class RuboCop::Cop::Style::HashLikeCase

Checks for places where ‘case-when` represents a simple 1:1 mapping and can be replaced with a hash lookup.

@example MinBranchesCount: 3 (default)

# bad
case country
when 'europe'
  'http://eu.example.com'
when 'america'
  'http://us.example.com'
when 'australia'
  'http://au.example.com'
end

# good
SITES = {
  'europe'    => 'http://eu.example.com',
  'america'   => 'http://us.example.com',
  'australia' => 'http://au.example.com'
}
SITES[country]

@example MinBranchesCount: 4

# good
case country
when 'europe'
  'http://eu.example.com'
when 'america'
  'http://us.example.com'
when 'australia'
  'http://au.example.com'
end

Constants

MSG

Public Instance Methods

on_case(node) click to toggle source
# File lib/rubocop/cop/style/hash_like_case.rb, line 51
def on_case(node)
  return if node.when_branches.size < min_branches_count

  hash_like_case?(node) do |condition_nodes, body_nodes|
    if nodes_of_same_type?(condition_nodes) && nodes_of_same_type?(body_nodes)
      add_offense(node)
    end
  end
end

Private Instance Methods

min_branches_count() click to toggle source
# File lib/rubocop/cop/style/hash_like_case.rb, line 67
def min_branches_count
  length = cop_config['MinBranchesCount'] || 3
  return length if length.is_a?(Integer) && length.positive?

  warn Rainbow('`MinBranchesCount` needs to be a positive integer!').red
  exit!
end
nodes_of_same_type?(nodes) click to toggle source
# File lib/rubocop/cop/style/hash_like_case.rb, line 63
def nodes_of_same_type?(nodes)
  nodes.all? { |node| node.type == nodes.first.type }
end