Add CLI test changes and explanation

[purplediane]

Location within the Course

• Section:5
• Lesson:1
• Language:English

Description

We create the CLI in 5.1 but we don't talk about how to make the test_command_line_interface in test_<package>.py work.

If there are inputs for the command line, they need to be specified as strings in a list as in result = runner.invoke(cli.main, ['4']).

Also, maybe because of the way we have a cli.py file, calling help_result = runner.invoke(cli.main, ['--help']) in the test code gives a different answer than <package> --help on the command line. Instead of "Usage: <package>", it returns "Usage: main".