bddcli 2.5.1

Test any command line interface in BDD manner.

bddcli

Test any command line interface in BDD manner.

About

A framework to easily test your command line interface in another(isolated) process and gather stdout, stderr and returnStatus of the process.

Installation

Only Python >= 3.6 is supported.

pip install bddcli

Quickstart

Arguments

import sys

from bddcli import Given, when, stdout, status, stderr, Application, given


def foo():
    print(' '.join(sys.argv))
    return 0


app = Application('foo', 'mymodule:foo')


with Given(app, 'Pass single positional argument', 'bar'):
    assert status == 0
    assert stdout == 'foo bar\n'

    when('Without any argument', given - 'bar')
    assert stdout == 'foo\n'

    when('Pass multiple arguments', 'bar baz')
    assert stdout == 'foo bar baz\n'

    when('Pass multiple arguments, another method', ['bar', 'baz'])
    assert stdout == 'foo bar baz\n'

    when('Add an argument', given + 'baz')
    assert stdout == 'foo bar baz\n'

Standard input

with Given(app, 'Pass stdin', stdin='foo'):
    assert ...

    when('stdin is empty', stdin='')
    assert ...

Standard output and error

from bddcli import stderr, stdout

assert stderr == ... 
assert stdout == ... 

Environment variables

import os

from bddcli import Given, stdout, Application, when, given


def foo():
    e = os.environ.copy()
    del e['PWD']
    print(' '.join(f'{k}: {v}' for k, v in e.items()))


app = Application('foo', 'mymodule:foo')
with Given(app, 'Environment variables', environ={'bar': 'baz'}):
    assert stdout == 'bar: baz\n'

    when('Without any variable', environ=given - 'bar')
    assert stdout == '\n'

    when('Add another variables', environ=given + {'qux': 'quux'})
    assert stdout == 'bar: baz qux: quux\n'

See tests for more examples.