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common-style-3.1.0
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The most common choices by most JavaScript developers, probably
| ویژگی | مقدار |
|---|---|
| سیستم عامل | - |
| نام فایل | common-style-3.1.0 |
| نام | common-style |
| نسخه کتابخانه | 3.1.0 |
| نگهدارنده | ['indexzero'] |
| ایمیل نگهدارنده | ['charlie.robbins@gmail.com'] |
| نویسنده | Charlie Robbins |
| ایمیل نویسنده | charlie.robbins@gmail.com |
| آدرس صفحه اصلی | git+https://github.com/indexzero/common-style.git |
| آدرس اینترنتی | https://github.com/indexzero/common-style |
| مجوز | MIT |
# Common Style for JavaScript
> If you have comments on this or **disagree about rules** then
> please reach out to me directly. I want to hear it!
## Table of Contents
**_Basics_**
* [Compliance Levels](#compliance-levels)
* [Ground Rules](#ground-rules)
* [Semicolons](#semicolons)
* [Braces](#braces)
**_Identifiers and Primitives_**
* [Naming Contentions](#naming-conventions)
* [Variable Declarations](#variable-declarations)
* [Objects](#objects)
* [Arrays](#arrays)
* [Strings](#strings)
* [Comments](#code-comments)
* [Constructors](#constructors)
**_Statements and Techniques_**
* [Control-flow](#control-flow)
* [Functions](#function)
* [Conditionals](#conditionals)
* [Type Casting & Coercion](#type-casting--coercion)
* [Ternary Operators](#ternary-operators)
* [Errors](#errors)
* [Exports](#exports)
* [Async](#async-programming)
> [Attribution](#attribution)
## Compliance Levels
### GOOD and BAD
* **always / must**: This is **_mandatory_**. _Seriously_
* **never / must not**: Don't **_ever_** do this. Seriously.
### OK
* **should**: **_Try to_** do this. It is encouraged but not strictly enforced.
* **should not**: **_Try not to_** do this. It is discouraged but not prohibited.
## Ground Rules
- **RULE**: **Always** 2-space soft indents (no tabs)
- **RULE**: **Always** semicolons (with [one exception](#semicolons)).
- **RULE**: **Never use comma first**
- **RULE**: **Never use** `()` around statements like `typeof` or `delete`.
## Semicolons
- **RULE**: Semicolons `;` **must** be added at the end of every statement, **except** when the next character is a closing bracket `}`. In that case, they may be omitted.
``` js
//
// GOOD
//
var f = function add(a, b) {
if (a == b) { return a * 2 } // No `;` here.
return a + b;
};
```
``` js
//
// BAD
//
var f = function add (a, b) {
return a + b
}
```
**[[⬆]](#table-of-contents)**
## Braces
- **RULE**: Braces **must** be used in all circumstances. They **may** be used on a single line around simple statements.
``` js
//
// GOOD
//
if (x) { return true }
```
``` js
//
// BAD
//
if (x)
while (1)
i ++;
else
//...
```
``` js
//
// BAD
//
if (x) return true;
```
``` js
//
// BAD
//
if (x)
return true;
```
<hr>
- **RULE**: Opening Braces **must never** be on a line of their own.
- **Rule**: Closing braces **must never** be followed by a conditional statement
> Vertical screen space is precious, and ease of scanning code
> is more previous.
``` js
//
// GOOD
//
if (x) {
return true;
}
else {
return false;
}
```
``` js
//
// BAD
//
if (x)
{
return true;
}
```
``` js
//
// BAD
//
if (x) {
return true; }
```
``` js
//
// BAD
//
if (x) {
return true;
} else {
return false
}
```
<hr>
- **RULE**: Closing Braces **must always** be on a line of their own unless they also start on that line.
> This makes it easy to see the end of a function or statement
``` js
//
// GOOD
//
return callback && callback({ foo: bar });
```
``` js
//
// GOOD
//
return callback && callback({
foo: bar
});
```
``` js
//
// BAD
//
return callback && callback({
foo: bar });
```
``` js
//
// BAD
//
return callback && callback({ foo: bar
});
```
**[[⬆]](#table-of-contents)**
## Naming Conventions
- **RULE**: Avoid single letter names. Be descriptive with your naming.
``` js
//
// BAD
//
function q() {
// ...stuff...
}
//
// GOOD
//
function query() {
// ..stuff..
