#comma-style

#Configuration

import { defineConfig, stylisticPlugin } from '@rslint/core';

export default defineConfig([
  stylisticPlugin.configs.recommended,
  {
    rules: {
      '@stylistic/comma-style': 'error',
    },
  },
]);

Enforce consistent comma style.

#Rule Details

This rule enforces a consistent comma placement across comma-separated lists in JavaScript and TypeScript — array literals, object literals, variable declarations, function parameters, call arguments, import / export specifiers, sequence expressions, and the TypeScript-only lists (type / interface members, enum members, tuples, type parameters and type arguments, function / constructor signatures, import attributes).

The rule does NOT flag commas in single-line lists. A comma surrounded by linebreaks on both sides (a "lone" comma) reports under its own message regardless of the configured style.

#Options

This rule has a string option:

• "last" (default) — commas at the end of the current line.
• "first" — commas at the start of the next line.

This rule has an object option:

• "exceptions" — disables the rule for specific AST node types. Keys match the upstream ESTree / @typescript-eslint/parser node-type names so configuration is portable from ESLint Stylistic. Supported keys: ArrayExpression, ArrayPattern, ObjectExpression, ObjectPattern, VariableDeclaration, FunctionDeclaration, FunctionExpression, ArrowFunctionExpression, CallExpression, NewExpression, ImportExpression, ImportDeclaration, ExportNamedDeclaration, ExportAllDeclaration, SequenceExpression, ClassDeclaration, ClassExpression, TSDeclareFunction, TSFunctionType, TSConstructorType, TSEmptyBodyFunctionExpression, TSMethodSignature, TSCallSignatureDeclaration, TSConstructSignatureDeclaration, TSEnumBody, TSTypeLiteral, TSInterfaceBody, TSInterfaceDeclaration, TSIndexSignature, TSTupleType, TSTypeParameterDeclaration, TSTypeParameterInstantiation.

#last

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

var foo = 1
,
bar = 2;

var foo = 1
  , bar = 2;

var foo = ["apples"
           , "oranges"];

function baz() {
  return {
    a: 1
    , b: 2
  };
}

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

var foo = 1, bar = 2;

var foo = 1,
    bar = 2;

var foo = ["apples",
           "oranges"];

function baz() {
  return {
    a: 1,
    b: 2,
  };
}

#first

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

{ "@stylistic/comma-style": ["error", "first"] }

var foo = 1,
    bar = 2;

var foo = ["apples",
           "oranges"];

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

{ "@stylistic/comma-style": ["error", "first"] }

var foo = 1, bar = 2;

var foo = 1
    ,bar = 2;

var foo = ["apples"
          ,"oranges"];

#exceptions

Examples of correct code for this rule with "first", { "exceptions": { "ArrayExpression": true, "ObjectExpression": true } }:

{ "@stylistic/comma-style": ["error", "first", { "exceptions": { "ArrayExpression": true, "ObjectExpression": true } }] }

var ar = {fst:1,
          snd: [1,
                2]}
  , a = [];

#Original Documentation

• @stylistic/comma-style