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rails--rails/activerecord/test/cases/attribute_test.rb
Sean Griffin 07723c23a7 Further encapsulate dirty checking on Attribute
We can skip the allocation of a full `AttributeSet` by changing the
semantics of how we structure things. Instead of comparing two separate
`AttributeSet` objects, and `Attribute` is now a singly linked list of
every change that has happened to it. Since the attribute objects are
immutable, to apply the changes we simply need to copy the head of the
list.

It's worth noting that this causes one subtle change in the behavior of
AR. When a record is saved successfully, the `before_type_cast` version
of everything will be what was sent to the database. I honestly think
these semantics make more sense, as we could have just as easily had the
DB do `RETURNING *` and updated the record with those if we had things
like timestamps implemented at the DB layer.

This brings our performance closer to 4.2, but we're still not quite
there.
2015-10-02 08:03:11 -04:00

246 lines
7.9 KiB
Ruby

require 'cases/helper'
module ActiveRecord
class AttributeTest < ActiveRecord::TestCase
setup do
@type = Minitest::Mock.new
end
teardown do
assert @type.verify
end
test "from_database + read type casts from database" do
@type.expect(:deserialize, 'type cast from database', ['a value'])
attribute = Attribute.from_database(nil, 'a value', @type)
type_cast_value = attribute.value
assert_equal 'type cast from database', type_cast_value
end
test "from_user + read type casts from user" do
@type.expect(:cast, 'type cast from user', ['a value'])
attribute = Attribute.from_user(nil, 'a value', @type)
type_cast_value = attribute.value
assert_equal 'type cast from user', type_cast_value
end
test "reading memoizes the value" do
@type.expect(:deserialize, 'from the database', ['whatever'])
attribute = Attribute.from_database(nil, 'whatever', @type)
type_cast_value = attribute.value
second_read = attribute.value
assert_equal 'from the database', type_cast_value
assert_same type_cast_value, second_read
end
test "reading memoizes falsy values" do
@type.expect(:deserialize, false, ['whatever'])
attribute = Attribute.from_database(nil, 'whatever', @type)
attribute.value
attribute.value
end
test "read_before_typecast returns the given value" do
attribute = Attribute.from_database(nil, 'raw value', @type)
raw_value = attribute.value_before_type_cast
assert_equal 'raw value', raw_value
end
test "from_database + read_for_database type casts to and from database" do
@type.expect(:deserialize, 'read from database', ['whatever'])
@type.expect(:serialize, 'ready for database', ['read from database'])
attribute = Attribute.from_database(nil, 'whatever', @type)
serialize = attribute.value_for_database
assert_equal 'ready for database', serialize
end
test "from_user + read_for_database type casts from the user to the database" do
@type.expect(:cast, 'read from user', ['whatever'])
@type.expect(:serialize, 'ready for database', ['read from user'])
attribute = Attribute.from_user(nil, 'whatever', @type)
serialize = attribute.value_for_database
assert_equal 'ready for database', serialize
end
test "duping dups the value" do
@type.expect(:deserialize, 'type cast', ['a value'])
attribute = Attribute.from_database(nil, 'a value', @type)
value_from_orig = attribute.value
value_from_clone = attribute.dup.value
value_from_orig << ' foo'
assert_equal 'type cast foo', value_from_orig
assert_equal 'type cast', value_from_clone
end
test "duping does not dup the value if it is not dupable" do
@type.expect(:deserialize, false, ['a value'])
attribute = Attribute.from_database(nil, 'a value', @type)
assert_same attribute.value, attribute.dup.value
end
test "duping does not eagerly type cast if we have not yet type cast" do
attribute = Attribute.from_database(nil, 'a value', @type)
attribute.dup
end
class MyType
def cast(value)
value + " from user"
end
def deserialize(value)
value + " from database"
end
def assert_valid_value(*)
end
end
test "with_value_from_user returns a new attribute with the value from the user" do
