Module: T::Props::Private::DeserializerGenerator
- Extended by:
- Sig
- Defined in:
- lib/types/props/private/deserializer_generator.rb
Overview
Generates a specialized ‘deserialize` 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 deserializing 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
Class Method Details
.generate(props, defaults) ⇒ Object
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# File 'lib/types/props/private/deserializer_generator.rb', line 31 def self.generate(props, defaults) 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]) transformation = SerdeTransform.generate( T::Utils::Nilable.(rules.fetch(:type_object)), SerdeTransform::Mode::DESERIALIZE, 'val' ) transformed_val = if transformation # Rescuing exactly NoMethodError is intended as a temporary hack # to preserve the semantics from before codegen. More generally # we are inconsistent about typechecking on deser and need to decide # our strategy here. <<~RUBY begin #{transformation} rescue NoMethodError => e raise_deserialization_error( #{prop.inspect}, val, e, ) val end RUBY else 'val' end nil_handler = generate_nil_handler( prop: prop, serialized_form: hash_key, default: defaults[prop], nilable_type: T::Props::Utils.optional_prop?(rules), raise_on_nil_write: !!rules[:raise_on_nil_write], ) <<~RUBY val = hash[#{hash_key.inspect}] #{ivar_name} = if val.nil? found -= 1 unless hash.key?(#{hash_key.inspect}) #{nil_handler} else #{transformed_val} end RUBY end <<~RUBY def __t_props_generated_deserialize(hash) found = #{stored_props.size} #{parts.join("\n\n")} found end RUBY end |