style

Style

A guide for programming in style.

Git

• Avoid merge commits by using a rebase workflow.
• Prefix feature branch names with your initials.
• Squash multiple trivial commits into a single commit.
• Write a good commit message.

Formatting

• Avoid inline comments.
• Break long lines after 80 characters.
• Delete trailing whitespace.
• Don't include spaces after (, [ or before ], ).
• Don't misspell.
• Don't vertically align tokens on consecutive lines.
• If you break up an argument list, keep the arguments on their own lines and closing parenthesis on its own line.
• If you break up a hash, keep the elements on their own lines and closing curly brace on its own line.
• Indent continued lines two spaces.
• Indent private methods equal to public methods.
• Use 2 space indentation (no tabs).
• Use an empty line between methods.
• Use newlines around multi-line blocks.
• Use spaces around operators, after commas, after colons and semicolons, around { and before }.
• Use Unix-style line endings (\n).
• Use uppercase for SQL key words and lowercase for SQL identifiers.

Naming

• Avoid abbreviations.
• Avoid types in names (user_array).
• Name the enumeration parameter the singular of the collection.
• Name variables, methods, and classes to reveal intent.
• Treat acronyms as words in names (XmlHttpRequest not XMLHTTPRequest), even if the acronym is the entire name (class Html not class HTML).
• Name variables holding a factory with _factory (user_factory).
• Name variables created by a factory after the factory (user_factory creates user).

Organization

• Order methods so that caller methods are earlier in the file than the methods they call.
• Order methods so that methods are as close as possible to other methods they call.

Sass

Formatting

• Use the Scss syntax.
• Use hyphens when naming mixins, extends, classes, functions & variables: span-columns not span_columns or spanColumns.
• Use space between property and value: width: 20px not width:20px.
• Use a blank line above selector that has styles.
• Prefer hex color codes #000.
• Use // for comment blocks not /* */.
• Use a space between selector and {.
• Use single quotation marks for attribute selectors and property values.
• Use only lowercase, including colors.
• Don't add a unit specification after 0 values, unless required by a mixin.

Order

• Use alphabetical order for declarations.
• Place @extends and @includes at the top of your declaration list.
• Place media queries directly after the declaration list.
• Place concatenated selectors second.
• Place pseudo states and elements third.
• Place nested selectors last.

Selectors

• Don't use ID's for style.
• Use meaningful names: $visual-grid-color not $color or $vslgrd-clr.
• Use ID and class names that are as short as possible but as long as necessary.
• Append the prefix js- to ID's that are used by Javascript.
• Avoid using the direct descendant selector >.
• Avoid nesting more than 4 selectors deep.
• Don't nest more than 6 selectors deep.
• Use HTML tags on vague classes that need a qualifier like header.application not .main.
• Avoid using the HTML tag in the class name: section.news not section.news-section.
• Avoid using HTML tags on classes for generic markup <div>, <span>: .widgets not div.widgets.
• Avoid using HTML tags on classes with specific class names like .featured-articles.
• Avoid using comma delimited selectors.
• Avoid nesting within a media query.

Organization

• Use Bourbon for a Sass Library.
• Use Neat for a grid framework.
• Use Bitters / Base folder for style on HTML tags, global variables, global extends and global mixins.
• Use Normalize as a browser reset.
• Use HTML structure for ordering of selectors. Don't just put styles at the bottom of the Sass file.
• Prefer the same file structure that is found in app/views.
• Avoid having files longer than 100 lines.

CoffeeScript

• Initialize arrays using [].
• Initialize empty objects and hashes using {}.
• Use CamelCase for classes, lowerCamelCase for variables and functions, SCREAMING_SNAKE_CASE for constants, _single_leading_underscore for private variables and functions.
• Prefer is to == or ===
• Prefer or and and to || and &&

Ruby

Sample

• Avoid conditional modifiers (lines that end with conditionals).
• Avoid multiple assignments per line (one, two = 1, 2).
• Avoid organizational comments (# Validations).
• Avoid ternary operators (boolean ? true : false). Use multi-line if instead to emphasize code branches.
• Avoid explicit return statements.
• Avoid using semicolons.
• Don't use self explicitly anywhere except class methods (def self.method) and assignments (self.attribute =).
• Prefer detect over find.
• Prefer inject over reduce.
• Prefer map over collect.
• Prefer select over find_all.
• Prefer single quotes for strings.
• Use _ for unused block parameters.
• Use %{} for single-line strings needing interpolation and double-quotes.
• Use && and || for Boolean expressions.
• Use {...} for single-line blocks. Use do..end for multi-line blocks.
• Use ? suffix for predicate methods.
• Use CamelCase for classes and modules, snake_case for variables and methods, SCREAMING_SNAKE_CASE for constants.
• Use def self.method, not def Class.method or class << self.
• Use def with parentheses when there are arguments.
• Use each, not for, for iteration.
• Use heredocs for multi-line strings.

