Ruby object to hash

gistfile1.rb

class Foo
  attr_reader :alpha
  
  def initialize
    @alpha = 1
    @bravo = 2
  end
end

foo = Foo.new

# This works, but returns even instance variables that aren't public
foo.instance_variables.map { |x| [x.to_s.delete('@'), foo.instance_variable_get(x)] }.to_h
# > {'alpha': 1, 'bravo': 2}

# This works, but doesn't account for cases where the attribute only incidentally has the same name
foo.instance_variables.select do |x|
  foo.respond_to? x.to_s.delete('@')
end.map do |x|
  [x.to_s.delete('@'), foo.instance_variable_get(x)]
end.to_h
# > {'alpha': 1}

class Bar
  attr_reader :alpha
  attr_reader :charlie
  
  def initialize
    @alpha = 1
    @bravo = 2
    @charlie = 3
  end
  
  def charlie
    :masked_value
  end
end

bar = Bar.new

bar.instance_variables.select do |x|
  bar.respond_to? x.to_s.delete('@')
end.map do |x|
  [x.to_s.delete('@'), bar.instance_variable_get(x)]
end.to_h
# > {'alpha': 1, 'charlie': :masked_value}