class RuboCop::Cop::Style::StringHashKeys

{ one: 1, two: 2, three: 3 }
# good
{ ‘one’ => 1, ‘two’ => 2, ‘three’ => 3 }
# bad
@example
there are instances when string keys are required.
This cop is unsafe because while symbols are preferred for hash keys,
@safety
symbols is preferred instead.
Checks for the use of strings as keys in hashes. The use of

def on_pair(node) 

def on_pair(node)
  return unless string_hash_key?(node)
  key_content = node.key.str_content
  return unless key_content.valid_encoding?
  return if receive_environments_method?(node)
  add_offense(node.key) do |corrector|
    symbol_content = key_content.to_sym.inspect
    corrector.replace(node.key, symbol_content)
  end
end