strict() and default() cause problem in command builder

[GongT]

main.js:

const ArgumentDefine = yargs
		.strict()
		// .command(require('./commands/init'))
		.commandDir('commands')
		.demandCommand(1);
console.log(ArgumentDefine.argv);

commands/init.js:

exports.command = 'init [target]';
exports.desc = 'Create the config files. (or update if exists)';
exports.builder = function builder(yargs) {
	return yargs
		.default('target', './')
		.demandCommand(0, 1, 'no way to show this', 'Too many arguments.')
		.strict();
};

node ./main.js init /tmp/xxx:

main.js init [target]

Options:
  --target                                                       [default: "./"]

Unknown argument: target

[GongT]

without strict(), I can run node main.js init /tmp/xxx -x -y -z without error.

without default(), I can't run node main.js init -x -y -z, but can't set a default value.

[bcoe]

@GongT from the docs:

Any command-line argument given that is not demanded, or does not have a corresponding description, will be reported as an error.

so if you describe target or demand target.

      yargs
        .default('target', 'blarg.js')
        .demand('target')
        .strict()

Things should start working for you. I can see the argument for making demand also be applied to arguments that are simply defaulted; it might be worth joining the conversation here #742, where we're discussing API improvements for version 7.x of yargs.