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require 'abstract_unit'
require 'fixtures/topic'
require 'fixtures/developer'
class TransactionTest < Test::Unit::TestCase
self.use_transactional_fixtures = false
fixtures :topics, :developers
def setup
# sqlite does not seem to return these in the right order, so we sort them
# explicitly for sqlite's sake. sqlite3 does fine.
@first, @second = Topic.find(1, 2).sort_by { |t| t.id }
end
def test_successful
Topic.transaction do
@first.approved = true
@second.approved = false
@first.save
@second.save
end
assert Topic.find(1).approved?, "First should have been approved"
assert !Topic.find(2).approved?, "Second should have been unapproved"
end
def transaction_with_return
Topic.transaction do
@first.approved = true
@second.approved = false
@first.save
@second.save
return
end
end
def test_successful_with_return
class << Topic.connection
alias :real_commit_db_transaction :commit_db_transaction
def commit_db_transaction
$committed = true
real_commit_db_transaction
end
end
$committed = false
transaction_with_return
assert $committed
assert Topic.find(1).approved?, "First should have been approved"
assert !Topic.find(2).approved?, "Second should have been unapproved"
ensure
class << Topic.connection
alias :commit_db_transaction :real_commit_db_transaction rescue nil
end
end
def test_successful_with_instance_method
@first.transaction do
@first.approved = true
@second.approved = false
@first.save
@second.save
end
assert Topic.find(1).approved?, "First should have been approved"
assert !Topic.find(2).approved?, "Second should have been unapproved"
end
def test_failing_on_exception
begin
Topic.transaction do
@first.approved = true
@second.approved = false
@first.save
@second.save
raise "Bad things!"
end
rescue
# caught it
end
assert @first.approved?, "First should still be changed in the objects"
assert !@second.approved?, "Second should still be changed in the objects"
assert !Topic.find(1).approved?, "First shouldn't have been approved"
assert Topic.find(2).approved?, "Second should still be approved"
end
def test_failing_with_object_rollback
assert !@first.approved?, "First should be unapproved initially"
begin
Topic.transaction(@first, @second) do
@first.approved = true
@second.approved = false
@first.save
@second.save
raise "Bad things!"
end
rescue
# caught it
end
assert !@first.approved?, "First shouldn't have been approved"
assert @second.approved?, "Second should still be approved"
end
def test_callback_rollback_in_save
add_exception_raising_after_save_callback_to_topic
begin
@first.approved = true
@first.save
flunk
rescue => e
assert_equal "Make the transaction rollback", e.message
assert !Topic.find(1).approved?
ensure
remove_exception_raising_after_save_callback_to_topic
end
end
def test_nested_explicit_transactions
Topic.transaction do
Topic.transaction do
@first.approved = true
@second.approved = false
@first.save
@second.save
end
end
assert Topic.find(1).approved?, "First should have been approved"
assert !Topic.find(2).approved?, "Second should have been unapproved"
end
# This will cause transactions to overlap and fail unless they are
# performed on separate database connections.
def test_transaction_per_thread
assert_nothing_raised do
threads = (1..20).map do
Thread.new do
Topic.transaction do
topic = Topic.find(:first)
topic.approved = !topic.approved?
topic.save!
topic.approved = !topic.approved?
topic.save!
end
end
end
threads.each { |t| t.join }
end
end
# Test for dirty reads among simultaneous transactions.
def test_transaction_isolation__read_committed
# Should be invariant.
original_salary = Developer.find(1).salary
temporary_salary = 200000
assert_nothing_raised do
threads = (1..20).map do
Thread.new do
Developer.transaction do
# Expect original salary.
dev = Developer.find(1)
assert_equal original_salary, dev.salary
dev.salary = temporary_salary
dev.save!
# Expect temporary salary.
dev = Developer.find(1)
assert_equal temporary_salary, dev.salary
dev.salary = original_salary
dev.save!
# Expect original salary.
dev = Developer.find(1)
assert_equal original_salary, dev.salary
end
end
end
# Keep our eyes peeled.
threads << Thread.new do
10.times do
sleep 0.05
Developer.transaction do
# Always expect original salary.
assert_equal original_salary, Developer.find(1).salary
end
end
end
threads.each { |t| t.join }
end
assert_equal original_salary, Developer.find(1).salary
end
private
def add_exception_raising_after_save_callback_to_topic
Topic.class_eval { def after_save() raise "Make the transaction rollback" end }
end
def remove_exception_raising_after_save_callback_to_topic
Topic.class_eval { remove_method :after_save }
end
end
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