}
```
<hr>
- **RULE**: Use camelCase when naming objects, functions, and instances
``` js
//
// BAD
//
var OBJEcttsssss = {};
var this_is_my_object = {};
var this-is-my-object = {};
function c() {};
var u = new user({
name: 'Bob Parr'
});
//
// GOOD
//
var thisIsMyObject = {};
function thisIsMyFunction() {};
var user = new User({
name: 'Bob Parr'
});
```
<hr>
- **RULE**: Use PascalCase when naming constructors or classes
``` js
// BAD
function user(options) {
this.name = options.name;
}
var bad = new user({
name: 'nope'
});
// GOOD
function User(options) {
this.name = options.name;
}
var good = new User({
name: 'yup'
});
```
<hr>
- **RULE**: Use a leading underscore `_` when naming private properties
``` js
// BAD
this.__firstName__ = 'Panda';
this.firstName_ = 'Panda';
// GOOD
this._firstName = 'Panda';
```
<hr>
- **RULE**: Saved references to `this` (which is a prototypal object) **must** use `self`.
``` js
function User (options) {
this.setup();
}
//
// GOOD
//
User.prototype.setup = function () {
var self = this;
setTimeout(function () {
self.ready = true
}, 1000);
};
//
// BAD
//
User.prototype.setup = function () {
var that = this;
setTimeout(function () {
that.ready = true
}, 1000);
};
```
<hr>
- **RULE**: Saved references to `this` (which is an arbitrary scope) **should** use `that`.
``` js
//
// BAD
//
function () {
var self = this;
return function() {
console.log(self);
};
}
//
// BAD
//
function () {
var _this = this;
return function() {
console.log(_this);
};
}
//
// GOOD
//
function () {
var that = this;
return function() {
console.log(that);
};
}
```
<hr>
- **RULE**: Functions **should** be named. This is helpful for stack traces.
``` js
//
// OK
//
var log = function(msg) {
console.log(msg);
};
//
// GOOD
//
var log = function log(msg) {
console.log(msg);
};
```
**[[⬆]](#table-of-contents)**
## Variable declarations
- **RULE**: Variables **must** always be declared, prior to use.
- **RULE**: Variable declarations **must** appear at the top of functions, and not inside other blocks. The exception is *for* loops.
> Variable declarations are moved up to the top of the function
> scope anyway, so that's where they belong.
``` js
//
// GOOD
//
function (a, b) {
var k;
if (a == b) {
k = true;
}
//...
}
for (var i = 0; i < l; i ++) {
//...
}
```
``` js
//
// BAD
//
function (a, b) {
if (a == b) {
var k = true;
}
//...
}
```
<hr>
- **RULE**: Variables **must** always align when they are declared
> This makes it easy to scan what is declared in a single block.
``` js
//
// GOOD
//
var bazz,
foo,
bar;
```
``` js
//
// BAD
//
var bazz,
foo,
bar;
```
<hr>
- **RULE**: Declare unassigned variables last.
> This is helpful when later on you might need to assign a variable depending on one of the previous assigned variables.
``` js
//
// BAD
//
var i, len, dragonball,
items = getItems(),
goSportsTeam = true;
//
// BAD
//
var i, items = getItems(),
dragonball,
goSportsTeam = true,
len;
//
// GOOD
//
var items = getItems(),
goSportsTeam = true,
dragonball,
length,
i;
```
<hr>
- **RULE**: Variables **should** always be declared in decreasing length.
> This also makes it easier to scan what is declared in a single block (trust me).
``` js
//
// GOOD
//
var reallyLongVar,
shorterVar,
fooBar,
foo;
```
``` js
//
// BAD
//
var fooBar,
shorterVar,
foo,
reallyLongVar;
```
<hr>
- **RULE**: Variable assignments **must** come before declarations.
- **RULE**: Variable assignments **should** align **when convenient** depending on additional length.
> This also makes it easier to scan what is declared in a single block (trust me).
``` js
//
// GOOD
//
var reallyLongVar = 10e3,
shorterVar = 5e2,
fooBar = 'foobar',
foo;
```
``` js
//
// OK
//
var reallyLongVar = 10e3,
shorterVar = 5e2,
fooBar = 'foobar',
foo;
```
``` js
//
// BAD
//
var foo,
reallyLongVar = 10e3,
shorterVar = 5e2,
fooBar = 'foobar';
```
<hr>
- **RULE**: Multi-line object literals **must be** assigned outside of multi-line variable declaration blocks.
> It's what god would have wanted.
