class RuboCop::Cop::Style::ConditionalAssignment
Check for ‘if` and `case` statements where each branch is used for assignment to the same variable when using the return of the condition can be used instead.
@example EnforcedStyle: assign_to_condition (default)
# bad if foo bar = 1 else bar = 2 end case foo when 'a' bar += 1 else bar += 2 end if foo some_method bar = 1 else some_other_method bar = 2 end # good bar = if foo 1 else 2 end bar += case foo when 'a' 1 else 2 end bar << if foo some_method 1 else some_other_method 2 end
@example EnforcedStyle: assign_inside_condition
# bad bar = if foo 1 else 2 end bar += case foo when 'a' 1 else 2 end bar << if foo some_method 1 else some_other_method 2 end # good if foo bar = 1 else bar = 2 end case foo when 'a' bar += 1 else bar += 2 end if foo some_method bar = 1 else some_other_method bar = 2 end
Constants
- ASSIGNMENT_TYPES
- ASSIGN_TO_CONDITION_MSG
- ENABLED
- INDENTATION_WIDTH
- LINE_LENGTH
- MAX
- MSG
- SINGLE_LINE_CONDITIONS_ONLY
- VARIABLE_ASSIGNMENT_TYPES
- WIDTH
Public Instance Methods
on_case(node)
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# File lib/rubocop/cop/style/conditional_assignment.rb, line 266 def on_case(node) return unless style == :assign_to_condition return unless node.else_branch when_branches = expand_when_branches(node.when_branches) branches = [*when_branches, node.else_branch] check_node(node, branches) end
on_case_match(node)
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# File lib/rubocop/cop/style/conditional_assignment.rb, line 276 def on_case_match(node) return unless style == :assign_to_condition return unless node.else_branch in_pattern_branches = expand_when_branches(node.in_pattern_branches) branches = [*in_pattern_branches, node.else_branch] check_node(node, branches) end
on_if(node)
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# File lib/rubocop/cop/style/conditional_assignment.rb, line 252 def on_if(node) return unless style == :assign_to_condition return if node.elsif? else_branch = node.else_branch elsif_branches, else_branch = expand_elses(else_branch) return unless else_branch branches = [node.if_branch, *elsif_branches, else_branch] check_node(node, branches) end
on_send(node)
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# File lib/rubocop/cop/style/conditional_assignment.rb, line 246 def on_send(node) return unless assignment_type?(node) check_assignment_to_condition(node) end
Private Instance Methods
allowed_single_line?(branches)
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# File lib/rubocop/cop/style/conditional_assignment.rb, line 317 def allowed_single_line?(branches) single_line_conditions_only? && branches.any?(&:begin_type?) end
allowed_statements?(branches)
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# File lib/rubocop/cop/style/conditional_assignment.rb, line 388 def allowed_statements?(branches) return false unless branches.all? statements = branches.map { |branch| tail(branch) }.compact lhs_all_match?(statements) && statements.none?(&:masgn_type?) && assignment_types_match?(*statements) end
allowed_ternary?(assignment)
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# File lib/rubocop/cop/style/conditional_assignment.rb, line 313 def allowed_ternary?(assignment) assignment.if_type? && assignment.ternary? && !include_ternary? end
assignment_node(node)
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# File lib/rubocop/cop/style/conditional_assignment.rb, line 321 def assignment_node(node) *_variable, assignment = *node # ignore pseudo-assignments without rhs in for nodes return if node.parent&.for_type? assignment, = *assignment if assignment.begin_type? && assignment.children.one? assignment end
assignment_types_match?(*nodes)
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# File lib/rubocop/cop/style/conditional_assignment.rb, line 365 def assignment_types_match?(*nodes) return unless assignment_type?(nodes.first) nodes.map(&:type).uniq.one? end
autocorrect(corrector, node)
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# File lib/rubocop/cop/style/conditional_assignment.rb, line 380 def autocorrect(corrector, node) if assignment_type?(node) move_assignment_inside_condition(corrector, node) else move_assignment_outside_condition(corrector, node) end end
candidate_node?(node)
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# File lib/rubocop/cop/style/conditional_assignment.rb, line 306 def candidate_node?(node) style == :assign_inside_condition && assignment_rhs_exist?(node) end
check_assignment_to_condition(node)
