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Testing PowerShell Shell Integration Implementation in thefuck

This test suite validates the PowerShell shell integration functionality in the ‘thefuck’ command-line tool. It ensures proper command execution, alias configuration, and version detection across different PowerShell environments.

Test Coverage Overview

The test suite provides comprehensive coverage of PowerShell shell interactions.

Key areas tested include:

Command chaining using the -and operator
Application alias creation and configuration
PowerShell version detection and compatibility
Error handling for version detection failures

Integration points focus on system-level PowerShell execution and version table access.

Implementation Analysis

The testing approach utilizes pytest’s fixture-based architecture for clean test setup and dependency injection. Tests employ mock objects to simulate PowerShell process execution and output handling.

Key patterns include:

Fixture-based test isolation
Parametrized testing for version detection
Mock-based system command execution
Exception handling validation

Technical Details

Testing tools and configuration:

pytest as the primary testing framework
pytest-mock for process simulation
Fixtures for shell instance management
Auto-use fixtures for global test setup
Parametrize decorator for multiple test scenarios
UTF-8 encoding configuration

Best Practices Demonstrated

The test suite demonstrates excellent testing practices through isolation, comprehensive coverage, and clean organization.

Notable practices include:

Proper test isolation using fixtures
Comprehensive mock usage for external dependencies
Explicit test case parameterization
Clear test method naming conventions
Effective use of pytest decorators

nvbn/thefuck

tests/shells/test_powershell.py

            
# -*- coding: utf-8 -*-

import pytest
from thefuck.shells import Powershell


@pytest.mark.usefixtures('isfile', 'no_memoize', 'no_cache')
class TestPowershell(object):
    @pytest.fixture
    def shell(self):
        return Powershell()

    @pytest.fixture(autouse=True)
    def Popen(self, mocker):
        mock = mocker.patch('thefuck.shells.powershell.Popen')
        return mock

    def test_and_(self, shell):
        assert shell.and_('ls', 'cd') == '(ls) -and (cd)'

    def test_app_alias(self, shell):
        assert 'function fuck' in shell.app_alias('fuck')
        assert 'function FUCK' in shell.app_alias('FUCK')
        assert 'thefuck' in shell.app_alias('fuck')

    def test_how_to_configure(self, shell):
        assert not shell.how_to_configure().can_configure_automatically

    @pytest.mark.parametrize('side_effect, expected_version, call_args', [
        ([b'''Major  Minor  Build  Revision
-----  -----  -----  --------
5      1      17763  316     
'''], 'PowerShell 5.1.17763.316', ['powershell.exe']),
        ([IOError, b'PowerShell 6.1.2
'], 'PowerShell 6.1.2', ['powershell.exe', 'pwsh'])])
    def test_info(self, side_effect, expected_version, call_args, shell, Popen):
        Popen.return_value.stdout.read.side_effect = side_effect
        assert shell.info() == expected_version
        assert Popen.call_count == len(call_args)
        assert all([Popen.call_args_list[i][0][0][0] == call_arg for i, call_arg in enumerate(call_args)])

    def test_get_version_error(self, shell, Popen):
        Popen.return_value.stdout.read.side_effect = RuntimeError
        with pytest.raises(RuntimeError):
            shell._get_version()
        assert Popen.call_args[0][0] == ['powershell.exe', '$PSVersionTable.PSVersion']