class RuboCop::Cop::Style::GuardClause

ok
raise ‘exception’ if something
# good
end
ok
else
raise ‘exception’
if something
# bad
end
work if something
def test
# also good
end
work
return unless something
def test
# good
end
end
work
if something
def test
# bad
@example
expression
Use a guard clause instead of wrapping the code inside a conditional

def accepted_form?(node, ending = false) 

def accepted_form?(node, ending = false)
  accepted_if?(node, ending) || node.condition.multiline?
end

def accepted_if?(node, ending) 

def accepted_if?(node, ending)
  return true if node.modifier_form? || node.ternary?
  if ending
    node.else?
  else
    !node.else? || node.elsif?
  end
end

def check_ending_if(node) 

def check_ending_if(node)
  return if accepted_form?(node, true) || !min_body_length?(node)
  add_offense(node, location: :keyword)
end

def contains_guard_clause?(node) 

def contains_guard_clause?(node)
  node.if_branch && node.if_branch.guard_clause? ||
    node.else_branch && node.else_branch.guard_clause?
end

def on_def(node) 

def on_def(node)
  body = node.body
  return unless body
  if body.if_type?
    check_ending_if(body)
  elsif body.begin_type? && body.children.last.if_type?
    check_ending_if(body.children.last)
  end
end

def on_if(node) 

def on_if(node)
  return if accepted_form?(node) || !contains_guard_clause?(node)
  add_offense(node, location: :keyword)
end