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Merge pull request #39882 from kamipo/simplify_attribute_type_decoration

Simplify attribute type decoration
This commit is contained in:
Ryuta Kamizono 2020-07-21 08:47:04 +09:00 committed by GitHub
commit b949e69c5d
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10 changed files with 68 additions and 260 deletions

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@ -1,88 +0,0 @@
# frozen_string_literal: true
module ActiveRecord
module AttributeDecorators # :nodoc:
extend ActiveSupport::Concern
included do
class_attribute :attribute_type_decorations, instance_accessor: false, default: TypeDecorator.new # :internal:
end
module ClassMethods # :nodoc:
# This method is an internal API used to create class macros such as
# +serialize+, and features like time zone aware attributes.
#
# Used to wrap the type of an attribute in a new type.
# When the schema for a model is loaded, attributes with the same name as
# +column_name+ will have their type yielded to the given block. The
# return value of that block will be used instead.
#
# Subsequent calls where +column_name+ and +decorator_name+ are the same
# will override the previous decorator, not decorate twice. This can be
# used to create idempotent class macros like +serialize+
def decorate_attribute_type(column_name, decorator_name, &block)
matcher = ->(name, _) { name == column_name.to_s }
key = "_#{column_name}_#{decorator_name}"
decorate_matching_attribute_types(matcher, key, &block)
end
# This method is an internal API used to create higher level features like
# time zone aware attributes.
#
# When the schema for a model is loaded, +matcher+ will be called for each
# attribute with its name and type. If the matcher returns a truthy value,
# the type will then be yielded to the given block, and the return value
# of that block will replace the type.
#
# Subsequent calls to this method with the same value for +decorator_name+
# will replace the previous decorator, not decorate twice. This can be
# used to ensure that class macros are idempotent.
def decorate_matching_attribute_types(matcher, decorator_name, &block)
reload_schema_from_cache
decorator_name = decorator_name.to_s
# Create new hashes so we don't modify parent classes
self.attribute_type_decorations = attribute_type_decorations.merge(decorator_name => [matcher, block])
end
private
def load_schema!
super
attribute_types.each do |name, type|
decorated_type = attribute_type_decorations.apply(name, type)
define_attribute(name, decorated_type)
end
end
end
class TypeDecorator # :nodoc:
delegate :clear, to: :@decorations
def initialize(decorations = {})
@decorations = decorations
end
def merge(*args)
TypeDecorator.new(@decorations.merge(*args))
end
def apply(name, type)
decorations = decorators_for(name, type)
decorations.inject(type) do |new_type, block|
block.call(new_type)
end
end
private
def decorators_for(name, type)
matching(name, type).map(&:last)
end
def matching(name, type)
@decorations.values.select do |(matcher, _)|
matcher.call(name, type)
end
end
end
end
end

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@ -69,12 +69,19 @@ module ActiveRecord
Coders::YAMLColumn.new(attr_name, class_name_or_coder) Coders::YAMLColumn.new(attr_name, class_name_or_coder)
end end
decorate_attribute_type(attr_name, :serialize) do |type| attr_name = attr_name.to_s
if type_incompatible_with_serialize?(type, class_name_or_coder) type, options = attributes_to_define_after_schema_loads[attr_name]
raise ColumnNotSerializableError.new(attr_name, type)
attribute(attr_name) do |cast_type|
if type && !type.is_a?(Proc)
cast_type = _lookup_cast_type(attr_name, type, options)
end end
Type::Serialized.new(type, coder) if type_incompatible_with_serialize?(cast_type, class_name_or_coder)
raise ColumnNotSerializableError.new(attr_name, cast_type)
end
Type::Serialized.new(cast_type, coder)
end end
end end

