epylint runner confounding results of test_relative_beyond... test methods

[jacobtylerwalls]

The tests in TestImportChecker added in #5059 use the epylint pylint runner, not the regular one. epylint patches cwd, so it's not an optimal runner for these tests that are import- and namespace-sensitive.

Indeed, I'm proposing to xfail one test in #7114, but the tests should probably just be removed.

Diff indicating that they don't pass using the regular runner:

diff --git a/tests/checkers/unittest_imports.py b/tests/checkers/unittest_imports.py
index ac36f784f..11f6f19ab 100644
--- a/tests/checkers/unittest_imports.py
+++ b/tests/checkers/unittest_imports.py
@@ -8,10 +8,10 @@ import os
 
 import astroid
 
-from pylint import epylint as lint
 from pylint.checkers import imports
 from pylint.interfaces import UNDEFINED
-from pylint.testutils import CheckerTestCase, MessageTest
+from pylint.lint.run import Run
+from pylint.testutils import CheckerTestCase, MessageTest, GenericTestReporter
 
 REGR_DATA = os.path.join(os.path.dirname(__file__), "..", "regrtest_data", "")
 
@@ -41,38 +41,36 @@ class TestImportsChecker(CheckerTestCase):
 
     @staticmethod
     def test_relative_beyond_top_level_two() -> None:
-        output, errors = lint.py_run(
-            f"{os.path.join(REGR_DATA, 'beyond_top_two')} -d all -e relative-beyond-top-level",
-            return_std=True,
+        run1 = Run(
+            [os.path.join(REGR_DATA, 'beyond_top_two'), "--disable=all -e relative-beyond-top-level"],
+            exit=False,
         )
         top_level_function = os.path.join(
             REGR_DATA, "beyond_top_two/namespace_package/top_level_function.py"
         )
-        output2, errors2 = lint.py_run(
-            f"{top_level_function} -d all -e relative-beyond-top-level",
-            return_std=True,
+        run2 = Run(
+            [top_level_function, "--disable=all -e relative-beyond-top-level"],
+            exit=False,
         )
 
-        assert len(output.readlines()) == len(output2.readlines())
-        assert errors.readlines() == errors2.readlines()
+        assert len(run1.linter.reporter.out.readlines()) == len(run2.linter.reporter.out.readlines())
 
     @staticmethod
     def test_relative_beyond_top_level_three() -> None:
-        output, errors = lint.py_run(
-            f"{os.path.join(REGR_DATA, 'beyond_top_three/a.py')} -d all -e relative-beyond-top-level",
-            return_std=True,
+        run = Run(
+            [os.path.join(REGR_DATA, 'beyond_top_three/a.py'), "--disable=all -e relative-beyond-top-level"],
+            exit=False,
+            reporter=GenericTestReporter()
         )
-        assert len(output.readlines()) == 5
-        assert errors.readlines() == []
+        assert len(run.linter.reporter.out.readlines()) == 5
 
     @staticmethod
     def test_relative_beyond_top_level_four() -> None:
-        output, errors = lint.py_run(
-            f"{os.path.join(REGR_DATA, 'beyond_top_four/module')} -d missing-docstring,unused-import",
-            return_std=True,
+        run = Run(
+            [os.path.join(REGR_DATA, 'beyond_top_four/module'), "--disable=missing-docstring,unused-import"],
+            exit=False,
         )
-        assert len(output.readlines()) == 5
-        assert errors.readlines() == []
+        assert len(run.linter.reporter.out.readlines()) == 5
 
     def test_wildcard_import_init(self) -> None:
         module = astroid.MANAGER.ast_from_module_name("init_wildcard", REGR_DATA)

==================================================== short test summary info =====================================================
FAILED tests/checkers/unittest_imports.py::TestImportsChecker::test_relative_beyond_top_level_three - AssertionError: assert 0 ...
FAILED tests/checkers/unittest_imports.py::TestImportsChecker::test_relative_beyond_top_level_four - assert 0 == 5

The first test also fails in reality but unexpectedly passes because the comparison is to another incorrect result:

$ pylint tests/regrtest_data/beyond_top_two
************* Module beyond_top_two
tests/regrtest_data/beyond_top_two/__init__.py:1:0: F0010: error while code parsing: Unable to load file tests/regrtest_data/beyond_top_two/__init__.py:
[Errno 2] No such file or directory: 'tests/regrtest_data/beyond_top_two/__init__.py' (parse-error)

---

cc/ @DanielNoord

[DanielNoord]

I'll remove these.