.rubocop.yml

AllCops:
  # Cache the results for faster processing
  UseCache: true
  # Show the name of the cops being voilated in the feedback
  DisplayCopNames: true
  DisplayStyleGuide: true
  # We're using Ruby 2.4 right now. So force that version or higher.
  TargetRubyVersion: 2.4
  # Don't check these files. So many of them are boilerplate code with violations.
  Exclude:
    - 'bin/*'
    - 'lib/tasks/**/*'
    - 'Gemfile'
    - 'db/**/*'
    - 'config/**/*'
    - 'script/**/*'
    - '**/Rakefile'
    - '**/config.ru'

# Ignore this cop. The Rubocop default is sensible, but the rubocop-rails gem modifies
# this to position end keywords awkwardly.
Layout/EndAlignment:
  Enabled: true
  EnforcedStyleAlignWith: keyword

# Force no empty lines at the start or end of a block's body. Ignore specs, since this
# improves readability within the RSpec blocks.
Layout/EmptyLinesAroundBlockBody:
  Exclude:
    - 'spec/**/*'

# Force a single blank line around a class's body. Adding this whitespace makes code
# a bit easier to read.
Layout/EmptyLinesAroundClassBody:
  Enabled: true
  EnforcedStyle: empty_lines

# Force a single blank line around a module's body. Adding this whitespace makes code
# a bit easier to read.
Layout/EmptyLinesAroundModuleBody:
  Enabled: true
  EnforcedStyle: empty_lines

Layout/IndentationWidth:
  Description: 'Use 2 spaces for indentation.'
  StyleGuide: '#spaces-indentation'
  Enabled: true

# The difference between `rails` and `normal` is that the `rails` style
# prescribes that in classes and modules the `protected` and `private`
# modifier keywords shall be indented the same as public methods and that
# protected and private members shall be indented one step more than the
# modifiers. Other than that, both styles mean that entities on the same
# logical depth shall have the same indentation.
Layout/IndentationConsistency:
  Description: 'Keep indentation straight.'
  StyleGuide: '#spaces-indentation'
  Enabled: true
  EnforcedStyle: normal

# Enforce this in the main code but ignore it in specs since the Rspec core methods
# are defined as potentially ambiguous blocks
Lint/AmbiguousBlockAssociation:
  Exclude:
    - 'spec/**/*'

# Restrict the length of each line of code to 90 characters. Enforcing this is important
# as many developers are working on smaller screens, or split screens. Having to scroll
# to read a full line of code makes code harder to read and more frustrating to work with.
Metrics/LineLength:
  # I've found that 90 is a suitable limit. Many developers balk at the 80 character
  # default.
  Max: 90
  Exclude:
    # Excludes the spec helper, since this boilerplate file has comments that are much
    # longer.
    - 'spec/spec_helper.rb'

# Restrict the number of lines of code that may be within a block of code. This should
# force developers to break their code into smaller discrete methods or objects.
Metrics/BlockLength:
  # Exclude specs, since those are defined as large blocks of code
  Exclude:
    - 'spec/**/*'

# This cop enforces the use of boolean and/or "&&" and "||" over "and" "or".
# Sometimes using "and"/"or" is preferrable, when these are used as control flow.
#
# For example:
#
#   render text: "Hello world" and return
#
Style/AndOr:
  Enabled: false

# This cop enforces how modules and classes are nested within another module or class.
# In Rails code (e.g. models and controllers) nesting with a colon is preferrable (e.g.
# User::Session).
Style/ClassAndModuleChildren:
  Exclude:
    - 'app/**/*'

# This cop enforces each class to have documentation at the top. That's not always
# practical or necessary in Rails apps (e.g. the purpose of helpers is self evident).
Style/Documentation:
  Enabled: false

# Enforce double quotes. Don't allow single quotes. This is preferred since double
# quotes are more useful (they support escaping characters, and interpolation).
Style/StringLiterals:
  Enabled: true
  EnforcedStyle: double_quotes

# Enforce empty methods to be written across two lines, like any normal method would be.
# This allows for easy modification of the method in future.
Style/EmptyMethod:
  Enabled: true
  EnforcedStyle: expanded