old = Attribute.from_database(nil, "old", MyType.new)
new = old.with_value_from_user("new")
assert_equal "old from database", old.value
assert_equal "new from user", new.value
end
test "with_value_from_database returns a new attribute with the value from the database" do
old = Attribute.from_user(nil, "old", MyType.new)
new = old.with_value_from_database("new")
assert_equal "old from user", old.value
assert_equal "new from database", new.value
end
test "uninitialized attributes yield their name if a block is given to value" do
block = proc { |name| name.to_s + "!" }
foo = Attribute.uninitialized(:foo, nil)
bar = Attribute.uninitialized(:bar, nil)
assert_equal "foo!", foo.value(&block)
assert_equal "bar!", bar.value(&block)
end
test "uninitialized attributes have no value" do
assert_nil Attribute.uninitialized(:foo, nil).value
end
test "attributes equal other attributes with the same constructor arguments" do
first = Attribute.from_database(:foo, 1, Type::Integer.new)
second = Attribute.from_database(:foo, 1, Type::Integer.new)
assert_equal first, second
end
test "attributes do not equal attributes with different names" do
first = Attribute.from_database(:foo, 1, Type::Integer.new)
second = Attribute.from_database(:bar, 1, Type::Integer.new)
assert_not_equal first, second
end
test "attributes do not equal attributes with different types" do
first = Attribute.from_database(:foo, 1, Type::Integer.new)
second = Attribute.from_database(:foo, 1, Type::Float.new)
assert_not_equal first, second
end
test "attributes do not equal attributes with different values" do
first = Attribute.from_database(:foo, 1, Type::Integer.new)
second = Attribute.from_database(:foo, 2, Type::Integer.new)
assert_not_equal first, second
end
test "attributes do not equal attributes of other classes" do
first = Attribute.from_database(:foo, 1, Type::Integer.new)
second = Attribute.from_user(:foo, 1, Type::Integer.new)
assert_not_equal first, second
end
test "an attribute has not been read by default" do
attribute = Attribute.from_database(:foo, 1, Type::Value.new)
assert_not attribute.has_been_read?
end
test "an attribute has been read when its value is calculated" do
attribute = Attribute.from_database(:foo, 1, Type::Value.new)
attribute.value
assert attribute.has_been_read?
end
test "an attribute is not changed if it hasn't been assigned or mutated" do
attribute = Attribute.from_database(:foo, 1, Type::Value.new)
refute attribute.changed?
end
test "an attribute is changed if it's been assigned a new value" do
attribute = Attribute.from_database(:foo, 1, Type::Value.new)
changed = attribute.with_value_from_user(2)
assert changed.changed?
end
test "an attribute is not changed if it's assigned the same value" do
attribute = Attribute.from_database(:foo, 1, Type::Value.new)
unchanged = attribute.with_value_from_user(1)
refute unchanged.changed?
end
test "an attribute can not be mutated if it has not been read,
and skips expensive calculations" do
type_which_raises_from_all_methods = Object.new
attribute = Attribute.from_database(:foo, "bar", type_which_raises_from_all_methods)
assert_not attribute.changed_in_place?
end
test "an attribute is changed if it has been mutated" do
attribute = Attribute.from_database(:foo, "bar", Type::String.new)
attribute.value << "!"
assert attribute.changed_in_place?
assert attribute.changed?
end
test "an attribute can forget its changes" do
attribute = Attribute.from_database(:foo, "bar", Type::String.new)
changed = attribute.with_value_from_user("foo")
forgotten = changed.forgetting_assignment
assert changed.changed? # sanity check
refute forgotten.changed?
end
test "with_value_from_user validates the value" do
type = Type::Value.new
type.define_singleton_method(:assert_valid_value) do |value|
if value == 1
raise ArgumentError
end
end
attribute = Attribute.from_database(:foo, 1, type)
assert_equal 1, attribute.value
assert_equal 2, attribute.with_value_from_user(2).value
assert_raises ArgumentError do
attribute.with_value_from_user(1)
end
end
end
end