Module: T::Props::Private::SerializerGenerator

Extended by:
Sig
Defined in:
lib/types/props/private/serializer_generator.rb

Overview

Generates a specialized ‘serialize` implementation for a subclass of T::Props::Serializable.

The basic idea is that we analyze the props and for each prop, generate the simplest possible logic as a block of Ruby source, so that we don’t pay the cost of supporting types like T:::Hash[CustomType, SubstructType] when serializing a simple Integer. Then we join those together, with a little shared logic to be able to detect when we get input keys that don’t match any prop.

Class Method Summary collapse

Methods included from Sig

sig

Class Method Details

.generate(props) ⇒ Object 



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# File 'lib/types/props/private/serializer_generator.rb', line 26

def self.generate(props)
  stored_props = props.reject {|_, rules| rules[:dont_store]}
  parts = stored_props.map do |prop, rules|
    # All of these strings should already be validated (directly or
    # indirectly) in `validate_prop_name`, so we don't bother with a nice
    # error message, but we double check here to prevent a refactoring
    # from introducing a security vulnerability.
    raise unless T::Props::Decorator::SAFE_NAME.match?(prop.to_s)

    hash_key = rules.fetch(:serialized_form)
    raise unless T::Props::Decorator::SAFE_NAME.match?(hash_key)

    ivar_name = rules.fetch(:accessor_key).to_s
    raise unless ivar_name.start_with?('@') && T::Props::Decorator::SAFE_NAME.match?(ivar_name[1..-1])

    transformed_val = SerdeTransform.generate(
      T::Utils::Nilable.get_underlying_type_object(rules.fetch(:type_object)),
      SerdeTransform::Mode::SERIALIZE,
      ivar_name
    ) || ivar_name

    nil_asserter =
      if rules[:fully_optional]
        ''
      else
        "required_prop_missing_from_serialize(#{prop.inspect}) if strict"
      end

    # Don't serialize values that are nil to save space (both the
    # nil value itself and the field name in the serialized BSON
    # document)
    <<~RUBY
      if #{ivar_name}.nil?
        #{nil_asserter}
      else
        h[#{hash_key.inspect}] = #{transformed_val}
      end
    RUBY
  end

  <<~RUBY
    def __t_props_generated_serialize(strict)
      h = {}
      #{parts.join("\n\n")}
      h
    end
  RUBY
end