Enabled ruff PT ruleset for pytest best practices

Author: tleonhardt

plugins/ext_test/cmd2_ext_test/cmd2_ext_test.py

@@ -39,7 +39,8 @@ def app_cmd(self, command: str, echo: Optional[bool] = None) -> cmd2.CommandResu
         :param echo: Flag whether the command's output should be echoed to stdout/stderr
         :return: A CommandResult object that captures stdout, stderr, and the command's result object
         """
-        assert isinstance(self, cmd2.Cmd) and isinstance(self, ExternalTestMixin)
+        assert isinstance(self, cmd2.Cmd)
+        assert isinstance(self, ExternalTestMixin)
         try:
             self._in_py = True
 

pyproject.toml

@@ -199,7 +199,7 @@ select = [
     "PLE",  # Pylint Errors
     # "PLR", # Pylint Refactoring suggestions
     "PLW", # Pylint Warnings
-    # "PT",  # flake8-pytest-style (warnings about unit test best practices)
+    "PT",  # flake8-pytest-style (warnings about unit test best practices)
     # "PTH",  # flake8-use-pathlib (force use of pathlib instead of os.path)
     "PYI", # flake8-pyi (warnings related to type hint best practices)
     # "Q",    # flake8-quotes (force double quotes)

tests/test_cmd2.py

@@ -622,15 +622,16 @@ def test_passthrough_exception_in_command(base_app):
     """Test raising a PassThroughException in a command"""
     import types
 
+    expected_err = "Pass me up"
+
     def do_passthrough(self, _):
-        wrapped_ex = OSError("Pass me up")
+        wrapped_ex = OSError(expected_err)
         raise exceptions.PassThroughException(wrapped_ex=wrapped_ex)
 
     setattr(base_app, 'do_passthrough', types.MethodType(do_passthrough, base_app))
 
-    with pytest.raises(OSError) as excinfo:
+    with pytest.raises(OSError, match=expected_err):
         base_app.onecmd_plus_hooks('passthrough')
-    assert 'Pass me up' in str(excinfo.value)
 
 
 def test_output_redirection(base_app):
@@ -1033,7 +1034,7 @@ def test_cmdloop_without_rawinput():
 
     expected = app.intro + '\n'
 
-    with pytest.raises(OSError):
+    with pytest.raises(OSError):  # noqa: PT011
         app.cmdloop()
     out = app.stdout.getvalue()
     assert out == expected
@@ -1794,11 +1795,11 @@ def test_commandresult_falsy(commandresult_app):
 
 def test_is_text_file_bad_input(base_app):
     # Test with a non-existent file
-    with pytest.raises(OSError):
+    with pytest.raises(FileNotFoundError):
         utils.is_text_file('does_not_exist.txt')
 
     # Test with a directory
-    with pytest.raises(OSError):
+    with pytest.raises(IsADirectoryError):
         utils.is_text_file('.')
 
 

tests/test_history.py

@@ -225,8 +225,9 @@ def test_history_class_span(hist):
     assert span[3].statement.raw == 'third'
 
     value_errors = ['fred', 'fred:joe', '2', '-2', 'a..b', '2 ..', '1 : 3', '1:0', '0:3']
+    expected_err = "History indices must be positive or negative integers, and may not be zero."
     for tryit in value_errors:
-        with pytest.raises(ValueError):
+        with pytest.raises(ValueError, match=expected_err):
             hist.span(tryit)
 
 
@@ -275,8 +276,9 @@ def test_persisted_history_span(persisted_hist):
     assert span[5].statement.raw == 'fifth'
 
     value_errors = ['fred', 'fred:joe', '2', '-2', 'a..b', '2 ..', '1 : 3', '1:0', '0:3']
+    expected_err = "History indices must be positive or negative integers, and may not be zero."
     for tryit in value_errors:
-        with pytest.raises(ValueError):
+        with pytest.raises(ValueError, match=expected_err):
             persisted_hist.span(tryit)
 
