test: cover TransactionalFixtures, Widget

test/test_testing_transactional.rb

@@ -0,0 +1,142 @@
+require 'minitest/autorun'
+require 'prism'
+require 'tmpdir'
+
+# Fixtures shared by the two test classes below live in their own module so
+# the dedicated Store/Model pair is built exactly once, at file-load time,
+# and both classes (the "victim" whose #run gets exercised, and the class
+# that verifies it) see the same Widget table.
+module TransactionalFixtures
+  DIR = Dir.mktmpdir('prism-transactional-tests')
+  STORE = Prism::Orm::Store.new(File.join(DIR, 'test.pstore'))
+  STORE.create_table(:widgets, %w[id name])
+
+  class Widget < Prism::Orm::Model
+    self.store = STORE
+    table_name :widgets
+
+    class << self
+      attr_accessor :rollback_count
+    end
+    self.rollback_count = 0
+
+    after_rollback { self.class.rollback_count += 1 }
+  end
+
+  # A second, INDEPENDENT Store (own file, own PStore, own TransactionRegistry)
+  # standing in for something like a separate jobs queue database that a
+  # single test method might write to alongside the main one.
+  OTHER_STORE = Prism::Orm::Store.new(File.join(DIR, 'other.pstore'))
+  OTHER_STORE.create_table(:gadgets, %w[id name])
+
+  class Gadget < Prism::Orm::Model
+    self.store = OTHER_STORE
+    table_name :gadgets
+  end
+end
+
+# Auto-discovered and run by Minitest like any other test class in this
+# suite (contributing its own pass/fail to the run) - AND instantiated and
+# `.run` manually, more than once, by TestTestingTransactional below to
+# prove writes never survive between runs. Both uses must be safe together,
+# since transactional rollback makes every run self-contained: whichever
+# caller runs it, the widgets table is back to empty by the time #run returns.
+class TransactionalVictimTest < Minitest::Test
+  include Prism::Testing::IntegrationTest
+  use_transactional_tests(store: TransactionalFixtures::STORE)
+
+  def test_creates_exactly_one_widget
+    TransactionalFixtures::Widget.create!(name: 'gizmo')
+    assert_equal 1, TransactionalFixtures::Widget.count
+  end
+end
+
+# Writes to BOTH independent stores in a single test method - proves the
+# `stores:` (plural) option rolls back every one of them, not just the
+# first or the last.
+class MultiStoreVictimTest < Minitest::Test
+  include Prism::Testing::IntegrationTest
+  use_transactional_tests(stores: [TransactionalFixtures::STORE, TransactionalFixtures::OTHER_STORE])
+
+  def test_creates_a_widget_and_a_gadget
+    TransactionalFixtures::Widget.create!(name: 'gizmo')
+    TransactionalFixtures::Gadget.create!(name: 'sprocket')
+    assert_equal 1, TransactionalFixtures::Widget.count
+    assert_equal 1, TransactionalFixtures::Gadget.count
+  end
+end
+
+# Regression guard for classes that never call `use_transactional_tests` -
+# their #run must behave exactly as plain Minitest::Test, unaffected by the
+# override living in the shared module.
+class PlainIntegrationSampleTest < Minitest::Test
+  include Prism::Testing::IntegrationTest
+
+  def test_noop
+    assert true
+  end
+end
+
+class TestTestingTransactional < Minitest::Test
+  Widget = TransactionalFixtures::Widget
+
+  def test_writes_are_rolled_back_once_the_test_finishes
+    assert_equal 0, Widget.count
+    result = TransactionalVictimTest.new(:test_creates_exactly_one_widget).run
+    assert result.passed?, result.failures.map(&:message).join("\n")
+    assert_equal 0, Widget.count, 'the widget created inside the test should not survive it'
+  end
+
+  def test_running_the_same_test_twice_never_sees_a_leftover_row
+    result1 = TransactionalVictimTest.new(:test_creates_exactly_one_widget).run
+    result2 = TransactionalVictimTest.new(:test_creates_exactly_one_widget).run
+    assert result1.passed?, result1.failures.map(&:message).join("\n")
+    assert result2.passed?, result2.failures.map(&:message).join("\n")
+    assert_equal 0, Widget.count
+  end
+
+  def test_after_rollback_callbacks_fire_when_the_transaction_unwinds
+    before = Widget.rollback_count
+    result = TransactionalVictimTest.new(:test_creates_exactly_one_widget).run
+    assert result.passed?, result.failures.map(&:message).join("\n")
+    assert_equal before + 1, Widget.rollback_count
+  end
+
+  def test_classes_that_never_opt_in_are_unaffected
+    result = PlainIntegrationSampleTest.new(:test_noop).run
+    assert result.passed?, result.failures.map(&:message).join("\n")
+  end
+
+  def test_transactional_tests_store_is_inherited_by_subclasses
+    subclass = Class.new(TransactionalVictimTest)
+    assert_equal TransactionalFixtures::STORE, subclass.transactional_tests_store
+  end
+
+  def test_default_store_option_resolves_to_prism_orm_store_lazily
+    klass = Class.new(Minitest::Test) do
+      include Prism::Testing::IntegrationTest
+      use_transactional_tests
+    end
+    assert_equal :default, klass.transactional_tests_store
+    assert_equal [:default], klass.transactional_tests_stores
+  end
+
+  def test_multiple_stores_all_roll_back_after_the_test_finishes
+    assert_equal 0, TransactionalFixtures::Widget.count
+    assert_equal 0, TransactionalFixtures::Gadget.count
+
+    result = MultiStoreVictimTest.new(:test_creates_a_widget_and_a_gadget).run
+    assert result.passed?, result.failures.map(&:message).join("\n")
+
+    assert_equal 0, TransactionalFixtures::Widget.count,
+                 'the widget in the FIRST configured store must not survive the test'
+    assert_equal 0, TransactionalFixtures::Gadget.count,
+                 'the gadget in the SECOND, independent store must not survive the test either'
+  end
+
+  def test_stores_option_is_exposed_as_an_array_and_store_returns_its_first_element
+    assert_equal [TransactionalFixtures::STORE, TransactionalFixtures::OTHER_STORE],
+                 MultiStoreVictimTest.transactional_tests_stores
+    assert_equal TransactionalFixtures::STORE, MultiStoreVictimTest.transactional_tests_store
+  end
+end

test/test_view.rb

@@ -52,4 +52,16 @@ class ViewTest < Minitest::Test
     error = assert_raises(Prism::View::TemplateNotFound) { @view.render('posts/missing') }
     assert_includes error.message, 'posts/missing'
   end
+
+  def test_render_emits_a_render_template_event_per_template_file
+    events = []
+    subscriber = Prism::Instrumentation.subscribe('render_template.prism') { |event| events << event }
+    begin
+      @view.render('posts/index', locals: { greeting: 'hi' }, layout: :application)
+    ensure
+      Prism::Instrumentation.unsubscribe(subscriber)
+    end
+
+    assert_equal %w[posts/index layouts/application], events.map { |e| e.payload[:identifier] }
+  end
 end