Write tests for parse_and_validate_args

[rusty-snake]

Some tests for parse_and_validate_args would be quite nice.

fdns4users/src/main.rs

Lines 61 to 102 in 2d08c76

	/// Parse and validate the arguments
	///
	/// The first argument must be `--proxy-addr=127.70.74.[0-9]{1,3}` or `--help`.
	/// All other arguments are optional. Currently supported are `--blocklist=[A-Za-z0-9._-]+` and
	/// `--whitelist=[A-Za-z0-9._-]+` in any order and number.
	fn parse_and_validate_args<T: Iterator<Item = String>>(args: &mut T) -> (String, Vec<String>) {
	// validate first commandline arg (--proxy-addr)
	let proxy_addr = {
	let arg_1 = args
	.next()
	.expect("No command-line arguments given. --proxy-addr must be given.");
	if arg_1 == "--help" {
	help()
	}
	if arg_1.starts_with("--proxy-addr=127.70.74.")
	&& arg_1[23..].chars().all(|c| c.is_ascii_digit())
	&& 24 <= arg_1.len()
	&& arg_1.len() <= 26
	{
	arg_1
	} else {
	panic!(
	"Invalid first argument, must be --help or --proxy-addr with a allowed IP-address."
	);
	}
	};
	// parse left over commandline args, keep only '--whitelist=[A-Za-z0-9._-]*'
	// and '--blocklist=[A-Za-z0-9._-]*'
	let fdns_args = args
	.filter(|arg| {
	(arg.starts_with("--blocklist=") || arg.starts_with("--whitelist="))
	&& arg[12..]
	.chars()
	.all(|c| c.is_ascii_alphanumeric() || c == '.' || c == '-' || c == '_')
	})
	.collect::<Vec<_>>();
	(proxy_addr, fdns_args)
	}