Rule Proposal: object-curly-newline

[mysticatea]

From requirePaddingNewLinesInObjects and disallowPaddingNewLinesInObjects.

This will require/disallow line breaks after open object curlies and before close object curlies.

Options

{
    "object-curly-newline": [
        "error", 
        "always" or "never" or {"multiline": <boolean>, "minItems": <integer>}
    ]
}

• "always" - Requires line breaks always.
• "never" - Disallows line breaks always.
• An object - Requires line breaks if any of properties is satisfied. Otherwise, disallows line breaks.
  • multiline (default is false) - Requires line breaks if the content is multiline. If this is false, this condition is disabled.
  • minItems (default is 0) - Requires line breaks if the number of properties is more than the given integer. If this is 0, this condition is disabled.

Examples

/*eslint object-curly-newline: ["error", "always"]*/

// ✔ GOOD
let a = {
};
let b = {
    foo: 1
};
let c = {
    foo: 1, bar: 2
};
let d = {
    foo: 1,
    bar: 2
};
let e = {
    foo: function() {
        dosomething();
    }
};

// ✘ BAD
let a = {};
let b = {foo: 1};
let c = {foo: 1, bar: 2};
let d = {foo: 1,
    bar: 2};
let e = {foo() {
    dosomething();
}};

/*eslint object-curly-newline: ["error", "never"]*/

// ✔ GOOD
let a = {};
let b = {foo: 1};
let c = {foo: 1, bar: 2};
let d = {foo: 1,
    bar: 2};
let e = {foo: function() {
    dosomething();
}};

// ✘ BAD
let a = {
};
let b = {
    foo: 1
};
let c = {
    foo: 1, bar: 2
};
let d = {
    foo: 1,
    bar: 2
};
let e = {
    foo: function() {
        dosomething();
    }
};

/*eslint object-curly-newline: ["error", {"multiline": true}]*/

// ✔ GOOD
let a = {};
let b = {foo: 1};
let c = {foo: 1, bar: 2};
let d = {
    foo: 1,
    bar: 2
};
let e = {
    foo: function() {
        dosomething();
    }
};

// ✘ BAD
let a = {
};
let b = {
    foo: 1
};
let c = {
    foo: 1, bar: 2
};
let d = {foo: 1,
    bar: 2};
let e = {foo: function() {
    dosomething();
}};

/*eslint object-curly-newline: ["error", {"minItems": 2}]*/

// ✔ GOOD
let a = {};
let b = {foo: 1};
let c = {
    foo: 1, bar: 2
};
let d = {
    foo: 1,
    bar: 2
};
let e = {foo: function() {
    dosomething();
}};

// ✘ BAD
let a = {
};
let b = {
    foo: 1
};
let c = {foo: 1, bar: 2};
let d = {foo: 1,
    bar: 2};
let e = {
    foo: function() {
        dosomething();
    }
};

/*eslint object-curly-newline: ["error", {"multiline": true "minItems": 2}]*/

// ✔ GOOD
let a = {};
let b = {foo: 1};
let c = {
    foo: 1, bar: 2
};
let d = {
    foo: 1,
    bar: 2
};
let e = {
    foo: function() {
        dosomething();
    }
};

// ✘ BAD
let a = {
};
let b = {
    foo: 1
};
let c = {foo: 1, bar: 2};
let d = {foo: 1,
    bar: 2};
let e = {foo: function() {
    dosomething();
}};

Related Rules

	brace style	space style	line break style
block	brace-style	block-spacing	max-statements-per-line
object	#6072 object-curly-newline	object-curly-spacing	object-property-newline
array	#6073 array-bracket-newline	array-bracket-spacing	#6075 array-element-newline

[ilyavolodin]

I think we already have an issue opened for something like that, having trouble finding it now. I think proposal was to add option to brace-style for object literals.

[mysticatea]

For spacing, rules are separated each kind of braces. So my proposals are, too.

object-curly-spacing ⇔ newline-object-curly
array-bracket-spacing ⇔ newline-array-bracket
block-spacing ⇔ brace-style

Indeed, brace-style rule is doing more things than spacing rules, so my proposals may not be enough.

[mysticatea]

@ilyavolodin It seems to be closed already: #5203

[mysticatea]

I updated this proposal.
If there are not objection opinions, I want to implement this.

[ilyavolodin]

👍

[nzakas]

@eslint/eslint-team need some more feedback here.

👍

[BYK]

👍

[kaicataldo]

Unless there's already a convention to use items when referring to object props, I wonder if there is a better name for the minItems option. minProps/minProperties? A little more verbose, but that's the terminology I'm used to using/seeing.

Otherwise, 👍 from me

[nzakas]

@kaicataldo agreed, we should use "props" or "properties" for consistency

[mysticatea]

Thank you!

I'll update my PR by feedback.

[PhiLhoSoft]

#5203 isn't actually covered by this proposal.
For this, we would need a rule to "require/disallow line breaks BEFORE open object curlies" (and brackets too, in the other proposals).
Not sure if this must be included in this rule or addressed by a different rule.

[nzakas]

@PhiLhoSoft the goal here is not to implement a solution for #5203, it's to create an ESLint rule that is equivalent to two JSCS rules. Those rules only deal with inserting newlines inside of braces and that's what this issue is implementing.

[PhiLhoSoft]

Yes, I was answering the comment #6072 (comment) actually, referring to the above issue.