eslint-plugin-unicorn: Rule proposal: Don't pass default values to functions

Fail

function run(always = true) {}
run(true); // Error

function run({always} = {always: true}) {}
run({always: true}); // Error

function run({always = true} = {}) {}
run({always: true}); // Error

function run(options) {
	options = {
		always: true,
		...options
	}
}
run({always: true}); // Error

function run(options) {
	options = Object.assign({
		always: true
	}, options);
}
run({always: true}); // Error

And any other common defaults pattern (unless already blocked by other rules like prefer-object-spread)

Pass

run(); // No parameter set

Exclude

If run depends on arity/arguments.length

About this issue

Original URL
State: closed
Created 4 years ago
Comments: 19 (5 by maintainers)

Most upvoted comments

I never mentioned pay. It’s all about exposure.

fregante on Apr 9, 2020

@fregante You forgot to fix it in the ESLint issue 😅

papb on Apr 9, 2020

While I like the idea of this rule, I feel it’s not that useful when constrained to a single file. @fregante Maybe you could propose it over at https://github.com/typescript-eslint/typescript-eslint ?

sindresorhus on Jul 17, 2020

Actually your last example is wrong too haha, should be:

function run(options) {
	options = Object.assign({
		always: true
	}, options);
}
run({always: true}); // Error

papb on Apr 9, 2020

By the way, I also asked about this rule on eslint ⬇️

fregante on Apr 9, 2020

Your fourth example is not a “defaults pattern”… It is probably a mistake, since it overwrites the always option entirely… What you probably meant is:

function run(options) {
	options = {
		always: true,
		...options
	}
}
run({always: true}); // Error

papb on Apr 9, 2020