 
@@ -358,7 +360,8 @@ def test_history_from_json(hist):
     invalid_ver_json = hist.to_json()
     History._history_version = backed_up_ver
 
-    with pytest.raises(ValueError):
+    expected_err = "Unsupported history file version: BAD_VERSION. This application uses version 1.0.0."
+    with pytest.raises(ValueError, match=expected_err):
         hist.from_json(invalid_ver_json)
 
 
@@ -652,7 +655,8 @@ def test_history_with_span_index_error(base_app):
     run_cmd(base_app, 'help')
     run_cmd(base_app, 'help history')
     run_cmd(base_app, '!ls -hal :')
-    with pytest.raises(ValueError):
+    expected_err = "History indices must be positive or negative integers, and may not be zero."
+    with pytest.raises(ValueError, match=expected_err):
         base_app.onecmd('history "hal :"')
 
 

tests/test_plugin.py

@@ -949,9 +949,9 @@ def test_cmdfinalization_hook_passthrough_exception():
     app = PluggedApp()
     app.register_cmdfinalization_hook(app.cmdfinalization_hook_passthrough_exception)
 
-    with pytest.raises(OSError) as excinfo:
+    expected_err = "Pass me up"
+    with pytest.raises(OSError, match=expected_err):
         app.onecmd_plus_hooks('say hello')
-    assert 'Pass me up' in str(excinfo.value)
     assert app.called_cmdfinalization == 1
 
 

tests/test_table_creator.py

@@ -27,18 +27,16 @@
 
 def test_column_creation():
     # Width less than 1
-    with pytest.raises(ValueError) as excinfo:
+    with pytest.raises(ValueError, match="Column width cannot be less than 1"):
         Column("Column 1", width=0)
-    assert "Column width cannot be less than 1" in str(excinfo.value)
 
     # Width specified
     c = Column("header", width=20)
     assert c.width == 20
 
     # max_data_lines less than 1
-    with pytest.raises(ValueError) as excinfo:
+    with pytest.raises(ValueError, match="Max data lines cannot be less than 1"):
         Column("Column 1", max_data_lines=0)
-    assert "Max data lines cannot be less than 1" in str(excinfo.value)
 
     # No width specified, blank label
     c = Column("")
@@ -311,15 +309,13 @@ def test_generate_row_exceptions():
     # Unprintable characters
     for arg in ['fill_char', 'pre_line', 'inter_cell', 'post_line']:
         kwargs = {arg: '\n'}
-        with pytest.raises(ValueError) as excinfo:
+        with pytest.raises(ValueError, match=f"{arg} contains an unprintable character"):
             tc.generate_row(row_data=row_data, is_header=False, **kwargs)
-        assert "{} contains an unprintable character".format(arg) in str(excinfo.value)
 
     # Data with too many columns
     row_data = ['Data 1', 'Extra Column']
-    with pytest.raises(ValueError) as excinfo:
+    with pytest.raises(ValueError, match="Length of row_data must match length of cols"):
         tc.generate_row(row_data=row_data, is_header=False)
-    assert "Length of row_data must match length of cols" in str(excinfo.value)
 
 
 def test_tabs():
@@ -332,9 +328,8 @@ def test_tabs():
     row = tc.generate_row(row_data, is_header=True, fill_char='\t', pre_line='\t', inter_cell='\t', post_line='\t')
     assert row == '  Col  1                Col 2  '
 
-    with pytest.raises(ValueError) as excinfo:
+    with pytest.raises(ValueError, match="Tab width cannot be less than 1" ):
         TableCreator([column_1, column_2], tab_width=0)
-    assert "Tab width cannot be less than 1" in str(excinfo.value)
 
 
 def test_simple_table_creation():
@@ -439,24 +434,20 @@ def test_simple_table_creation():
     )
 
     # Invalid column spacing
-    with pytest.raises(ValueError) as excinfo:
+    with pytest.raises(ValueError, match="Column spacing cannot be less than 0"):
         SimpleTable([column_1, column_2], column_spacing=-1)
-    assert "Column spacing cannot be less than 0" in str(excinfo.value)
 
