JavaScript Standard Style
One Style to Rule Them All
No decisions to make, no .jshintrc
or .jscs
files to manage. It just works.
Install
npm install standard
Rules
- 2 spaces for indentation
- Single quotes for strings
- Except to avoid escaping like
"in this lil' string"
- Unix line breaks (LF)
- No unused variables (this one catches so many bugs and typos!)
- No semicolons
- Never start a line with
(
or [
- This is the only gotcha with omitting semicolons – automatically checked for you!
- Always prefix with
;
like this ;[1, 2, 3].join(' ')
- Spaces after keywords
- Spaces before/after function definitions
function name (arg1, arg2) { ... }
- Always name the context variable
self
var self = this
- Checks for accidental use of
window.self
when var self = this
is omitted
- Always use
===
instead of ==
obj == null
is allowed for succinctness (obj === null || obj === undefined
)
- Always handle the node.js
err
function parameter
To get a better idea, take a look at
a sample file written
in JavaScript Standard Style.
Usage
The easiest way to use JavaScript Standard Style to check your code is to install it
globally as a Node command line program. To do so, simply run the following command in
your terminal (flag -g
installs standard
globally on your system, omit it if you want
to install in the current working directory):
npm install standard -g
After you've done that you should be able to use the standard
program. The simplest use
case would be checking the style of all JavaScript files in the current working directory:
$ standard
Error: Code style check failed:
lib/torrent.js:950:11: Expected '===' and instead saw '=='.
What you might do if you're clever
- Add it to
package.json
{
"name": "my-cool-package",
"devDependencies": {
"standard": "*"
},
"scripts": {
"test": "standard && node my-normal-tests.js"
}
}
- Check style automatically when you run
npm test
$ npm test
Error: Code style check failed:
lib/torrent.js:950:11: Expected '===' and instead saw '=='.
- Never give style feedback on a pull request again!
FAQ
Why would I use JavaScript Standard Style?
The beauty of JavaScript Standard Style is that it's simple. No one wants to maintain
multiple hundred-line .jshintrc
and .jscs
for every module/project they work on.
Enough of this madness!
This module saves you time in two ways:
- No configuration. Just drop it in. The easiest way to enforce consistent style in
your module/project.
- Catch style errors before they're submitted in PRs. Saves precious code review time
by eliminating back-and-forth between maintainer and contributor.
How do I ignore files?
The paths node_modules/
, .git/
, *.min.js
, and bundle.js
are automatically excluded
when looking for .js
files to style check.
Sometimes you need to ignore additional folders or specific minfied files. To do that, add
a standard.ignore
property to package.json
:
"standard": {
"ignore": [
"**/out/**",
"**/lib/select2/**",
"**/lib/ckeditor/**"
]
}
Is there an automatic formatter?
Yes, try using Max Ogden's experimental auto formatter
standard-format
to fix the easier
cases.
How do I hide a certain warning?
In rare cases, you'll need to break a rule and hide the warning generated by standard
.
JavaScript Standard Style uses jshint
and
jscs
under-the-hood and you can hide their warnings as you normally
would if you used each linter directly.
To get verbose output (so you can find the particular rule name to ignore), run:
$ standard --verbose
Error: Code style check failed:
routes/error.js:20:36: 'next' is defined but never used. (W098)
routes/submit.js:85:2: Expected indentation of 2 characters (validateIndentation)
The first warning is jshint
(always starts with a W
). You can hide it with a
/* jshint -W098 */
comment. Re-enable with a /* jshint +W098 */
comment.
Example:
app.use(function (err, req, res, next) {
res.render('error', { err: err })
})
The second warning is from jscs
(always a long camel-case string), which you can hide
with a // jscs:disable validateIndentation
comment. Re-enable with a
// jscs:enable validateIndentation
comment.
Can you please add more config options?
No. Use jshint
or jscs
directly if you want that.
Pro tip: Just use standard
and move on. There are actual real problems that you could
spend your time solving :p
License
MIT. Copyright (c) Feross Aboukhadijeh.