Building command line

Pytest-mh provides a built in CLIBuilder class that helps with constructing a command line for execution, especially when using optional values since it can easily skip parameters that are set to None. There are three methods available within the class:

• command()

• argv()

• args()

args() processes the arguments, combines them with given values and returns the command line as a list. argv() works in the same way, but it returns the full argv list (including the command name) that is ready to be executed with exec() and finally command() returns a string that can be passed directly to run().

All methods take a dictionary, where key is the parameter name and value is a tuple of parameter type and its value. The parameter type is one of CLIBuilder.option value that can differentiate between positional, key-value or switch argument. This dictionary is then consumed by one of the methods, if a parameter value inside the tuple is None then this parameter is omitted.

Example of CLIBuilder.command

cli = CLIBuilder(Bash())
args: CLIBuilderArgs = {
    "password": (cli.option.VALUE, None),     # None values are ignored
    "home": (cli.option.VALUE, "/home/jdoe"), # --home '/home/jdoe'
    "enabled": (cli.option.SWITCH, True),     # --enabled
    "login": (cli.option.POSITIONAL, "jdoe"), # 'jdoe'
}

line = cli.command("add-user", args)
# add-user --home '/home/jdoe' --enabled 'jdoe'

Example of CLIBuilder.argv

cli = CLIBuilder(Bash())
args: CLIBuilderArgs = {
    "password": (cli.option.VALUE, None),     # None values are ignored
    "home": (cli.option.VALUE, "/home/jdoe"), # --home '/home/jdoe'
    "enabled": (cli.option.SWITCH, True),     # --enabled
    "login": (cli.option.POSITIONAL, "jdoe"), # 'jdoe'
}

line = cli.argv("add-user", args)
# ["add-user", "--home", "/home/jdoe", "--enabled", "jdoe"]

Example of CLIBuilder.args

cli = CLIBuilder(Bash())
args: CLIBuilderArgs = {
    "password": (cli.option.VALUE, None),     # None values are ignored
    "home": (cli.option.VALUE, "/home/jdoe"), # --home '/home/jdoe'
    "enabled": (cli.option.SWITCH, True),     # --enabled
    "login": (cli.option.POSITIONAL, "jdoe"), # 'jdoe'
}

line = cli.args(args)
# ["--home", "/home/jdoe", "--enabled", "jdoe"]

host.conn.run(f"user-add --encrypt-home {' '.join(line)}")

Note

There is also CLIBuilder.option.PLAIN. This option behaves similarly to CLIBuilder.option.VALUE but it does not quote the value (if quoting is enabled – which is the default behavior of command()), it just adds the value to the position as is.

Example of CLIBuilder.option.PLAIN

cli = CLIBuilder(Bash())
args: CLIBuilderArgs = {
    "password": (cli.option.PLAIN, "`encrypt-password 123456`"), # use value as-is
    "home": (cli.option.VALUE, "/home/jdoe"),                    # --home '/home/jdoe'
    "enabled": (cli.option.SWITCH, True),                        # --enabled
    "login": (cli.option.POSITIONAL, "jdoe"),                    # 'jdoe'
}

line = cli.command("add-user", args)
# add-user --password `encrypt-password 123456` --home '/home/jdoe' --enabled 'jdoe'