     # Invalid divider character
-    with pytest.raises(TypeError) as excinfo:
+    with pytest.raises(TypeError, match="Divider character must be exactly one character long"):
         SimpleTable([column_1, column_2], divider_char='too long')
-    assert "Divider character must be exactly one character long" in str(excinfo.value)
 
-    with pytest.raises(ValueError) as excinfo:
+    with pytest.raises(ValueError, match="Divider character is an unprintable character"):
         SimpleTable([column_1, column_2], divider_char='\n')
-    assert "Divider character is an unprintable character" in str(excinfo.value)
 
     # Invalid row spacing
     st = SimpleTable([column_1, column_2])
-    with pytest.raises(ValueError) as excinfo:
+    with pytest.raises(ValueError, match="Row spacing cannot be less than 0"):
         st.generate_table(row_data, row_spacing=-1)
-    assert "Row spacing cannot be less than 0" in str(excinfo.value)
 
     # Test header and data colors
     st = SimpleTable([column_1, column_2], divider_char=None, header_bg=Bg.GREEN, data_bg=Bg.LIGHT_BLUE)
@@ -487,9 +478,8 @@ def test_simple_table_width():
         assert SimpleTable.base_width(num_cols) == (num_cols - 1) * 2
 
     # Invalid num_cols value
-    with pytest.raises(ValueError) as excinfo:
+    with pytest.raises(ValueError, match="Column count cannot be less than 1"):
         SimpleTable.base_width(0)
-    assert "Column count cannot be less than 1" in str(excinfo.value)
 
     # Total width
     column_1 = Column("Col 1", width=16)
@@ -509,9 +499,8 @@ def test_simple_generate_data_row_exceptions():
 
     # Data with too many columns
     row_data = ['Data 1', 'Extra Column']
-    with pytest.raises(ValueError) as excinfo:
+    with pytest.raises(ValueError, match="Length of row_data must match length of cols"):
         tc.generate_data_row(row_data=row_data)
-    assert "Length of row_data must match length of cols" in str(excinfo.value)
 
 
 def test_bordered_table_creation():
@@ -573,9 +562,8 @@ def test_bordered_table_creation():
     )
 
     # Invalid padding
-    with pytest.raises(ValueError) as excinfo:
+    with pytest.raises(ValueError, match="Padding cannot be less than 0"):
         BorderedTable([column_1, column_2], padding=-1)
-    assert "Padding cannot be less than 0" in str(excinfo.value)
 
     # Test border, header, and data colors
     bt = BorderedTable([column_1, column_2], border_fg=Fg.LIGHT_YELLOW, border_bg=Bg.WHITE,
@@ -629,9 +617,8 @@ def test_bordered_table_width():
     assert BorderedTable.base_width(3, padding=3) == 22
 
     # Invalid num_cols value
-    with pytest.raises(ValueError) as excinfo:
+    with pytest.raises(ValueError, match="Column count cannot be less than 1"):
         BorderedTable.base_width(0)
-    assert "Column count cannot be less than 1" in str(excinfo.value)
 
     # Total width
     column_1 = Column("Col 1", width=15)
@@ -651,9 +638,8 @@ def test_bordered_generate_data_row_exceptions():
 
     # Data with too many columns
     row_data = ['Data 1', 'Extra Column']
-    with pytest.raises(ValueError) as excinfo:
+    with pytest.raises(ValueError, match="Length of row_data must match length of cols"):
         tc.generate_data_row(row_data=row_data)
-    assert "Length of row_data must match length of cols" in str(excinfo.value)
 
 
 def test_alternating_table_creation():
@@ -711,9 +697,8 @@ def test_alternating_table_creation():
     )
 
     # Invalid padding
-    with pytest.raises(ValueError) as excinfo:
+    with pytest.raises(ValueError, match="Padding cannot be less than 0"):
         AlternatingTable([column_1, column_2], padding=-1)
-    assert "Padding cannot be less than 0" in str(excinfo.value)
 
