Added support for getting a list of files from a jar directory in ResourceOf.

[PeJetuz]

Added support for getting file names when reading a directory from a jar.
Added a test for getting file names when reading a directory.
Added 'test-data' module that builds a test jar file.

[PeJetuz]

@yegor256 Will you please review?

[yegor256]

@PeJetuz thanks for the contribution! I'm not sure the location of the test-data/ directory is correct. I believe, all test resources and data must stay inside src/test/ directory, by convention in Maven.

[PeJetuz]

@yegor256 Thanks! I don't like test-data/ either. I thought maybe someone would like the original project to build test-data-0.0.1.jar. Since it only contains 3 text files, it should be easy to recreate.

[yegor256]

@PeJetuz indeed, it's good to have sources in Git repo, instead of a binary .jar. But we should keep files in the src/test/, not in the root.

[PeJetuz]

@yegor256 Now test-data-0.0.1.jar is in src/test/resources/. For testing, we need to have a separate jar file in the classpath. Then in tests we can get a list of files from this jar. Or I don't understand something, please explain.

[yegor256]

@PeJetuz "force push" is a bad idea in general, because it's confusing for the reviewer (just FYI)

[yegor256]

@PeJetuz it's not a good idea to keep binary files inside Git repository. Better generate/build this JAR in compile time, and place into target/. You can use maven-assembly-plugin for that and some test data from src/test/.

[PeJetuz]

@yegor256 I thought it was important to you that the intermediate results were not included in the final commit. Thank you, I will fix it!

[PeJetuz]

@yegor256 Done. Thanks!

[yegor256]

@PeJetuz why not this formatting instead?

return new InputStreamOf(
  names
    .stream()
    .collect(Collectors.joining("\n"))
    .getBytes(StandardCharsets.UTF_8)
);

[PeJetuz]

@yegor256 Done.

[yegor256]

@PeJetuz read this, please: https://www.yegor256.com/2015/01/21/if-then-throw-else.html

[PeJetuz]

@yegor256 Thanks for the article. I replaced while/if/else with stream.

[yegor256]

@PeJetuz looks much better now, but I still suggest placing it into src/test/ instead of src/test/resources/. All files from src/test/resources/ are automatically moved to target/test-classes/. I believe, this is not your plan for these files.

[PeJetuz]

@yegor256 I changed the location of test-lib to src/test. I replaced while/if/else with stream and fixed the formatting.
Sorry, I didn't know force-push breaks changelog.
Thanks for your help!

[PeJetuz]

@yegor256 Hi! Is there anything else that needs to be improved?