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# File lib/rubocop/cop/style/conditional_assignment.rb, line 288 def check_assignment_to_condition(node) return unless candidate_node?(node) ignore_node(node) assignment = assignment_node(node) return unless candidate_condition?(assignment) _condition, *branches, else_branch = *assignment return unless else_branch return if allowed_single_line?([*branches, else_branch]) add_offense(node, message: ASSIGN_TO_CONDITION_MSG) do |corrector| autocorrect(corrector, node) end end
check_node(node, branches)
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# File lib/rubocop/cop/style/conditional_assignment.rb, line 371 def check_node(node, branches) return if allowed_ternary?(node) return unless allowed_statements?(branches) return if allowed_single_line?(branches) return if correction_exceeds_line_limit?(node, branches) add_offense(node) { |corrector| autocorrect(corrector, node) } end
correction_exceeds_line_limit?(node, branches)
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If ‘Layout/LineLength` is enabled, we do not want to introduce an offense by autocorrecting this cop. Find the max configured line length. Find the longest line of condition. Remove the assignment from lines that contain the offending assignment because after correcting, this will not be on the line anymore. Check if the length of the longest line + the length of the corrected assignment is greater than the max configured line length
# File lib/rubocop/cop/style/conditional_assignment.rb, line 404 def correction_exceeds_line_limit?(node, branches) return false unless line_length_cop_enabled? assignment = lhs(tail(branches[0])) longest_line_exceeds_line_limit?(node, assignment) end
include_ternary?()
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# File lib/rubocop/cop/style/conditional_assignment.rb, line 439 def include_ternary? cop_config['IncludeTernaryExpressions'] end
indentation_width()
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# File lib/rubocop/cop/style/conditional_assignment.rb, line 431 def indentation_width config.for_cop(INDENTATION_WIDTH)[WIDTH] || 2 end
lhs_all_match?(branches)
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# File lib/rubocop/cop/style/conditional_assignment.rb, line 358 def lhs_all_match?(branches) return true if branches.empty? first_lhs = lhs(branches.first) branches.all? { |branch| lhs(branch) == first_lhs } end
line_length_cop_enabled?()
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# File lib/rubocop/cop/style/conditional_assignment.rb, line 423 def line_length_cop_enabled? config.for_cop(LINE_LENGTH)[ENABLED] end
longest_line(node, assignment)
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# File lib/rubocop/cop/style/conditional_assignment.rb, line 416 def longest_line(node, assignment) assignment_regex = /\s*#{Regexp.escape(assignment).gsub('\ ', '\s*')}/ lines = node.source.lines.map { |line| line.chomp.sub(assignment_regex, '') } longest_line = lines.max_by(&:length) assignment + longest_line end
longest_line_exceeds_line_limit?(node, assignment)
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# File lib/rubocop/cop/style/conditional_assignment.rb, line 412 def longest_line_exceeds_line_limit?(node, assignment) longest_line(node, assignment).length > max_line_length end
max_line_length()
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# File lib/rubocop/cop/style/conditional_assignment.rb, line 427 def max_line_length config.for_cop(LINE_LENGTH)[MAX] end
move_assignment_inside_condition(corrector, node)
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# File lib/rubocop/cop/style/conditional_assignment.rb, line 342 def move_assignment_inside_condition(corrector, node) *_assignment, condition = *node if ternary_condition?(condition) TernaryCorrector.move_assignment_inside_condition(corrector, node) elsif condition.case_type? || condition.case_match_type? CaseCorrector.move_assignment_inside_condition(corrector, node) elsif condition.if_type? IfCorrector.move_assignment_inside_condition(corrector, node) end end
move_assignment_outside_condition(corrector, node)
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# File lib/rubocop/cop/style/conditional_assignment.rb, line 332 def move_assignment_outside_condition(corrector, node) if node.case_type? || node.case_match_type? CaseCorrector.correct(corrector, self, node) elsif node.ternary? TernaryCorrector.correct(corrector, node) elsif node.if? || node.unless? IfCorrector.correct(corrector, self, node) end end
single_line_conditions_only?()
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# File lib/rubocop/cop/style/conditional_assignment.rb, line 435 def single_line_conditions_only? cop_config[SINGLE_LINE_CONDITIONS_ONLY] end
ternary_condition?(node)
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# File lib/rubocop/cop/style/conditional_assignment.rb, line 354 def ternary_condition?(node) [node, node.children.first].any? { |n| n.if_type? && n.ternary? } end