     # Test border, header, and data colors
     at = AlternatingTable([column_1, column_2], border_fg=Fg.LIGHT_YELLOW, border_bg=Bg.WHITE,

tests/test_utils.py

@@ -329,7 +329,7 @@ def test_context_flag_bool(context_flag):
 
 
 def test_context_flag_exit_err(context_flag):
-    with pytest.raises(ValueError):
+    with pytest.raises(ValueError, match="count has gone below 0"):
         context_flag.__exit__()
 
 
@@ -423,14 +423,14 @@ def test_truncate_line_already_fits():
 def test_truncate_line_with_newline():
     line = 'fo\no'
     max_width = 2
-    with pytest.raises(ValueError):
+    with pytest.raises(ValueError, match="text contains an unprintable character"):
         cu.truncate_line(line, max_width)
 
 
 def test_truncate_line_width_is_too_small():
     line = 'foo'
     max_width = 0
-    with pytest.raises(ValueError):
+    with pytest.raises(ValueError, match="max_width must be at least 1"):
         cu.truncate_line(line, max_width)
 
 
@@ -548,7 +548,7 @@ def test_align_text_width_is_too_small():
     text = 'foo'
     fill_char = '-'
     width = 0
-    with pytest.raises(ValueError):
+    with pytest.raises(ValueError, match="width must be at least 1"):
         cu.align_text(text, cu.TextAlignment.LEFT, fill_char=fill_char, width=width)
 
 
@@ -564,7 +564,7 @@ def test_align_text_fill_char_is_newline():
     text = 'foo'
     fill_char = '\n'
     width = 5
-    with pytest.raises(ValueError):
+    with pytest.raises(ValueError, match="Fill character is an unprintable character"):
         cu.align_text(text, cu.TextAlignment.LEFT, fill_char=fill_char, width=width)
 
 
@@ -613,7 +613,7 @@ def test_align_text_has_unprintable():
     text = 'foo\x02'
     fill_char = '-'
     width = 5
-    with pytest.raises(ValueError):
+    with pytest.raises(ValueError, match="Text to align contains an unprintable character"):
         cu.align_text(text, cu.TextAlignment.LEFT, fill_char=fill_char, width=width)
 
 
@@ -830,7 +830,7 @@ def test_to_bool_str_false():
 
 
 def test_to_bool_str_invalid():
-    with pytest.raises(ValueError):
+    with pytest.raises(ValueError):  # noqa: PT011
         cu.to_bool('other')
 
 

tests_isolated/test_commandset/conftest.py

@@ -15,12 +15,10 @@
     mock,
 )
 
+import pytest
 from cmd2_ext_test import (
     ExternalTestMixin,
 )
-from pytest import (
-    fixture,
-)
 
 import cmd2
 from cmd2.rl_utils import (
@@ -134,7 +132,7 @@ def run_cmd(app, cmd):
     return normalize(out), normalize(err)
 
 
-@fixture
+@pytest.fixture
 def base_app():
     return cmd2.Cmd()
 
@@ -183,13 +181,13 @@ def __init__(self, *args, **kwargs):
         super(WithCommandSets, self).__init__(*args, **kwargs)
 
 
-@fixture
+@pytest.fixture
 def command_sets_app():
     app = WithCommandSets()
     return app
 
 
-@fixture
+@pytest.fixture
 def command_sets_manual():
     app = WithCommandSets(auto_load_commands=False)
     return app

tests_isolated/test_commandset/test_commandset.py

@@ -1149,7 +1149,10 @@ def __init__(self):
     cmdset_nopfx = WithSettablesNoPrefix()
     app.register_command_set(cmdset_nopfx)
 
-    with pytest.raises(ValueError):
+    with pytest.raises(
+        ValueError,
+        match="Cannot force settable prefixes. CommandSet WithSettablesNoPrefix does not have a settable prefix defined.",
+    ):
         app.always_prefix_settables = True
 
     app.unregister_command_set(cmdset_nopfx)