Class: RuboCop::Cop::Style::EmptyStringInsideInterpolation

# File 'lib/rubocop/cop/style/empty_string_inside_interpolation.rb', line 109

def command_call?(node)
  return false unless node.type?(:call, :super, :yield) && node.arguments?
  return false if node.call_type? && (node.operator_method? || node.setter_method?)

  !node.parenthesized?
end

# File 'lib/rubocop/cop/style/empty_string_inside_interpolation.rb', line 124

def empty_branch_outcome?(branch)
  return false unless branch

  branch.nil_type? || (branch.str_type? && branch.value.empty?)
end

# File 'lib/rubocop/cop/style/empty_string_inside_interpolation.rb', line 120

def empty_else_outcome?(node)
  empty_branch_outcome?(node.else_branch)
end

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

def empty_if_outcome?(node)
  empty_branch_outcome?(node.if_branch)
end

# File 'lib/rubocop/cop/style/empty_string_inside_interpolation.rb', line 142

def empty_string_conditional_in_condition?(if_node)
  if_node.condition.each_descendant(:if).any? do |node|
    next false if node.modifier_form? || !node.parent.parent&.type?(*INTERPOLATED_TYPES)

    empty_if_outcome?(node) || empty_else_outcome?(node)
  end
end

# File 'lib/rubocop/cop/style/empty_string_inside_interpolation.rb', line 86

def nested_trailing_conditional?(if_node)
  if_node.each_descendant(:if).any? do |node|
    node.modifier_form? && node.parent.parent&.type?(*INTERPOLATED_TYPES)
  end
end

# File 'lib/rubocop/cop/style/empty_string_inside_interpolation.rb', line 50

def on_interpolation(node)
  node.each_child_node(:if) do |child_node|
    if style == :trailing_conditional
      trailing_conditional_correction(child_node)
    elsif style == :ternary
      ternary_correction(node, child_node)
    end
  end
end

# File 'lib/rubocop/cop/style/empty_string_inside_interpolation.rb', line 100

def ternary_branch_source(branch)
  return branch.source unless command_call?(branch)

  arguments = branch.first_argument.source_range.join(branch.last_argument.source_range)
  method = branch.source_range.begin.join(arguments.begin).source.rstrip

  "#{method}(#{arguments.source})"
end

# File 'lib/rubocop/cop/style/empty_string_inside_interpolation.rb', line 76

def ternary_correction(node, child_node)
  return unless child_node.modifier_form?

  add_offense(node, message: MSG_TRAILING_CONDITIONAL) do |corrector|
    next if nested_trailing_conditional?(child_node)

    autocorrect_to_ternary(corrector, child_node)
  end
end

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

def ternary_style_autocorrect(node, outcome, keyword)
  add_offense(node, message: MSG_TERNARY) do |corrector|
    next if empty_string_conditional_in_condition?(node)

    head = node.source_range.begin.join(outcome.source_range.begin)
    tail = outcome.source_range.end.join(node.source_range.end)

    corrector.remove(head)
    corrector.replace(tail, " #{keyword} #{node.condition.source}")
  end
end

# File 'lib/rubocop/cop/style/empty_string_inside_interpolation.rb', line 62

def trailing_conditional_correction(child_node)
  # A modifier `if`/`unless` is already a trailing conditional and has
  # no `else` branch, so the ternary-to-trailing rewrite does not apply.
  return if child_node.modifier_form?

  if empty_if_outcome?(child_node)
    ternary_style_autocorrect(child_node, child_node.else_branch, 'unless')
  end

  return unless empty_else_outcome?(child_node)

  ternary_style_autocorrect(child_node, child_node.if_branch, 'if')
end