``` js
//
// GOOD
//
var obj = { list: [], expired: false },
bazz = 100,
foo,
bar;
```
``` js
//
// GOOD
//
var bazz = 100,
foo,
bar,
obj;
obj = {
list: [],
expired: false
};
```
``` js
//
// BAD
//
var obj = {
list: [],
expired: false
},
bazz = 100,
foo,
bar;
```
``` js
//
// BAD
//
var bazz = 100,
foo,
bar,
obj = {
list: [],
expired: false
};
```
<hr>
- **RULE**: Assignment depending on multi-line functions or multiple functions **must be** assigned outside of multi-line variable declaration blocks.
``` js
//
// GOOD
//
var memo = list.filter(function (i) { return i < 10 }),
bazz = 100,
foo,
bar;
```
``` js
//
// GOOD
//
var bazz = 100,
memo,
foo,
bar;
memo = list.filter(function (i) {
return i < 10;
}).filter(Boolean);
```
``` js
//
// BAD
//
var memo = list.filter(function (i) {
return i < 10
}),
bazz = 100,
foo,
bar;
```
``` js
//
// BAD
//
var bazz = 100,
foo,
bar,
memo = list.filter(function (i) {
return i < 10;
}).filter(Boolean);
```
``` js
//
// BAD
//
var bazz = 100,
foo,
bar,
memo = list.filter(function (i) { return i < 10 })
.filter(Boolean);
```
**[[⬆]](#table-of-contents)**
## Objects
- **RULE**: Single line object **must** have a trailing space after `{` and a leading space before `}`.
``` js
//
// BAD
//
var foo = {bar: 1};
```
``` js
//
// BAD
//
return {bar: 1};
```
``` js
//
// GOOD
//
var foo = { bar: 1 };
```
``` js
//
// GOOD
//
return { bar: 1 };
```
<hr>
- **RULE**: Properties in objects **must** be followed by a `:`
``` js
//
// BAD
//
var foo = { bar:1 };
```
``` js
//
// BAD
//
var foo = {
bar : 1,
bazz : 1
};
```
``` js
//
// GOOD
//
var foo = { bar: 1 };
```
``` js
//
// GOOD
//
var foo = {
bar: 1,
bazz: 1
};
```
``` js
//
// GOOD
//
var foo = {
bar: 1,
bazz: 1
};
```
<hr>
- **RULE**: Multi-line assignment statements **inside an object literal** are **encouraged.**
> Reduces the number of variables managed and object creation is cheap.
``` js
//
// GOOD
//
return {
foos: list.filter(function (i) {
return i.type === 'foo';
}),
bars: list.filter(function (i) {
return i.type === 'bar';
})
}
```
<hr>
- **RULE**: Use the literal syntax for object creation.
``` js
//
// BAD
//
var item = new Object();
//
// GOOD
//
var item = {};
```
- Using [reserved words](https://developer.mozilla.org/en-US/docs/JavaScript/Reference/Reserved_Words) is fine as _it is valid Javascript._
``` js
//
// OK
//
var superman = {
class: 'superhero',
default: { clark: 'kent' },
private: true
};
```
**[[⬆]](#table-of-contents)**
## Arrays
- **RULE**: Use the literal syntax for array creation
``` js
//
// BAD
//
var items = new Array();
// GOOD
var items = [];
```
<hr>
- **RULE**: If you don't know array length use Array#push.
``` js
var someStack = [];
//
// BAD
//
someStack[someStack.length] = 'abracadabra';
//
// GOOD
//
someStack.push('abracadabra');
```
<hr>
- **RULE**: When you need to copy an array use Array#slice. [jsPerf](http://jsperf.com/converting-arguments-to-an-array/7)
``` js
var len = items.length,
itemsCopy = [],
i;
//
// BAD
//
for (i = 0; i < len; i++) {
itemsCopy[i] = items[i];
}
//
// GOOD
//
itemsCopy = items.slice();
```
**[[⬆]](#table-of-contents)**
## Strings
- **RULE**: Use single quotes `''` for strings
``` js
//
// BAD
//
var name = "Bob Parr";
//
// GOOD
//
var name = 'Bob Parr';
//
// BAD
//
var fullName = "Bob " + this.lastName;
//
// GOOD
//
var fullName = 'Bob ' + this.lastName;
```
<hr>
- **RULE**: Strings longer than 80 characters should be written across multiple lines using string concatenation.