ERb

Sample

• When wrapping long lines, keep the method name on the same line as the ERb interpolation operator and keep each method argument on its own line.
• Prefer double quotes for attributes.

HTML

• Prefer double quotes for attributes.

Rails

• Avoid member and collection routes.
• Use private instead of protected when defining controller methods.
• Name date columns with _on suffixes.
• Name datetime columns with _at suffixes.
• Name initializers for their gem name.
• Order ActiveRecord associations alphabetically by attribute name.
• Order ActiveRecord validations alphabetically by attribute name.
• Order controller contents: filters, public methods, private methods.
• Order model contents: constants, macros, public methods, private methods.
• Put application-wide partials in the app/views/application directory.
• Use def self.method, not the scope :method DSL.
• Use the default render 'partial' syntax over render partial: 'partial'.

Rails Routes

• Avoid the :except option in routes.
• Order resourceful routes alphabetically by name.
• Use the :only option to explicitly state exposed routes.

Background Jobs

• Define a PRIORITY constant at the top of delayed job classes.
• Define two public methods: self.enqueue and perform.
• Put delayed job classes in app/jobs.

Email

• Use one ActionMailer for the app. Name it Mailer.
• Use the user's name in the From header and email in the Reply-To when delivering email on behalf of the app's users.

Testing

• Avoid the private keyword in specs.
• Order ActiveRecord association tests alphabetically by attribute name.
• Order ActiveRecord validation tests alphabetically by attribute name.
• Prefer eq to == in RSpec.
• Separate setup, exercise, verification, and teardown phases with newlines.
• Use RSpec's expect syntax.
• Use not_to instead of to_not in RSpec expectations.

Acceptance Tests

Sample

• Avoid scenario titles that add no information, such as "successfully."
• Avoid scenario titles that repeat the feature title.
• Place helper methods for feature specs directly in a top-level Features module.
• Use Capybara's feature/scenario DSL.
• Use names like ROLE_ACTION_spec.rb, such as user_changes_password_spec.rb, for feature spec file names.
• Use only one feature block per feature spec file.
• Use scenario titles that describe the success and failure paths.
• Use spec/features directory to store feature specs.
• Use spec/support/features for support code related to feature specs.

Factories

• Order factories.rb contents: sequences, traits, factory definitions.
• Order factory attributes: implicit attributes, explicit attributes, child factory definitions. Each section's attributes are alphabetical.
• Order factory definitions alphabetically by factory name.
• Use one factories.rb file per project.

Unit Tests

Sample

• Don't prefix it block descriptions with 'should'.
• Name outer describe blocks after the method under test. Use .method for class methods and #method for instance methods.

Objective-C

Sample

• #import linked frameworks in the prefix header (ProjectName-Prefix.pch).
• Keep .xib files grouped with their associated view class.
• Order #import statements alphabetically.
• Order @class directives alphabetically.
• Order @property modifiers: memory management, atomicity, writability.
• Organize classes into models, views, controllers, categories, and services directories.
• Prefer @class to #import when referring to external classes in a public @interface.
• Prefer @property to declaring instance variables.
• Prefix class names with a 2 or 3 letter project acronym.
• Prefix string constants being used as keys with 'k'.
• Remove #import statements for Foundation and UIKit in new project templates.
• Separate methods by function using #pragma mark - <Section Name>
• Separate sections into subsections using #pragma mark <Subsection Name>
• Use @[arrayObject], @{@"key" : value}, @(YES or NO), and @5.0 literals.
• Use @interface ClassName () to declare private properties.
• Use lowerCamelCase for method names.
• Use NSAssert in methods that require the presence of certain arguments.
• Write methods using the happy path. Indent the exceptional cases. Keep the optimal case in the left-most column.

Python

• Follow PEP 8.