Class: RuboCop::Cop::Style::IdenticalConditionalBranches

Inherits:
Base
  • Object
show all
Extended by:
AutoCorrector
Includes:
RangeHelp
Defined in:
lib/rubocop/cop/style/identical_conditional_branches.rb

Overview

Checks for identical expressions at the beginning or end of each branch of a conditional expression. Such expressions should normally be placed outside the conditional expression - before or after it.

Note
The cop is poorly named and some people might think that it actually checks for duplicated conditional branches. The name will probably be changed in a future major RuboCop release.

Examples:

# bad
if condition
  do_x
  do_z
else
  do_y
  do_z
end

# good
if condition
  do_x
else
  do_y
end
do_z

# bad
if condition
  do_z
  do_x
else
  do_z
  do_y
end

# good
do_z
if condition
  do_x
else
  do_y
end

# bad
case foo
when 1
  do_x
when 2
  do_x
else
  do_x
end

# good
case foo
when 1
  do_x
  do_y
when 2
  # nothing
else
  do_x
  do_z
end

# bad
case foo
in 1
  do_x
in 2
  do_x
else
  do_x
end

# good
case foo
in 1
  do_x
  do_y
in 2
  # nothing
else
  do_x
  do_z
end

Cop Safety Information:

  • Autocorrection is unsafe because changing the order of method invocations may change the behavior of the code. For example:

    if method_that_modifies_global_state # 1
      method_that_relies_on_global_state # 2
      foo                                # 3
    else
      method_that_relies_on_global_state # 2
      bar                                # 3
    end

    In this example, method_that_relies_on_global_state will be moved before method_that_modifies_global_state, which changes the behavior of the program.

Constant Summary collapse

MSG =
'Move `%<source>s` out of the conditional.'

Constants inherited from Base

Base::RESTRICT_ON_SEND

Instance Attribute Summary

Attributes inherited from Base

#config, #processed_source

Instance Method Summary collapse

Methods included from AutoCorrector

support_autocorrect?

Methods inherited from Base

#active_support_extensions_enabled?, #add_global_offense, #add_offense, autocorrect_incompatible_with, badge, #begin_investigation, callbacks_needed, #callbacks_needed, #config_to_allow_offenses, #config_to_allow_offenses=, #cop_config, cop_name, #cop_name, department, documentation_url, exclude_from_registry, #excluded_file?, #external_dependency_checksum, inherited, #initialize, #inspect, joining_forces, lint?, match?, #offenses, #on_investigation_end, #on_new_investigation, #on_other_file, #parse, #ready, #relevant_file?, support_autocorrect?, support_multiple_source?, #target_rails_version, #target_ruby_version

Methods included from ExcludeLimit

#exclude_limit

Methods included from AutocorrectLogic

#autocorrect?, #autocorrect_enabled?, #autocorrect_requested?, #autocorrect_with_disable_uncorrectable?, #correctable?, #disable_uncorrectable?, #safe_autocorrect?

Methods included from IgnoredNode

#ignore_node, #ignored_node?, #part_of_ignored_node?

Methods included from Util

silence_warnings

Constructor Details

This class inherits a constructor from RuboCop::Cop::Base

Instance Method Details

#on_case(node) ⇒ Object



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# File 'lib/rubocop/cop/style/identical_conditional_branches.rb', line 123

def on_case(node)
  return unless node.else? && node.else_branch

  branches = node.when_branches.map(&:body).push(node.else_branch)
  check_branches(node, branches)
end

#on_case_match(node) ⇒ Object



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# File 'lib/rubocop/cop/style/identical_conditional_branches.rb', line 130

def on_case_match(node)
  return unless node.else? && node.else_branch

  branches = node.in_pattern_branches.map(&:body).push(node.else_branch)
  check_branches(node, branches)
end

#on_if(node) ⇒ Object



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# File 'lib/rubocop/cop/style/identical_conditional_branches.rb', line 116

def on_if(node)
  return if node.elsif?

  branches = expand_elses(node.else_branch).unshift(node.if_branch)
  check_branches(node, branches)
end