ALL-UNNAMED module does not export all packages from classpath

[Jonathan Gibbons]

Pavel,

It looks like you have tripped over an issue in javac's handling of an 
automatic module, and its ability to read classes from the unnamed 
module (i.e. classpath).

-- Jon


On 03/20/2017 03:19 PM, Pavel Bucek wrote:
> Hi Alex,
>
> The usecase is about compiling tests in maven projects.
>
> I mirrored the content of the zip to github: 
> https://github.com/pavelbucek/reproducer (project contains useful README)
>
> The TestCase.java [1] contains simple testcase, compilable when 
> everything is on the classpath.
>
> When module-info.java is added to the standard sources of a maven 
> module, the compilation changes from "put everything on classpath" to 
> "put test dependencies on classpath, standard dependencies on module 
> path", which results in:
>
> javac -d target/test-classes -classpath 
> lib/junit-4.12.jar:lib/hamcrest-core-1.3.jar:lib/mockito-core-2.7.17.jar:lib/byte-buddy-1.6.11.jar:lib/byte-buddy-agent-1.6.11.jar:lib/objenesis-2.5.jar 
> --module-path target/classes -target 9 -source 9 -Xmodule:tst 
> --add-reads tst=ALL-UNNAMED src/test/java/tst/TestCase.java
>
> Test classes are effectively "patched" into main module (here called 
> "tst") and the module requires "ALL-UNNAMED", to be able to use test 
> dependencies.
>
> I'm not sure about exact cause, but seems like the ALL-UNNAMED module 
> doesn't automatically export all packages, only those which were 
> analyzed as required by some other module.
>
> When TestCase.java doesn't "import 
> org.mockito.stubbing.OngoingStubbing", classpath compilation is ok, 
> since we are not using that type directly. But it is part of the 
> fluent builder pattern, used on line 18 [2]. If there is a mechanism 
> which decides which package is required, it omitted the return type of 
> called "when" method, which caused the error. When the package is 
> explicitly imported, the error is gone and compilation proceeds as 
> expected.
>
> Regards,
> Pavel
>
>
> [1] 
> https://github.com/pavelbucek/reproducer/blob/master/src/test/java/tst/TestCase.java
> [2] 
> https://github.com/pavelbucek/reproducer/blob/master/src/test/java/tst/TestCase.java#L18
>
>
> On 20/03/2017 22:56, Alex Buckley wrote:
>> I can't figure out which classes are on which path, and why you think 
>> ALL-UNNAMED should export FROM the classpath when its purpose is to 
>> export TO the classpath.
>>
>> Please clarify your configuration in a few short sentences, rather 
>> than asking us to open a zip file on an unknown host.
>>
>> Alex
>>
>> On 3/20/2017 2:44 PM, Pavel Bucek wrote:
>>> // moving from jdk9-dev, as suggested.
>>>
>>> Hi Jon,
>>>
>>> Thanks for clarification of the error message.
>>>
>>> The main point here is that adding "import ... " fixes the issue, which
>>> doesn't feel correct.
>>>
>>> When dependencies are put on the classpath, the import statement is not
>>> required.
>>>
>>> Regards,
>>> Pavel
>>>
>>> On 20/03/2017 22:26, Jonathan Gibbons wrote:
>>>> If nothing else, the javac error message needs work.
>>>>
>>>>> (package org.mockito.stubbing is declared in module , which does not
>>>>> export it)
>>>>
>>>> The space between "module" and "," means there's an "empty" module
>>>> name there, for the unnamed module, which should have been stated
>>>> explicitly (i.e. "declared in the unnamed module").
>>>>
>>>> Follow-ups would be better on jigsaw-dev or compiler-dev.
>>>>
>>>> -- Jon
>>>>
>>>>
>>>>
>>>> On 03/20/2017 02:15 PM, Libor Kramolis wrote:
>>>>> Hello.
>>>>>
>>>>> I have problem to compile following unit test:
>>>>> import org.junit.Test;
>>>>> import static org.junit.Assert.assertEquals;
>>>>> import static org.mockito.ArgumentMatchers.any;
>>>>> import static org.mockito.Mockito.mock;
>>>>> import static org.mockito.Mockito.when;
>>>>>
>>>>> public class TestCase {
>>>>>
>>>>>      @Test
>>>>>      public void test() {
>>>>>          Context context = mock(Context.class);
>>>>>          when(context.test(any())) //returns
>>>>> org.mockito.stubbing.OngoingStubbing
>>>>>                  .thenReturn("mock");
>>>>>
>>>>>          assertEquals("mock", context.test("any"));
>>>>>      }
>>>>>
>>>>>      interface Context {
>>>>>          String test(String value);
>>>>>      }
>>>>>
>>>>> }
>>>>> with following error:
>>>>>
>>>>> src/test/java/tst/TestCase.java:15: error:
>>>>> OngoingStubbing.thenReturn(T,T...) in package org.mockito.stubbing is
>>>>> not accessible
>>>>>                  .thenReturn("mock");
>>>>>                  ^
>>>>>    (package org.mockito.stubbing is declared in module , which does
>>>>> not export it)
>>>>>    where T is a type-variable:
>>>>>      T extends Object declared in interface OngoingStubbing
>>>>> 1 error
>>>>>
>>>>> Interface org.mockito.stubbing.OngoingStubbing is returned by when(…)
>>>>> method. And whenever I explicitly import the interface (no other
>>>>> change in code is necessary) compilation works.
>>>>>
>>>>> Full reproduced sources are available in zip file at
>>>>> http://anise.cz/~paja/liba/reproducer.zip
>>>>> <http://anise.cz/~paja/liba/reproducer.zip>. It contains javac
>>>>> commands. It is also possible to build it by Maven.
>>>>>
>>>>> What do you think about this behaviour? It seems to me as a bug. The
>>>>> import statement is very artificial in this case.
>>>>>
>>>>> Thanks in advance for your help.
>>>>>
>>>>> Best regards,
>>>>> Libor
>>>>
>>>
>