Back to Repositories

Testing SSH Known Hosts Verification in thefuck

This test suite validates the SSH known hosts functionality in thefuck, focusing on handling host key verification failures and automated key management. It ensures proper handling of SSH connection errors and host key changes through comprehensive unit tests.

Test Coverage Overview

The test suite provides thorough coverage of SSH known hosts functionality.

Key areas tested include:

Host key verification failure scenarios
Command matching for SSH and SCP operations
Handling of changed remote host identifications
File system operations for known_hosts modifications

Integration points cover command parsing, file system interactions, and error message handling.

Implementation Analysis

The testing approach uses pytest fixtures to simulate SSH connection scenarios and host key verification failures. The implementation leverages pytest’s powerful fixture system for test data setup and cleanup.

Notable patterns include:

Fixture-based test environment setup
File system manipulation for known_hosts testing
Command object mocking
Platform-specific test skipping

Technical Details

Testing tools and configuration:

pytest as the primary testing framework
Custom Command type implementation
File-based fixtures for known_hosts simulation
Platform-specific test controls using pytest.mark.skipif
Monkeypatch utility for environment manipulation

Best Practices Demonstrated

The test suite exemplifies several testing best practices for Python applications.

Notable practices include:

Isolated test environments using temporary directories
Comprehensive error message validation
Clean setup and teardown procedures
Platform-aware test execution
Modular test case organization

nvbn/thefuck

tests/rules/test_ssh_known_host.py

            
import os
import pytest
from thefuck.rules.ssh_known_hosts import match, get_new_command, \
    side_effect
from thefuck.types import Command


@pytest.fixture
def ssh_error(tmpdir):
    path = os.path.join(str(tmpdir), 'known_hosts')

    def reset(path):
        with open(path, 'w') as fh:
            lines = [
                '123.234.567.890 asdjkasjdakjsd
'
                '98.765.432.321 ejioweojwejrosj
'
                '111.222.333.444 qwepoiwqepoiss
'
            ]
            fh.writelines(lines)

    def known_hosts(path):
        with open(path, 'r') as fh:
            return fh.readlines()

    reset(path)

    errormsg = u"""@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@    WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!     @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!
Someone could be eavesdropping on you right now (man-in-the-middle attack)!
It is also possible that a host key has just been changed.
The fingerprint for the RSA key sent by the remote host is
b6:cb:07:34:c0:a0:94:d3:0d:69:83:31:f4:c5:20:9b.
Please contact your system administrator.
Add correct host key in {0} to get rid of this message.
Offending RSA key in {0}:2
RSA host key for {1} has changed and you have requested strict checking.
Host key verification failed.""".format(path, '98.765.432.321')

    return errormsg, path, reset, known_hosts


def test_match(ssh_error):
    errormsg, _, _, _ = ssh_error
    assert match(Command('ssh', errormsg))
    assert match(Command('ssh', errormsg))
    assert match(Command('scp something something', errormsg))
    assert match(Command('scp something something', errormsg))
    assert not match(Command(errormsg, ''))
    assert not match(Command('notssh', errormsg))
    assert not match(Command('ssh', ''))


@pytest.mark.skipif(os.name == 'nt', reason='Skip if testing on Windows')
def test_side_effect(ssh_error):
    errormsg, path, reset, known_hosts = ssh_error
    command = Command('ssh user@host', errormsg)
    side_effect(command, None)
    expected = ['123.234.567.890 asdjkasjdakjsd
', '111.222.333.444 qwepoiwqepoiss
']
    assert known_hosts(path) == expected


def test_get_new_command(ssh_error, monkeypatch):
    errormsg, _, _, _ = ssh_error
    assert get_new_command(Command('ssh user@host', errormsg)) == 'ssh user@host'