Module: Delivered::Signature

Defined in:
lib/delivered/signature.rb

Instance Method Summary collapse

Instance Method Details

#sig(*sig_args, **sig_kwargs, &return_blk) ⇒ Object 



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# File 'lib/delivered/signature.rb', line 5

def sig(*sig_args, **sig_kwargs, &return_blk)
  # Block return
  returns = return_blk&.call

  # Hashrocket return
  if sig_kwargs.keys[0].is_a?(Array)
    unless returns.nil?
      raise Delivered::ArgumentError,
            'Cannot mix block and hash for return type. Use one or the other.', caller
    end

    returns = sig_kwargs.values[0]
    sig_args = sig_kwargs.keys[0]
    sig_kwargs = sig_args.pop if sig_args.last.is_a?(Hash)
  end

  # ap(sig_args:, sig_kwargs:)

  meta = class << self; self; end
  sig_check = lambda do |klass, class_method, name, *args, **kwargs, &block| # rubocop:disable Metrics/BlockLength
    # ap(args:, kwargs:, params: klass.method(:"__#{name}").parameters)

    cname = class_method ? "#{klass.name}.#{name}" : "#{klass.class.name}##{name}"

    sig_args.each.with_index do |arg, i|
      args[i] => ^arg
    rescue NoMatchingPatternError => e
      raise Delivered::ArgumentError,
            "`#{cname}` expected #{arg.inspect} as argument #{i}, but received " \
            "`#{args[i].inspect}`",
            caller, cause: e
    end

    unless sig_kwargs.empty?
      kwargs.each do |key, value|
        value => ^(sig_kwargs[key])
      rescue NoMatchingPatternError => e
        raise Delivered::ArgumentError,
              "`#{cname}` expected #{sig_kwargs[key].inspect} as keyword argument :#{key}, " \
              "but received `#{value.inspect}`",
              caller, cause: e
      end
    end

    result = if block
               klass.send(:"__#{name}", *args, **kwargs, &block)
             else
               klass.send(:"__#{name}", *args, **kwargs)
             end

    begin
      result => ^returns unless returns.nil?
    rescue NoMatchingPatternError => e
      raise Delivered::ArgumentError,
            "`#{cname}` expected to return #{returns.inspect}, " \
            "but returned `#{result.inspect}`",
            caller, cause: e
    end

    result
  end

  # Instance method redefinition
  meta.send :define_method, :method_added do |name|
    meta.send :remove_method, :method_added
    meta.send :remove_method, :singleton_method_added

    alias_method :"__#{name}", name
    define_method name do |*args, **kwargs, &block|
      sig_check.call(self, false, name, *args, **kwargs, &block)
    end
  end

  # Class method redefinition
  meta.send :define_method, :singleton_method_added do |name|
    next if name == :singleton_method_added

    meta.send :remove_method, :singleton_method_added
    meta.send :remove_method, :method_added

    meta.alias_method :"__#{name}", name
    define_singleton_method name do |*args, **kwargs, &block|
      sig_check.call(self, true, name, *args, **kwargs, &block)
    end
  end
end