Some unit tests depend on actually running mvn

[ivanovmg]

These unit tests depend on mvn and actually run it, which makes them not-so-unit-tests.

These tests require mvn executable:

• test/metrics/npath/test_all_types.py::JavaTestCase::testHighScore
• test/metrics/npath/test_all_types.py::JavaTestCase::testIncorrectFormat
• test/metrics/npath/test_all_types.py::JavaTestCase::testLowScore
• test/metrics/npath/test_all_types.py::JavaTestCase::testMediumScore

One may consider using mocking out subprocess for these tests.

There is pytest-subprocess plugin, which allows one to do it quite smoothly.
https://pypi.org/project/pytest-subprocess/
This will require switching to pytest, though.

Related PR: #701

[ivanovmg]

Since #701 has been merged, I can take this task.
First, I am going to refactor module test/metrics/npath/test_all_types.py to use pytest native format.
Then, in another PR I will be able to use pytest-subprocess.

[ivanovmg]

@yegor256 what do you think on this topic?
Maybe this is an intentional behavior that these tests are somewhat integration tests and run mvn process?
They test this module: https://github.com/cqfn/aibolit/blob/master/aibolit/metrics/npath/main.py

[yegor256]

@ivanovmg as I see, the problem is not related to tests, but to the implementation of aibolit/metrics/npath/main.py - it uses mvn in order to calculate metrics. What exactly is the problem? This npath module is slow? Or you don't have mvn installed locally?

[ivanovmg]

@ivanovmg as I see, the problem is not related to tests, but to the implementation of aibolit/metrics/npath/main.py - it uses mvn in order to calculate metrics. What exactly is the problem? This npath module is slow? Or you don't have mvn installed locally?

I did not have mvn installed locally, thus I noticed that these tests invoke mvn. In order to make these tests independent from subprocess it may be a good idea to either change the tests, so that they are not dependent of external processes (mock the subprocess out), or change the actual code of NPathMetric.

As far as I can see now, NPathMetric processes the output file as a result of running mvn pmd:pmd. In this sense, it may be reasonable to change NpathMetric, so that the functionality encapsulated in __parseFile method is tested separately via unit tests.

[yegor256]

@ivanovmg ideally, we should change the implementation of npath/main.py and remove the dependency on Maven. It should not be difficult to implement it in Python.

[ogluvu-ship-it]

@yegor256 please close this issue if its solve