Testing, shims and package private classes

[Kevin Rushforth]

inline

On 12/13/2022 12:55 AM, John Hendrikx wrote:
> Hi all,
>
> I was wondering, is there a reason for the current test setup in the 
> JavaFX code base?
>
> Currently, tests are all stored under src/test/java under a special 
> package name prefixed with "test". This is an (IMHO) unusual practice 
> as normally tests mirror the same packages as their main classes to 
> aid in testability. Testing a package private class is really hard 
> because of this and requires the use of a shim -- the shims do mirror 
> the same package hierarchy as the main classes.

Yes, this was a deliberate decision. We intentionally moved all tests 
out of the javafx.* hierarchy, primarily so that they could run in the 
unnamed module as part of the JDK 9 modularization and encapsulation 
effort, and added the shims to support whitebox testing. See 
https://bugs.openjdk.org/browse/JDK-8134760

> A few questions related to this:
>
> 1) When testing a package private class in the com.sun.* hierarchy, is 
> it okay to just make the class public (as it is already private API) 
> so it can be tested without a shim?

In general, yes. If you need to do whitebox testing of a com.sun class, 
there is no need to use a shim (although I see that was done in a small 
number of cases).

> 2) Can at least the com.sun.* hierarchy be mirrored in src/test/java 
> without the "test" package prefix?  Again, they're both non-public 
> packages anyway.

No, that would require running those tests in the javafx.* module and is 
not the direction I would want to go.

>
> 3) Can we perhaps move all test classes to the package of their main 
> counterparts, and do away with (probably all) shims?

No.

-- Kevin

>
> --John
>