Tagview Coffeescript Style Guide

White Space

Use soft tabs with 2 spaces.

# Bad
hello = (names) ->
∙∙∙∙for name in names
∙∙∙∙∙∙∙∙alert name

hello = (names) ->
∙for name in names
∙∙alert name

# Good
hello = (names) ->
∙∙for name in names
∙∙∙∙alert name

Don't put spaces between parentheses.

# Bad
triangle = ( base, height ) -> base * height / 2

# Good
triangle = (base, height) -> base * height / 2

Put a space after a comma and operator signs.

# Bad
user = new User "Bruce","Lee"
numbers = [1,2,3]
sum = 1+2

# Good
user = new User "Bruce", "Lee"
numbers = [1, 2, 3]
sum = 1 + 2

Put a space after an assignment.

# Bad
hello = (name="Joe") -> alert "Hello #{name}"

# Good
hello = (name = "Joe") -> alert "Hello #{name}"

Don't put spaces before :.

# Bad
user = 
  name : "Sasha"
  age : 25

# Good
user = 
  name: "Sasha"
  age: 25

Naming

Use camelCase for objects, functions and primitives.

# Bad
User = name: "Sasha"
check-power-level = -> "Over 9 thousands"
powerfull_user = name: "Vegeta"
power_level = 9000

# Good
user = name: "Sasha"
checkPowerLevel -> "Over 9 thousands"
powerfullUser = name: "Vegeta"
powerLevel = 9000

Use PascalCase for classes.

# Bad
class user extends human
  constructor: (@name) ->

bad = new user "Noooooo"

# Good
class User extends Human
  constructor: (@name) ->

good = new User "Yeah"

Use uppercase with underscores for constants.

HI_I_AM_A_CONSTANT = 42

Prefix jQuery/zeptojs objects with a $.

# Bad
header = $(".header")

# Good
$header = $(".header")

Prefix booleans with is or has.

user.isActive
user.hasPosts()

Strings

Use double "" quotes.

# Bad
name = 'Vegeta'

# Good
name = "Vegeta"

Use interpolation instead of contatenation.

# Bad
"Hello " + name + ", how are you?"

# Good
"Hello #{name}, how are you?"

Arrays

Always use array literals.

# Bad
names = new Array

# Good
names = []

When you need to transform an array-like object into an array, use Array#slice.

test = ->
  args = Array::slice.apply(arguments)

Objects

Always use object literals.

# Bad
obj = new Object

# Good
obj = {}

Don't use strings as keys.

# Bad
var obj = 
  "name": "Sasha"
  "age": 23

# Good
var obj =
  name: "Sasha"
  age: 23

Don't use commas when creating multiline objects.

# Bad
var obj = 
  name: "Sasha",
  age: 23,
  rating: 10

# Good
var obj = 
  name: "Sasha"
  age: 23
  rating: 10

When possible, don't use the braces.

# Bad
triangle = new Triangle({ base: 10, height: 30})
triangle = new Triangle { base: 10, height: 30}

# Good
triangle = new Triangle(base: 10, height: 30)
triangle = new Triangle base: 10, height: 30

Functions

Don't use parentheses when declaring functions that take no arguments.

# Bad
hello = () -> alert "Hello"

# Good
hello = -> alert "Hello"

When the function has arguments, put a space after the parentheses.

# Bad
hello = (name)-> alert "Hello #{name}"

# Good
hello = (name) -> alert "Hello #{name}"

Classes and Constructor Functions

Don't open the parentheses when creating objects from classes that don't accept arguments.

# Bad
user = new User()

# Good
user = new User

Use :: to access the function prototype.

# Bad
Array.prototype.slice([1, 2])

# Good
Array::slice([1, 2])

Prefer @ over this.property.

# Bad
class User
  fullName: ->
    this.firstName + this.lastName

# Good
class User
  fullName: ->
    @firstName + @lastName

Avoid the use of a standalone @.

# Bad
class UsersView extends Backbone.View
  initiliaze: ->
    @collection.on "reset", @render, @

  render: ->
    $("body").html("Hi")
    @

# Good
class UsersView extends Backbone.View
  initiliaze: ->
    @collection.on "reset", @render, this

  render: ->
    $("body").html("Hi")
    this

Try to avoid to use the fat arrow => when declaring methods, as it can impact performance in some cases.

# Bad
class UserView extends Backbone.View
  initialize: ->
    @collection.on "reset", @render

  render: =>
    ...

# Good
class UserView extends Backbone.View
  initialize: ->
    @collection.on "reset", @render, this

  render: ->
    ...

Conditionals

Don't use unless...else, use if...else

# Bad
unless isLogged
  login()
else
  "Hello"

# Good
if isLogged
  "Hello"
else
  login()

Comments

Always put a newline above a comment.

# Bad
isActive = true
# The admin
user = new Admin

# Good
isActive = true

# The admin
user = new Admin

When using multiline comments, use a empty # to separate paragraphs.

# This is a block comment. Note that if this were a real block
# comment, we would actually be describing the proceeding code.
#
# This is the second paragraph of the same block comment. Note
# that this paragraph was separated from the previous paragraph
# by a line containing a single comment character.

Semicolons

Nope

# Bad
user = new User;

# Good
user = new User

lpelos / coffeescript-style-guide