> If overused, long strings with concatenation could impact performance. [jsPerf](http://jsperf.com/ya-string-concat) & [Discussion](https://github.com/airbnb/javascript/issues/40)
``` js
//
// BAD
//
var errorMessage = 'This is a super long error that was thrown because of Batman. When you stop to think about how Batman had anything to do with this, you would get nowhere fast.';
//
// BAD
//
var errorMessage = 'This is a super long error that \
was thrown because of Batman. \
When you stop to think about \
how Batman had anything to do \
with this, you would get nowhere \
fast.';
//
// GOOD
//
var errorMessage = 'This is a super long error that ' +
'was thrown because of Batman.' +
'When you stop to think about ' +
'how Batman had anything to do ' +
'with this, you would get nowhere ' +
'fast.';
//
// GOOD
//
var errorMessage = [
'This is a super long error that ',
'was thrown because of Batman.',
'When you stop to think about',
'how Batman had anything to do',
'with this, you would get nowhere'
'fast.'
].join(' ');
```
<hr>
- **RULE**: When programatically building up a string, use Array#join instead of string concatenation. Mostly for IE: [jsPerf](http://jsperf.com/string-vs-array-concat/2).
``` js
var items,
messages,
length,
i;
messages = [{
state: 'success',
message: 'This one worked.'
}, {
state: 'success',
message: 'This one worked as well.'
}, {
state: 'error',
message: 'This one did not work.'
}];
length = messages.length;
//
// BAD
//
function inbox(messages) {
items = '<ul>';
for (i = 0; i < length; i++) {
items += '<li>' + messages[i].message + '</li>';
}
return items + '</ul>';
}
//
// GOOD
//
function inbox(messages) {
items = [];
for (i = 0; i < length; i++) {
items[i] = messages[i].message;
}
return '<ul><li>' + items.join('</li><li>') + '</li></ul>';
}
```
**[[⬆]](#table-of-contents)**
## Code Comments
- **RULE**: You **should not** use JSDoc.
- **RULE**: Block comments **should only** be used in file headers.
- **RULE**: You **should not** use single-line block comments
- **RULE**: Put an emptyline before a comment.
> Having appropriate space in your code comments makes writing
> complex code easier to read. It's the "almost literate coding"
> approach.
- **REMARK**: JSDoc should be considered **deprecated.** When time is available to improve the `docco`-style comments we have historically used we will replace it all together.
### GOOD
``` js
/*
* a-js-file.js: This is some file
*
* (C) 2013 Whomever
* MIT LICENSE
*
*/
```
``` js
//
// ### function myFunction (a, b, c)
// #### @a {string} A variable
// #### @b {boolean} Another variable
// #### @c {object|Array} An object or an array
//
// This is the description to my function.
//
```
``` js
//
// Adding additional padding in your code comments
//
var a = 0;
//
// Along with additional whitespace
//
if (!a) {
console.log('Makes your code easier to read.');
console.log('What are you running out of bytes?');
}
```
### OK
``` js
// One line comments
var a = 0;
// and no whitespace
if (!a) {
console.log('make your code harder to read');
console.log('seriously.');
}
```
``` js
/*
* I'm using block comments anywhere but the file header.
*/
```
<hr>
- **RULE**: Use `// FIXME:` to annotate problems.
- **RULE**: Use `// TODO:` to annotate solutions to problems.
- **RULE**: Use `// REMARK:` to annotate possible annotations or open implementation questions (which are not obvious problems).
- **RULE**: Sign these comments with your Github username.
### GOOD
``` js
function Calculator() {
// FIXME (index zero): shouldn't use a global here
total = 0;
return this;
}
```
``` js
function Calculator() {
// TODO (indexzero): total should be configurable by an options param
this.total = 0;
return this;
}
```
### BAD
``` js
function Calculator() {
// shouldn't use a global here
total = 0;
return this;
}
```
``` js
function Calculator() {
// TODO: total should be configurable by an options param
this.total = 0;
return this;
}
```
**[[⬆]](#table-of-contents)**
## Constructors
- **RULE**: Assign methods to the prototype object. You **must never** overwrite the prototype with a new object completely.
> Overwriting the prototype makes inheritance impossible: by resetting the prototype you'll overwrite the base!
``` js
function Jedi() {
console.log('new jedi');
}
//
// BAD
//
Jedi.prototype = {
fight: function fight() {
console.log('fighting');
},
block: function block() {
console.log('blocking');
}
};
//
// GOOD
//
Jedi.prototype.fight = function fight() {
console.log('fighting');
};
Jedi.prototype.block = function block() {
console.log('blocking');
};
```
<hr>
- **RULE**: Methods can return `this` to help with method chaining.
