plus/curly-newline

A number of style guides require or disallow line breaks inside of block statements and block-like code.

Rule Details

This rule requires or disallows a line break between { and its following token, and between } and its preceding token of block-like structures.

Options

This rule has either a string option:

• "always" requires line breaks after opening and before closing braces
• "never" disallows line breaks after opening and before closing braces

Or an object option:

• "multiline": true requires line breaks if there are line breaks inside properties or between properties. Otherwise, it disallows line breaks.
• "minElements" requires line breaks if the number of elements in the block (usually statements) is at least the given integer. If consistent is set to true, an error will also be reported if a block contains linebreaks and has fewer elements than the given integer.
• "consistent": true (default) requires that either both curly braces, or neither, directly enclose newlines. Note that enabling this option will also change the behavior of the minElements option. (See minElements above for more information)

You can specify different options for different kinds of blocks:

{
    "curly-newline": ["error", {
        "ForInStatement": "always",
        "ForOfStatement": { "multiline": true },
        "ForStatement": "never",
        "WhileStatement": { "multiline": true, "minElements": 3, "consistent": true }
    }]
}

• "IfStatement" - An if statement body
• "ForStatement" - A for statement body
• "ForInStatement" - A for..in statement body
• "ForOfStatement" - A for..of statement body
• "WhileStatement" - A while statement body
• "DoWhileStatement" - A do..while statement body
• "SwitchStatement" - A switch statement body
• "SwitchCase" - A switch case body
• "TryStatementBlock" - A try..catch..finally statement main body
• "TryStatementHandler" - A try..catch..finally statement handler body
• "TryStatementFinalizer" - A try..catch..finally statement finalizer body
• "BlockStatement" - A lone block
• "FunctionDeclaration" - A function declaration body
• "FunctionExpression" - A function expression body
• "Property" - An object method shorthand body
• "ClassBody" - A class body
• "StaticBlock" - A static declaration block
• "WithStatement" - A with statement body
• "TSEnumBody" - A TypeScript enum declaration body
• "TSInterfaceBody" - A TypeScript interface declaration body
• "TSModuleBlock" - A TypeScript module block

always

Examples of incorrect code for this rule with the "always" option:

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

if (true) {}

if (true) { foo(); }
if (true) { foo(); bar(); }
if (true) { foo();
    bar(); };

if (true) { let a = {
    }; };

incorrect

Examples of correct code for this rule with the "always" option:

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

if (true) {
}
if (true) {
    foo();
}
if (true) {
    foo(); bar();
}
if (true) {
    foo();
    bar();
}
if (true) {
    let a = function() {
        foo();
    }
}

correct

never

Examples of incorrect code for this rule with the "never" option:

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

if (true) {
}
if (true) {
    foo();
}
if (true) {
    foo(); bar();
}
if (true) {
    foo();
    bar();
}
if (true) {
    let a = function() {
        foo();
    }
}

incorrect

Examples of correct code for this rule with the "never" option:

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

if (true) {}
if (true) { foo(); }
if (true) { foo(); bar(); }
if (true) { foo();
    bar(); };
if (true) { let a = {
    }; };

correct

multiline

Examples of incorrect code for this rule with the { "multiline": true } option:

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

if (true) {
}

if (true) {
    foo();
}
if (true) {
    foo(); bar();
}
if (true) { foo();
    bar(); };

if (true) { let a = {
    }; };

incorrect

Examples of correct code for this rule with the { "multiline": true } option:

/*eslint curly-newline: ["error", { "multiline": true }]*/
/*eslint-env es6*/

if (true) {}
if (true) { foo(); }
if (true) { foo(); bar(); }
if (true) {
    foo();
    bar();
}
if (true) {
    let a = {
    };
}

correct

minElements

Examples of incorrect code for this rule with the { "minElements": 2 } option:

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

if (true) {
}
if (true) {
    foo();
}
if (true) { foo(); bar(); }
if (true) { foo();
    bar(); }
if (true) {
    let a = {
    }
}

incorrect

Examples of correct code for this rule with the { "minElements": 2 } option:

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

if (true) {}
if (true) { foo(); }
if (true) {
    foo(); bar();
}
if (true) {
    foo();
    bar();
}
if (true) { var a = {
} }

correct

consistent

Examples of incorrect code for this rule with the default { "consistent": true } option:

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

if (true) { foo();
}
if (true) {
foo(); }
if (true) { foo(); bar();
}
if (true) {
foo(); bar(); }
if (true) { var a = {
    }
}
if (true) {
    var a = {
    }}

incorrect

Examples of correct code for this rule with the default { "consistent": true } option:

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

if (true) {}
if (true) {
}
if (true) { foo(); }
if (true) {
    foo();
}
if (true) {
    foo(); bar();
}
if (true) {
    foo();
    bar();
}

correct

When Not To Use It

If you don't want to enforce consistent line breaks after opening and before closing braces, then it's safe to disable this rule.

Related rules

• block-spacing
• brace-style
• object-curly-newline
• padded-blocks
• space-before-blocks