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# frozen_string_literal: true
module Necromancer
# A class responsible for wrapping conversion target
#
# @api private
class ConversionTarget
# Used as a stand in for lack of value
# @api private
UndefinedValue = Module.new
# @api private
def initialize(conversions, object)
@object = object
@conversions = conversions
end
# @api private
def self.for(context, value, block)
if UndefinedValue.equal?(value)
unless block
raise ArgumentError,
"You need to pass either argument or a block to `convert`."
end
new(context, block.call)
elsif block
raise ArgumentError,
"You cannot pass both an argument and a block to `convert`."
else
new(context, value)
end
end
# Allows to specify conversion source type
#
# @example
# converter.convert("1").from(:string).to(:numeric) # => 1
#
# @return [ConversionType]
#
# @api public
def from(source)
@source = source
self
end
# Runs a given conversion
#
# @example
# converter.convert("1").to(:numeric) # => 1
#
# @example
# converter.convert("1") >> Integer # => 1
#
# @return [Object]
# the converted target type
#
# @api public
def to(target, options = {})
conversion = conversions[source || detect(object, false), detect(target)]
conversion.call(object, **options)
end
alias >> to
# Inspect this conversion
#
# @api public
def inspect
%(#<#{self.class}@#{object_id} @object=#{object}, @source=#{detect(object)}>)
end
protected
# Detect object type and coerce into known key type
#
# @param [Object] object
#
# @api private
def detect(object, symbol_as_object = true)
case object
when TrueClass, FalseClass then :boolean
when Integer then :integer
when Class then object.name.downcase
else
if object.is_a?(Symbol) && symbol_as_object
object
else
object.class.name.downcase
end
end
end
attr_reader :object
attr_reader :conversions
attr_reader :source
end # ConversionTarget
end # Necromancer
|