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@ -6,6 +6,10 @@ module ActiveRecord
module AttributeMethods module AttributeMethods
module TimeZoneConversion module TimeZoneConversion
class TimeZoneConverter < DelegateClass(Type::Value) # :nodoc: class TimeZoneConverter < DelegateClass(Type::Value) # :nodoc:
def self.new(subtype)
self === subtype ? subtype : super
end
def deserialize(value) def deserialize(value)
convert_time_to_time_zone(super) convert_time_to_time_zone(super)
end end
@ -64,21 +68,14 @@ module ActiveRecord
end end
module ClassMethods # :nodoc: module ClassMethods # :nodoc:
private def define_attribute(name, cast_type, **)
def inherited(subclass) if create_time_zone_conversion_attribute?(name, cast_type)
super cast_type = TimeZoneConverter.new(cast_type)
# We need to apply this decorator here, rather than on module inclusion. The closure
# created by the matcher would otherwise evaluate for `ActiveRecord::Base`, not the
# sub class being decorated. As such, changes to `time_zone_aware_attributes`, or
# `skip_time_zone_conversion_for_attributes` would not be picked up.
subclass.class_eval do
matcher = ->(name, type) { create_time_zone_conversion_attribute?(name, type) }
decorate_matching_attribute_types(matcher, "_time_zone_conversion") do |type|
TimeZoneConverter.new(type)
end
end
end end
super
end
private
def create_time_zone_conversion_attribute?(name, cast_type) def create_time_zone_conversion_attribute?(name, cast_type)
enabled_for_column = time_zone_aware_attributes && enabled_for_column = time_zone_aware_attributes &&
!skip_time_zone_conversion_for_attributes.include?(name.to_sym) !skip_time_zone_conversion_for_attributes.include?(name.to_sym)

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@ -246,17 +246,7 @@ module ActiveRecord
def load_schema! # :nodoc: def load_schema! # :nodoc:
super super
attributes_to_define_after_schema_loads.each do |name, (type, options)| attributes_to_define_after_schema_loads.each do |name, (type, options)|
case type define_attribute(name, _lookup_cast_type(name, type, options), **options.slice(:default))
when Symbol
adapter_name = ActiveRecord::Type.adapter_name_from(self)
type = ActiveRecord::Type.lookup(type, **options.except(:default), adapter: adapter_name)
when Proc
type = type[type_for_attribute(name)]
else
type ||= type_for_attribute(name)
end
define_attribute(name, type, **options.slice(:default))
end end
end end
@ -279,6 +269,18 @@ module ActiveRecord
end end
_default_attributes[name] = default_attribute _default_attributes[name] = default_attribute
end end
def _lookup_cast_type(name, type, options)
case type
when Symbol
adapter_name = ActiveRecord::Type.adapter_name_from(self)
ActiveRecord::Type.lookup(type, **options.except(:default), adapter: adapter_name)
when Proc
type[type_for_attribute(name)]
else
type || type_for_attribute(name)
end
end
end end
end end
end end

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@ -5,7 +5,6 @@ require "active_support/dependencies"
require "active_support/descendants_tracker" require "active_support/descendants_tracker"
require "active_support/time" require "active_support/time"
require "active_support/core_ext/class/subclasses" require "active_support/core_ext/class/subclasses"
require "active_record/attribute_decorators"
require "active_record/log_subscriber" require "active_record/log_subscriber"
require "active_record/explain_subscriber" require "active_record/explain_subscriber"
require "active_record/relation/delegation" require "active_record/relation/delegation"
@ -293,7 +292,6 @@ module ActiveRecord #:nodoc:
include Validations include Validations
include CounterCache include CounterCache
include Attributes include Attributes
include AttributeDecorators
include Locking::Optimistic include Locking::Optimistic
include Locking::Pessimistic include Locking::Pessimistic
include AttributeMethods include AttributeMethods

