Requires or disallows a whitespace (space or tab) beginning a comment (spaced-comment)

Some style guides require or disallow a whitespace immediately after the initial // or /* of a comment. Whitespace after the // or /* makes it easier to read text in comments. On the other hand, commenting out code is easier without having to put a whitespace right after the // or /*.

Rule Details

This rule will enforce consistency of spacing after the start of a comment // or /*.

This rule takes two arguments. If the first is "always" then the // or /* must be followed by at least once whitespace. If "never" then there should be no whitespace following. The default is "always".

The second argument is an object with two keys, "exceptions" and "markers". The "exceptions" value is an array of string patterns which are considered exceptions to the rule. It is important to note that the exceptions are ignored if the first argument is "never".

Exceptions cannot be mixed. From the collection of exceptions provided only one of them can be used inside the comment. Mixing of more than one is not valid.

The "markers" value is an array of string patterns which are considered markers for docblock-style comments, such as an additional /, used to denote documentation read by doxygen, vsdoc, etc. which must have additional characters. The "markers" array will apply regardless of the value of the first argument, e.g. "always" or "never".

The following patterns are considered warnings:

// When ["never"]
// This is a comment with a whitespace at the beginning

// When ["never"]
/* This is a comment with a whitespace at the beginning */

// When ["never"]
/* \nThis is a comment with a whitespace at the beginning */

//When ["always"]
//This is a comment with no whitespace at the beginning
var foo = 5;

//When ["always"]
/*This is a comment with no whitespace at the beginning */
var foo = 5;

// When ["always",{"exceptions":["-","+"]}]
//------++++++++
// Comment block
//------++++++++

// When ["always",{"markers":["/"]}]
///This is a comment with a marker but without whitespace

// When ["always",{"exceptions":["-","+"]}]
/*------++++++++*/
/* Comment block */
/*------++++++++*/

The following patterns are not warnings:

// When ["always"]
// This is a comment with a whitespace at the beginning
var foo = 5;

// When ["always"]
/* This is a comment with a whitespace at the beginning */
var foo = 5;

// When ["always"]
/*\n * This is a comment with a whitespace at the beginning */
var foo = 5;

//When ["never"]
/*This is a comment with no whitespace at the beginning */
var foo = 5;

// When ["always",{"exceptions":["-"]}]
//--------------
// Comment block
//--------------

// When ["always",{"exceptions":["-+"]}]
//-+-+-+-+-+-+-+
// Comment block
//-+-+-+-+-+-+-+

// When ["always",{"exceptions":["-+"]}]
/*-+-+-+-+-+-+-+*/
// Comment block
/*-+-+-+-+-+-+-+*/

// When ["always",{"markers":["/"]}]
/// This is a comment with a marker

// When ["never",{"markers":["!<"]}]
//!<This is a comment with a marker
/*!<this is a block comment with a marker
subsequent lines are ignored
*/

// When ["always"]
/**
* I am jsdoc
*/

// When ["never"]
/**
* I am jsdoc
*/

Version

This rule was introduced in ESLint 0.23.0.

Resources