External Test Plugin
Overview
The External Test Plugin supports testing of a cmd2 application by exposing access to cmd2 commands with the same context as from within a cmd2 Python Script. This interface captures stdout
, stderr
, as well as any application-specific data returned by the command. This also allows for verification of an application's support for Python Scripts and enables the cmd2 application to be tested as part of a larger system integration test.
Example cmd2 Application
The following short example shows how to mix in the external test plugin to create a fixture for testing your cmd2 application.
Define your cmd2 application
import cmd2
class ExampleApp(cmd2.Cmd):
"""An class to show how to use a plugin"""
def __init__(self, *args, **kwargs):
# gotta have this or neither the plugin or cmd2 will initialize
super().__init__(*args, **kwargs)
def do_something(self, arg):
self.last_result = 5
self.poutput('this is the something command')
Defining the test fixture
In your test, define a fixture for your cmd2 application
import cmd2_ext_test
import pytest
class ExampleAppTester(cmd2_ext_test.ExternalTestMixin, ExampleApp):
def __init__(self, *args, **kwargs):
# gotta have this or neither the plugin or cmd2 will initialize
super().__init__(*args, **kwargs)
@pytest.fixture
def example_app():
app = ExampleAppTester()
app.fixture_setup()
yield app
app.fixture_teardown()
Writing Tests
Now write your tests that validate your application using the cmd2_ext_test.ExternalTestMixin.app_cmd
function to access the cmd2 application's commands. This allows invocation of the application's commands in the same format as a user would type. The results from calling a command matches what is returned from running an python script with cmd2's run_pyscript command, which provides stdout
, stderr
, and the command's result data.