class RuboCop::Cop::Lint::DuplicateBranch
Checks that there are no repeated bodies within ‘if/unless`, `case-when`, `case-in` and `rescue` constructs.
With ‘IgnoreLiteralBranches: true`, branches are not registered as offenses if they return a basic literal value (string, symbol, integer, float, rational, complex, `true`, `false`, or `nil`), or return an array, hash, regexp or range that only contains one of the above basic literal values.
With ‘IgnoreConstantBranches: true`, branches are not registered as offenses if they return a constant value.
With ‘IgnoreDuplicateElseBranch: true`, in conditionals with multiple branches, duplicate ’else’ branches are not registered as offenses.
@example
# bad if foo do_foo do_something_else elsif bar do_foo do_something_else end # good if foo || bar do_foo do_something_else end # bad case x when foo do_foo when bar do_foo else do_something_else end # good case x when foo, bar do_foo else do_something_else end # bad begin do_something rescue FooError handle_error rescue BarError handle_error end # good begin do_something rescue FooError, BarError handle_error end
@example IgnoreLiteralBranches: true
# good case size when "small" then 100 when "medium" then 250 when "large" then 1000 else 250 end
@example IgnoreConstantBranches: true
# good case size when "small" then SMALL_SIZE when "medium" then MEDIUM_SIZE when "large" then LARGE_SIZE else MEDIUM_SIZE end
@example IgnoreDuplicateElseBranch: true
# good if foo do_foo elsif bar do_bar else do_foo end
Constants
- MSG
Public Instance Methods
# File lib/rubocop/cop/lint/duplicate_branch.rb, line 102 def on_branching_statement(node) branches = branches(node) branches.each_with_object(Set.new) do |branch, previous| next unless consider_branch?(branches, branch) add_offense(offense_range(branch)) unless previous.add?(branch) end end
# File lib/rubocop/cop/lint/duplicate_branch.rb, line 114 def on_if(node) # Ignore 'elsif' nodes, because we don't want to check them separately whether # the 'else' branch is duplicated. We want to check only on the outermost conditional. on_branching_statement(node) unless node.elsif? end
Private Instance Methods
# File lib/rubocop/cop/lint/duplicate_branch.rb, line 136 def branches(node) node.branches.compact end
# File lib/rubocop/cop/lint/duplicate_branch.rb, line 140 def consider_branch?(branches, branch) return false if ignore_literal_branches? && literal_branch?(branch) return false if ignore_constant_branches? && const_branch?(branch) if ignore_duplicate_else_branches? && duplicate_else_branch?(branches, branch) return false end true end
# File lib/rubocop/cop/lint/duplicate_branch.rb, line 174 def const_branch?(branch) branch.const_type? end
# File lib/rubocop/cop/lint/duplicate_branch.rb, line 178 def duplicate_else_branch?(branches, branch) return false unless (parent = branch.parent) branches.size > 2 && branch.equal?(branches.last) && parent.respond_to?(:else?) && parent.else? end
# File lib/rubocop/cop/lint/duplicate_branch.rb, line 155 def ignore_constant_branches? cop_config.fetch('IgnoreConstantBranches', false) end
# File lib/rubocop/cop/lint/duplicate_branch.rb, line 159 def ignore_duplicate_else_branches? cop_config.fetch('IgnoreDuplicateElseBranch', false) end
# File lib/rubocop/cop/lint/duplicate_branch.rb, line 151 def ignore_literal_branches? cop_config.fetch('IgnoreLiteralBranches', false) end
# File lib/rubocop/cop/lint/duplicate_branch.rb, line 163 def literal_branch?(branch) # rubocop:disable Metrics/CyclomaticComplexity return false if !branch.literal? || branch.xstr_type? return true if branch.basic_literal? branch.each_descendant.all? do |node| node.basic_literal? || node.pair_type? || # hash keys and values are contained within a `pair` node (node.const_type? && ignore_constant_branches?) end end
# File lib/rubocop/cop/lint/duplicate_branch.rb, line 122 def offense_range(duplicate_branch) parent = duplicate_branch.parent if parent.respond_to?(:else_branch) && parent.else_branch.equal?(duplicate_branch) if parent.if_type? && parent.ternary? duplicate_branch.source_range else parent.loc.else end else parent.source_range end end