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@ -165,20 +165,12 @@ module ActiveRecord
super super
end end
private def define_attribute(name, cast_type, **) # :nodoc:
# We need to apply this decorator here, rather than on module inclusion. The closure if lock_optimistically && name == locking_column
# created by the matcher would otherwise evaluate for `ActiveRecord::Base`, not the cast_type = LockingType.new(cast_type)
# sub class being decorated. As such, changes to `lock_optimistically`, or
# `locking_column` would not be picked up.
def inherited(subclass)
subclass.class_eval do
is_lock_column = ->(name, _) { lock_optimistically && name == locking_column }
decorate_matching_attribute_types(is_lock_column, "_optimistic_locking") do |type|
LockingType.new(type)
end
end
super
end end
super
end
end end
end end
@ -186,6 +178,10 @@ module ActiveRecord
# `nil` values to `lock_version`, and not result in `ActiveRecord::StaleObjectError` # `nil` values to `lock_version`, and not result in `ActiveRecord::StaleObjectError`
# during update record. # during update record.
class LockingType < DelegateClass(Type::Value) # :nodoc: class LockingType < DelegateClass(Type::Value) # :nodoc:
def self.new(subtype)
self === subtype ? subtype : super
end
def deserialize(value) def deserialize(value)
super.to_i super.to_i
end end

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@ -1,127 +0,0 @@
# frozen_string_literal: true
require "cases/helper"
module ActiveRecord
class AttributeDecoratorsTest < ActiveRecord::TestCase
class Model < ActiveRecord::Base
self.table_name = "attribute_decorators_model"
end
class StringDecorator < SimpleDelegator
def initialize(delegate, decoration = "decorated!")
@decoration = decoration
super(delegate)
end
def cast(value)
"#{super} #{@decoration}"
end
alias deserialize cast
end
setup do
@connection = ActiveRecord::Base.connection
@connection.create_table :attribute_decorators_model, force: true do |t|
t.string :a_string
end
end
teardown do
return unless @connection
@connection.drop_table "attribute_decorators_model", if_exists: true
Model.attribute_type_decorations.clear
Model.reset_column_information
end
test "attributes can be decorated" do
model = Model.new(a_string: "Hello")
assert_equal "Hello", model.a_string
Model.decorate_attribute_type(:a_string, :test) { |t| StringDecorator.new(t) }
model = Model.new(a_string: "Hello")
assert_equal "Hello decorated!", model.a_string
end
test "decoration does not eagerly load existing columns" do
Model.reset_column_information
assert_no_queries do
Model.decorate_attribute_type(:a_string, :test) { |t| StringDecorator.new(t) }
end
end
test "undecorated columns are not touched" do
Model.attribute :another_string, :string, default: "something or other"
Model.decorate_attribute_type(:a_string, :test) { |t| StringDecorator.new(t) }
assert_equal "something or other", Model.new.another_string
end
test "decorators can be chained" do
Model.decorate_attribute_type(:a_string, :test) { |t| StringDecorator.new(t) }
Model.decorate_attribute_type(:a_string, :other) { |t| StringDecorator.new(t) }
model = Model.new(a_string: "Hello!")
assert_equal "Hello! decorated! decorated!", model.a_string
end
test "decoration of the same type multiple times is idempotent" do
Model.decorate_attribute_type(:a_string, :test) { |t| StringDecorator.new(t) }
Model.decorate_attribute_type(:a_string, :test) { |t| StringDecorator.new(t) }
model = Model.new(a_string: "Hello")
assert_equal "Hello decorated!", model.a_string
end
test "decorations occur in order of declaration" do
Model.decorate_attribute_type(:a_string, :test) { |t| StringDecorator.new(t) }
Model.decorate_attribute_type(:a_string, :other) do |type|
StringDecorator.new(type, "decorated again!")
end
model = Model.new(a_string: "Hello!")
assert_equal "Hello! decorated! decorated again!", model.a_string
end
test "decorating attributes does not modify parent classes" do
Model.attribute :another_string, :string, default: "whatever"
Model.decorate_attribute_type(:a_string, :test) { |t| StringDecorator.new(t) }
child_class = Class.new(Model)
child_class.decorate_attribute_type(:another_string, :test) { |t| StringDecorator.new(t) }
child_class.decorate_attribute_type(:a_string, :other) { |t| StringDecorator.new(t) }
model = Model.new(a_string: "Hello!")
child = child_class.new(a_string: "Hello!")
assert_equal "Hello! decorated!", model.a_string
assert_equal "whatever", model.another_string
assert_equal "Hello! decorated! decorated!", child.a_string
assert_equal "whatever decorated!", child.another_string
end
class Multiplier < SimpleDelegator
def cast(value)
return if value.nil?
value * 2
end
alias deserialize cast
end
test "decorating with a proc" do
Model.attribute :an_int, :integer
type_is_integer = proc { |_, type| type.type == :integer }
Model.decorate_matching_attribute_types type_is_integer, :multiplier do |type|
Multiplier.new(type)
end
model = Model.new(a_string: "whatever", an_int: 1)
assert_equal "whatever", model.a_string
assert_equal 2, model.an_int
end
end
end