``` js
//
// OK
//
Jedi.prototype.jump = function() {
this.jumping = true;
return true;
};
Jedi.prototype.setHeight = function(height) {
this.height = height;
};
var luke = new Jedi();
luke.jump(); // => true
luke.setHeight(20) // => undefined
//
// GOOD
//
Jedi.prototype.jump = function() {
this.jumping = true;
return this;
};
Jedi.prototype.setHeight = function(height) {
this.height = height;
return this;
};
var luke = new Jedi();
luke.jump()
.setHeight(20);
```
<hr>
- **RULE**: It's okay to write a custom toString() method, just make sure it works successfully and causes no side effects.
``` js
function Jedi(options) {
options || (options = {});
this.name = options.name || 'no name';
}
Jedi.prototype.getName = function getName() {
return this.name;
};
Jedi.prototype.toString = function toString() {
return 'Jedi - ' + this.getName();
};
```
**[[⬆]](#table-of-contents)**
## Control-flow
- **RULE**: Control-flow statements, such as `if`, `while` and `for` **must** have a space between the keyword and the left parenthesis.
> They aren't functions, and thus better distinguished like this.
``` js
//
// GOOD
//
if (a) {
return true;
}
```
``` js
//
// BAD
//
if(a) {
return true;
}
```
<hr>
- **RULE**: Eager returns **must be** preferred over `if else` blocks.
> Eager returns simplifies most control-flow, especially more complex and high-level control-flow.
``` js
//
// BAD
//
if (foo) {
callback(null, 'foo');
}
else {
callback(null, 'bar');
}
```
``` js
//
// GOOD
//
if (foo) {
return callback(null, 'foo');
}
callback(null, 'bar');
```
**[[⬆]](#table-of-contents)**
## Functions
- **RULE**: Anonymous functions **must** have a space between the `function` keyword and the left parenthesis.
> To emphasise the lack of identifier and differentiate them with named functions.
``` js
//
// GOOD
//
function (a, b) {}
```
``` js
//
// BAD
//
function(a, b) {}
```
<hr>
- **RULE**: Named functions **must not** have a space between the function name and the left parenthesis.
- **RULE**: Function calls **must not** have a space between the function name and the left parenthesis.
``` js
//
// GOOD
//
function add(a, b) {}
```
``` js
//
// BAD
//
function add (a, b) {}
```
**[[⬆]](#table-of-contents)**
## Conditionals
- **RULE**: Multi-line conditional statements **must** be properly indented.
- **RULE**: Newlines in multi-line conditional statements **must** be be followed by a boolean operator or `(`.
- **RULE**: Conditional **should not** contain complex logic.
``` js
//
// GOOD
//
if (something === 'foo' && (somethingElse === 'bar'
&& ohYeahThisToo === 'bazz')) {
return false;
}
```
``` js
//
// BAD
//
if (something === 'foo' && (somethingElse === 'bar' &&
ohYeahThisToo === 'bazz')) {
return false;
}
```
``` js
//
// BAD
//
if (something === 'foo' && (somethingElse === 'bar' &&
ohYeahThisToo === 'bazz') {
return false;
}
```
``` js
//
// OK
//
if (list.filter(function (i) { return i.ok }).length > 5) {
return false;
}
```
**[[⬆]](#table-of-contents)**
## Type Casting & Coercion
- **RULE**: Perform type coercion at the beginning of the statement.
``` js
// => this.reviewScore = 9;
//
// BAD
//
var totalScore = this.reviewScore + '';
//
// GOOD
//
var totalScore = '' + this.reviewScore;
//
// BAD
//
var totalScore = '' + this.reviewScore + ' total score';
//
// GOOD
//
var totalScore = this.reviewScore + ' total score';
```
<hr>
- **RULE**: Use `parseInt` for Numbers and always with a radix for type casting.
> If for whatever reason you are doing something wild and `parseInt` is your bottleneck and need
> to use Bitshift for [performance reasons](http://jsperf.com/coercion-vs-casting/3), leave a comment explaining why and what you're doing.
**Numbers**
``` js
var inputValue = '4';
//
// OK
//
var val = +inputValue;
//
// BAD
//
var val = new Number(inputValue);
//
// BAD
//
var val = inputValue >> 0;
//
// BAD
//
var val = parseInt(inputValue);
//
// GOOD
//
var val = Number(inputValue);
//
// GOOD
//
var val = parseInt(inputValue, 10);
//
// GOOD
//
//
// parseInt was the reason my code was slow.
