Changed test naming convention. Added custom fixture for initializing Null object.

apps/cli/executables/null/test/null_test.py → apps/cli/executables/null/test/test_null.py

 import pytest
 import argparse
 
-from null.null import Null
+# from null.null import Null
+from ..src.null.null import Null
 
-parser = argparse.ArgumentParser()
-
-def test_print_error(caplog):
+@pytest.fixture()
+def null():
     null = Null(argparse.Namespace(), True)
+    return null
+
+def test_print_error(null, caplog):
     null.print_error()
     assert 'ERROR: This is an error.' in caplog.text
 
-def test_print_greeting(caplog):
-    null = Null(argparse.Namespace(), True)
+def test_print_greeting(null, caplog):
     null.print_greeting()
     assert 'Hello, world!' in caplog.text
     assert 'And goodbye, world...' in caplog.text
 
-def test_exit_with_failure(caplog):
-    null = Null(argparse.Namespace(), True)
+def test_exit_with_failure(null, caplog):
     with pytest.raises(SystemExit) as e:
         null.exit_with_failure()
         assert 'Error purposefully induced. Exiting with status code -1...' in caplog.text
         assert e.value.code == -1
 
-def test_exit_randomly(caplog):
-    null = Null(argparse.Namespace(), True)
+def test_exit_randomly(null, caplog):
     with pytest.raises(SystemExit) as e:
         null.exit_randomly()
         assert 'Exiting with status code' in caplog.text
         assert -50 <= e.value.code <= 50
 
-def test_take_nap(caplog):
-    null = Null(argparse.Namespace(), True)
+def test_take_nap(null, caplog):
     null.take_nap()
     assert 'Going to sleep...' in caplog.text
     assert 'Waking up.' in caplog.text
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