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@ -14,7 +14,6 @@ module ActiveRecord
@klass = Class.new(Class.new { def self.initialize_generated_modules; end }) do @klass = Class.new(Class.new { def self.initialize_generated_modules; end }) do
def self.superclass; Base; end def self.superclass; Base; end
def self.base_class?; true; end def self.base_class?; true; end
def self.decorate_matching_attribute_types(*); end
include ActiveRecord::AttributeMethods include ActiveRecord::AttributeMethods

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@ -70,13 +70,36 @@ module ActiveRecord
test "extra options are forwarded to the type caster constructor" do test "extra options are forwarded to the type caster constructor" do
klass = Class.new(OverloadedType) do klass = Class.new(OverloadedType) do
attribute :starts_at, :datetime, precision: 3, limit: 2, scale: 1 attribute :starts_at, :datetime, precision: 3, limit: 2, scale: 1, default: -> { Time.now.utc }
end end
starts_at_type = klass.type_for_attribute(:starts_at) starts_at_type = klass.type_for_attribute(:starts_at)
assert_equal 3, starts_at_type.precision assert_equal 3, starts_at_type.precision
assert_equal 2, starts_at_type.limit assert_equal 2, starts_at_type.limit
assert_equal 1, starts_at_type.scale assert_equal 1, starts_at_type.scale
assert_kind_of Type::DateTime, starts_at_type
assert_instance_of Time, klass.new.starts_at
end
test "time zone aware attribute" do
with_timezone_config aware_attributes: true, zone: "Pacific Time (US & Canada)" do
klass = Class.new(OverloadedType) do
attribute :starts_at, :datetime, precision: 3, default: -> { Time.now.utc }
attribute :ends_at, default: -> { Time.now.utc }
end
starts_at_type = klass.type_for_attribute(:starts_at)
ends_at_type = klass.type_for_attribute(:ends_at)
assert_instance_of AttributeMethods::TimeZoneConversion::TimeZoneConverter, starts_at_type
assert_instance_of AttributeMethods::TimeZoneConversion::TimeZoneConverter, ends_at_type
assert_kind_of Type::DateTime, starts_at_type.__getobj__
assert_kind_of Type::DateTime, ends_at_type.__getobj__
assert_instance_of ActiveSupport::TimeWithZone, klass.new.starts_at
assert_instance_of ActiveSupport::TimeWithZone, klass.new.ends_at
end
end end
test "nonexistent attribute" do test "nonexistent attribute" do

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@ -1127,6 +1127,7 @@ ActiveRecord::Schema.define do
t.string :overloaded_string_with_limit, limit: 255 t.string :overloaded_string_with_limit, limit: 255
t.string :string_with_default, default: "the original default" t.string :string_with_default, default: "the original default"
t.string :inferred_string, limit: 255 t.string :inferred_string, limit: 255
t.datetime :starts_at, :ends_at
end end
create_table :users, force: true do |t| create_table :users, force: true do |t|