// Bitshifting the String to coerce it to a
// Number made it a lot faster.
//
var val = inputValue >> 0;
```
**Booleans**
``` js
var age = 0;
//
// BAD
//
var hasAge = new Boolean(age);
//
// GOOD
//
var hasAge = Boolean(age);
//
// GOOD
//
var hasAge = !!age;
```
**[[⬆]](#table-of-contents)**
## Ternary operators
- **RULE**: Ternary operators are OK, but **must never be combined**.
> More than one and it's spaghetti.
``` js
//
// GOOD
//
var i = 2,
x = i > 5 ? i : 0;
```
``` js
//
// BAD
//
var i = 2,
j = 3,
x = i > 5 ? j > 4 ? j : i : 0;
```
<hr>
- **RULE**: Multi-line Ternary operators are OK, but **must be single line statements.**.
``` js
//
// GOOD
//
return foo
? foo + 1
: bar;
```
``` js
//
// GOOD
//
return foo ? foo + 1 : bar;
```
``` js
//
// GOOD
//
return foo
? function () { return foo + 1 }
: bar;
```
``` js
//
// GOOD
//
return err
? callback(err)
: callback();
```
``` js
//
// BAD
//
return foo ?
foo + 1 :
bar;
```
``` js
//
// BAD
//
return foo
? foo + 1 :
bar;
```
``` js
//
// BAD
//
return foo
? function (wtf) {
return foo + 1; // No multi-line return values!
}
: bar;
```
<hr>
- **RULE**: Ternary operators combined with `return` **should be** preferred over `if (err) { return }` blocks.
``` js
//
// OK
//
if (err) {
return callback(err);
}
callback();
```
``` js
//
// GOOD
//
return err
? callback(err)
: callback();
```
**[[⬆]](#table-of-contents)**
## Errors
- **RULE**: You **must always** throw or return an error. [A string is not an Error](http://www.devthought.com/2011/12/22/a-string-is-not-an-error/).
> If you want more descriptive Errors, use [errs](https://github.com/flatiron/errs).
``` js
//
// GOOD
//
throw new Error('I have a call-stack and other good things.');
```
``` js
//
// GOOD
//
callback(new Error('I have a call-stack and other good things.'));
```
``` js
//
// BAD
//
throw 'I have no call-stack no interesting properties.';
```
``` js
//
// BAD
//
callback('I have no call-stack no interesting properties.');
```
``` js
//
// BAD
//
throw { message: 'I have no call-stack no interesting properties.' };
```
``` js
//
// BAD
//
callback({
message: 'I have no call-stack no interesting properties.'
});
```
**[[⬆]](#table-of-contents)**
## Exports
- **RULE**: If you are exporting something, it **should** be exported on the same line as the declaration.
> Makes it easier to understand what the exports are immediately in the same context.
``` js
//
// GOOD
//
var Foo = exports.Foo = function () {
//...
};
```
``` js
//
// BAD
//
var Foo = function () {
//...
};
//
// Lots of other code changing my mental context
// by the time I see Foo again I forgot what it was.
//
exports.Foo = Foo;
```
**[[⬆]](#table-of-contents)**
## Async Programming
- **RULE**: You **must not** use promises.
- **RULE**: You **must** use [async](https://github.com/caolan/async).
> Just use async. If you love promises then sorry; this decision
> is final and _not up for debate_ **_… ever._**
``` js
//
// GOOD
//
var async = require('async');
```
``` js
//
// BAD
//
var Q = require('q');
```
<hr>
- **RULE**: A given function **must not** have more than **three** callback functions.
> Rule of three. What? It works in fairy tales.
> INSERT CODE EXAMPLES HERE
- **RULE**: Named functions **should** be preferred over anonymous inline functions.
**[[⬆]](#table-of-contents)**
### Attribution (with modifications and additions)
* https://github.com/cloudhead/styleguide/blob/master/JavaScript.md
* https://github.com/airbnb/javascript
نیازمندی
| مقدار | نام |
|---|---|
| ^3.2.1 | fashion-show |
| ^2.1.1 | jscs |
| ^2.8.0 | jshint |
زبان مورد نیاز
| مقدار | نام |
|---|---|
| 0.10.38 | Npm |
نحوه نصب
نصب پکیج tgz common-style-3.1.0:
npm install common-style-3.1.0.tgz