class RuboCop::Cop::Style::MapCompactWithConditionalBlock


array.reject { |e| some_condition? }
# good
array.select { |e| some_condition? }
# good
end.compact
e if some_condition?
array.map do |e|
# bad
end.compact
e
next if some_condition?
array.map do |e|
# bad
end.compact
end
next
else
e
if some_condition?
array.map do |e|
# bad
array.filter_map { |e| some_condition? ? e : next }
# bad
array.map { |e| some_condition? ? e : next }.compact
# bad
@example
This cop also handles ‘filter_map { … }`, similar to `map { … }.compact`.
Prefer `select` or `reject` over `map { … }.compact`.

def current(node) 

def current(node)
  if node.method?(:compact)
    map_or_filter_map_method = node.children.first
    "#{map_or_filter_map_method.method_name} { ... }.compact"
  else
    'filter_map { ... }'
  end
end

def filter_map_range(node) 

def filter_map_range(node)
  node.loc.selector.join(node.parent.source_range.end)
end

def inspect(node, block_argument_node, condition_node, return_value_node, range) 

def inspect(node, block_argument_node, condition_node, return_value_node, range)
  return unless returns_block_argument?(block_argument_node, return_value_node)
  return if condition_node.parent.elsif?
  method = truthy_branch?(return_value_node) ? 'select' : 'reject'
  current = current(node)
  add_offense(range, message: format(MSG, current: current, method: method)) do |corrector|
    return if part_of_ignored_node?(node) || ignored_node?(node)
    corrector.replace(
      range, "#{method} { |#{block_argument_node.source}| #{condition_node.source} }"
    )
    ignore_node(node)
  end
end

def map_with_compact_range(node) 

def map_with_compact_range(node)
  node.receiver.send_node.loc.selector.begin.join(node.source_range.end)
end

def on_send(node) 

def on_send(node)
  map_candidate = node.children.first
  if (block_argument, condition, return_value = conditional_block(map_candidate))
    return unless node.method?(:compact) && node.arguments.empty?
    range = map_with_compact_range(node)
  elsif (block_argument, condition, return_value = conditional_block(node.parent))
    return unless node.method?(:filter_map)
    range = filter_map_range(node)
  else
    return
  end
  inspect(node, block_argument, condition, return_value, range)
end

def returns_block_argument?(block_argument_node, return_value_node) 

def returns_block_argument?(block_argument_node, return_value_node)
  block_argument_node.name == return_value_node.children.first
end

def truthy_branch?(node) 

def truthy_branch?(node)
  if node.parent.begin_type?
    truthy_branch_for_guard?(node)
  elsif node.parent.next_type?
    truthy_branch_for_if?(node.parent)
  else
    truthy_branch_for_if?(node)
  end
end

def truthy_branch_for_guard?(node) 

def truthy_branch_for_guard?(node)
  if_node = node.left_sibling
  if if_node.if?
    if_node.if_branch.arguments.any?
  else
    if_node.if_branch.arguments.none?
  end
end

def truthy_branch_for_if?(node) 

def truthy_branch_for_if?(node)
  if_node = node.parent
  if if_node.if? || if_node.ternary?
    if_node.if_branch == node
  elsif if_node.unless?
    if_node.else_branch == node
  end
end