Disallow multiple spaces (no-multi-spaces)

It’s a good practice to add whitespace in expressions to enhance readability of code such as:


if(foo === "bar") {}

In cases where more than one whitespace is added, it can lead to ugly and inconsistent looking code such as:


if(foo  === "bar") {}

Rule Details

This rule aims to disallow multiple whitespace around logical expressions, conditional expressions, declarations, array elements, object properties, sequences and function parameters.

The following patterns are considered warnings:

var a =  1;

if(foo   === "bar") {}

a <<  b

var arr = [1,  2];

a ?  b: c

The following patterns are not warnings:

var a = 1;

if(foo === "bar") {}

a << b

var arr = [1, 2];

a ? b: c

Exceptions

Some rules, like key-spacing in one of its alignment modes, might require multiple spaces in some instances. To support this case, this rule accepts an options object with a property named exceptions. Excepted node types can be added as properties on the exceptions object with their value set to true. Property nodes are excepted by default.

With this option, the following patterns are not warnings:

/* eslint no-multi-spaces: 2 */
/* eslint key-spacing: [2, { align: "value" }] */
var obj = {
    first:  "first",
    second: "second"
};

/* eslint no-multi-spaces: [2, { exceptions: { "BinaryExpression": true } }] */
var a = 1  *  2;

The default Property exception can be disabled by setting it to false, so the following pattern is considered a warning:

/* eslint no-multi-spaces: [2, { exceptions: { "Property": false } }] */
/* eslint key-spacing: [2, { align: "value" }] */
var obj = {
    first:  "first",
    second: "second"
};

When Not To Use It

If you don’t want to check and disallow multiple spaces, then you should turn this rule off.

Version

This rule was introduced in ESLint 0.9.0.

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