood what is going on, but this all seems to have gotten way more complicated than it should.
>> 
>> I am assuming:
>> 
>> 1) the project has both module and class path compile dependencies, and possibly has both module and class path test dependencies as well.
>> 2) the artifact type “module” (or something similar) is now recognized as indicating a Jigsaw module (which needs to go on the module path)
>> 3) the classes being built may be put into their own module, but might not be.
>> 
>> Then there are really four categories of dependencies. The compile step needs to place its jar dependencies on the class path and its module dependencies on the module path. I presume that is what Robert is already doing.
>> The test-compile step needs to handle all four, including the compiled class in its test class path.
>> 
>> Then there is no need to compile either the main or test classes as part of a module. They may use modules, but that is a different matter. No need for the -Xmodule switch at all. The only reference to module is as dependencies.
>> 
>> Did I completely miss the point?
>> 
> It depends on where the tests live. If they are black box tests that only exercise the API (the public types in the module's exported packages) then they can live anywhere. If they are in the same class loader and package as the code they are testing (the norm in Maven) then they need to compiled as if they are part of the module. We might think of these as white box tests as they can make use of public types in packages that aren't exported, maybe they are using package-private types/methods too.
> 

Why does the module concept even need to exist at that point? Seems to me that it is much simpler to treat them as classes on the class path rather than a module. The module status can come in during packaging, no?

- Russ