Build: PyLint unit test skipped if not installed except on TravisCI

CHANGES

@@ -1,6 +1,7 @@
 Back In Time
 
 Version 1.4.4-dev (development of upcoming release)
+* Build: PyLint unit test is skipped if PyLint isn't installed except TravisCI will raise an error (#1634)
 * Build: Fix bash-completion symlink creation while installing & adding --diagnostics (#1615)
 * Build: Activate PyLint error E602 (undefined-variable)
 * Build: TravisCI use PyQt (except arch "ppc64le")

common/test/test_lint.py

@@ -1,8 +1,15 @@
 import unittest
+import os
 import pathlib
 import subprocess
+import shutil
 from typing import Iterable
 
+ON_TRAVIS = os.environ.get('TRAVIS', '') == 'true'
+PYLINT_AVIALBE = not shutil.which('pylint') is None
+PYLINT_REASON = ('Using PyLint is mandatory on TravisCI and otherwise '
+                 'optional to systems where PyLint is available.')
+
 
 class MirrorMirrorOnTheWall(unittest.TestCase):
     """Check all py-files in the package (incl. test files) for lints and
@@ -32,6 +39,7 @@ def _collect_py_files(self) -> Iterable[pathlib.Path]:
         # Find recursive all py-files.
         return path.rglob('**/*.py')
 
+    @unittest.skipUnless(ON_TRAVIS or PYLINT_AVIALBE, PYLINT_REASON)
     def test_with_pylint(self):
         """Use Pylint to check for specific error codes.
 

qt/test/test_lint.py

@@ -1,8 +1,15 @@
 import unittest
+import os
 import pathlib
 import subprocess
+import shutil
 from typing import Iterable
 
+ON_TRAVIS = os.environ.get('TRAVIS', '') == 'true'
+PYLINT_AVIALBE = not shutil.which('pylint') is None
+PYLINT_REASON = ('Using PyLint is mandatory on TravisCI and otherwise '
+                 'optional to systems where PyLint is available.')
+
 
 class MirrorMirrorOnTheWall(unittest.TestCase):
     """Check all py-files in the package (incl. test files) for lints and
@@ -32,6 +39,7 @@ def _collect_py_files(self) -> Iterable[pathlib.Path]:
         # Find recursive all py-files.
         return path.rglob('**/*.py')
 
+    @unittest.skipUnless(ON_TRAVIS or PYLINT_AVIALBE, PYLINT_REASON)
     def test_with_pylint(self):
         """Use Pylint to check for specific error codes.