space-infix-ops

While formatting preferences are very personal, a number of style guides require spaces around operators, such as:

var sum = 1 + 2;

Proponents of this rule believe that it makes code easier to read and can more easily highlight potential errors, such as:

var sum = i+++2;

While this is valid JavaScript syntax, it is hard to determine what the author intended.

Rule Details

This rule is aimed at ensuring there are spaces around infix operators.

Options

This rule accepts a single options argument with the following defaults:

"space-infix-ops": ["error", { "int32Hint": false, "ignoreOperators": [], "ignoreTypes": false }]

int32Hint

Set the int32Hint option to true (default is false) to allow write a|0 without space.

var foo = bar|0; // `foo` is forced to be signed 32 bit integer

Examples of incorrect code for this rule:

/* eslint @stylistic/space-infix-ops: "error" */

a
+
b

a
+
 b

a 
+
b

a
?
b
:
c

const a
=
{b:1};

var {b
=
0}
=
bar;

function foo(a
=
0) { }

type Foo<T
=
true> = T

incorrect

Examples of correct code for this rule:

/* eslint @stylistic/space-infix-ops: "error" */

a + b

a       + b

a ? b : c

const a = {b:1};

var {b = 0} = bar;

function foo(a = 0) { }

type Foo<T = true> = T

correct

ignoreOperators

Set the ignoreOperators option to a list of operators that should not require surrounding spaces. Operators are matched by their exact text, so ignoring + does not ignore +=.

"space-infix-ops": ["error", { "ignoreOperators": ["*", "/", "^"] }]

With this configuration, a^b + c*d + e/f is valid while + is still checked.

ignoreTypes

Set the ignoreTypes option to true (default is false) to allow write string|number without space.

var foo: string|number = bar;

When Not To Use It

You can turn this rule off if you are not concerned with the consistency of spacing around infix operators.

Changelog

Not released yet

• feat545282aadd ignoreOperators option (#1243)

v6.0.0-beta.1 on 3/10/2026

• fixb14b45ehandle constraints in TSTypeParameter (#1164)