class Tapioca::Compilers::Dsl::Protobuf

`Tapioca::Compilers::Dsl::Protobuf` decorates RBI files for subclasses of [`Google::Protobuf::MessageExts`](github.com/protocolbuffers/protobuf/tree/master/ruby).

For example, with the following “cart.rb” file:

~~~rb Google::Protobuf::DescriptorPool.generated_pool.build do

add_file("cart.proto", :syntax => :proto3) do
  add_message "MyCart" do
    optional :shop_id, :int32, 1
    optional :customer_id, :int64, 2
    optional :number_value, :double, 3
    optional :string_value, :string, 4
  end
end

end ~~~

this generator will produce the RBI file `cart.rbi` with the following content:

~~~rbi # cart.rbi # typed: strong class Cart

sig { returns(Integer) }
def customer_id; end

sig { params(month: Integer).returns(Integer) }
def customer_id=(value); end

sig { returns(Integer) }
def shop_id; end

sig { params(value: Integer).returns(Integer) }
def shop_id=(value); end

sig { returns(String) }
def string_value; end

sig { params(value: String).returns(String) }
def string_value=(value); end

sig { returns(Float) }
def number_value; end

sig { params(value: Float).returns(Float) }
def number_value=(value); end

end ~~~

Public Instance Methods

decorate(root, constant) click to toggle source
# File lib/tapioca/compilers/dsl/protobuf.rb, line 74
def decorate(root, constant)
  root.create_path(constant) do |klass|
    if constant == Google::Protobuf::RepeatedField
      create_type_members(klass, "Elem")
    elsif constant == Google::Protobuf::Map
      create_type_members(klass, "Key", "Value")
    else
      descriptor = T.let(T.unsafe(constant).descriptor, Google::Protobuf::Descriptor)
      fields = descriptor.map { |desc| create_descriptor_method(klass, desc) }
      fields.sort_by!(&:name)

      parameters = fields.map do |field|
        create_kw_opt_param(field.name, type: field.init_type, default: field.default)
      end

      klass.create_method("initialize", parameters: parameters, return_type: "void")
    end
  end
end
gather_constants() click to toggle source
# File lib/tapioca/compilers/dsl/protobuf.rb, line 95
def gather_constants
  marker = Google::Protobuf::MessageExts::ClassMethods
  results = T.cast(ObjectSpace.each_object(marker).to_a, T::Array[Module])
  results.any? ? results + [Google::Protobuf::RepeatedField, Google::Protobuf::Map] : []
end

Private Instance Methods

create_descriptor_method(klass, desc) click to toggle source
# File lib/tapioca/compilers/dsl/protobuf.rb, line 191
def create_descriptor_method(klass, desc)
  field = field_of(desc)

  klass.create_method(
    field.name,
    return_type: field.type
  )

  klass.create_method(
    "#{field.name}=",
    parameters: [create_param("value", type: field.type)],
    return_type: field.type
  )

  field
end
create_type_members(klass, *names) click to toggle source
# File lib/tapioca/compilers/dsl/protobuf.rb, line 104
def create_type_members(klass, *names)
  klass.create_extend("T::Generic")

  names.each do |name|
    klass.create_type_member(name)
  end
end
field_of(descriptor) click to toggle source
# File lib/tapioca/compilers/dsl/protobuf.rb, line 137
def field_of(descriptor)
  if descriptor.label == :repeated
    # Here we're going to check if the submsg_name is named according to
    # how Google names map entries.
    # https://github.com/protocolbuffers/protobuf/blob/f82e26/ruby/ext/google/protobuf_c/defs.c#L1963-L1966
    if descriptor.submsg_name.to_s.end_with?("_MapEntry_#{descriptor.name}")
      key = descriptor.subtype.lookup("key")
      value = descriptor.subtype.lookup("value")

      key_type = type_of(key)
      value_type = type_of(value)
      type = "Google::Protobuf::Map[#{key_type}, #{value_type}]"

      default_args = [key.type.inspect, value.type.inspect]
      default_args << value_type if [:enum, :message].include?(value.type)

      Field.new(
        name: descriptor.name,
        type: type,
        init_type: "T.any(#{type}, T::Hash[#{key_type}, #{value_type}])",
        default: "Google::Protobuf::Map.new(#{default_args.join(", ")})"
      )
    else
      elem_type = type_of(descriptor)
      type = "Google::Protobuf::RepeatedField[#{elem_type}]"

      default_args = [descriptor.type.inspect]
      default_args << elem_type if [:enum, :message].include?(descriptor.type)

      Field.new(
        name: descriptor.name,
        type: type,
        init_type: "T.any(#{type}, T::Array[#{elem_type}])",
        default: "Google::Protobuf::RepeatedField.new(#{default_args.join(", ")})"
      )
    end
  else
    type = type_of(descriptor)

    Field.new(
      name: descriptor.name,
      type: type,
      init_type: type,
      default: "nil"
    )
  end
end
type_of(descriptor) click to toggle source
# File lib/tapioca/compilers/dsl/protobuf.rb, line 117
def type_of(descriptor)
  case descriptor.type
  when :enum
    descriptor.subtype.enummodule.name
  when :message
    descriptor.subtype.msgclass.name
  when :int32, :int64, :uint32, :uint64
    "Integer"
  when :double, :float
    "Float"
  when :bool
    "T::Boolean"
  when :string, :bytes
    "String"
  else
    "T.untyped"
  end
end