How to compile test code in a modular project?

[Till Brychcy]

> Am 09.11.2017 um 09:29 schrieb Alan Bateman <Alan.Bateman at oracle.com>:
> 
> Yes, --patch-module is needed to compile the tests "as if" they are part of the module, e.g.
> 
>   javac --module-path classes:junit.jar --patch-module m=src/test/java --add-reads m=junit -d test-classes \
>       src/test/java/p1/P1Test.java
> 

Thanks a lot, Alan! 

The surprise for me was that --patch-module is used for source folders, too. I thought it was only for binaries.

But I noted I also have to add "--add-modules=junit" or the "--add-reads m=junit" will give an error that module junit cannot be found. 
So the command has to be:
   javac -d target/test-classes --patch-module m=src/test/java --module-path target/classes:junit-4.8.2.jar --add-modules=junit --add-reads m=junit src/test/java/p1/P1Test.java

I’m not sure if that is a bug or a feature.  BTW, I noted that "javac -help" doesn’t mention --patch-module and --add-reads at all (only --add-modules)