Publish AS::Executor and AS::Reloader APIs

These should allow external code to run blocks of user code to do
"work", at a similar unit size to a web request, without needing to get
intimate with ActionDipatch.

2 files changed, 161 insertions, 0 deletions

diff --git a/activesupport/test/executor_test.rb b/activesupport/test/executor_test.rb
new file mode 100644
index 0000000000..6db6db4fa8
--- /dev/null
+++ b/activesupport/test/executor_test.rb
@@ -0,0 +1,76 @@
+require 'abstract_unit'
+
+class ExecutorTest < ActiveSupport::TestCase
+  def test_wrap_invokes_callbacks
+    called = []
+    executor.to_run { called << :run }
+    executor.to_complete { called << :complete }
+
+    executor.wrap do
+      called << :body
+    end
+
+    assert_equal [:run, :body, :complete], called
+  end
+
+  def test_callbacks_share_state
+    result = false
+    executor.to_run { @foo = true }
+    executor.to_complete { result = @foo }
+
+    executor.wrap { }
+
+    assert result
+  end
+
+  def test_separated_calls_invoke_callbacks
+    called = []
+    executor.to_run { called << :run }
+    executor.to_complete { called << :complete }
+
+    state = executor.run!
+    called << :body
+    state.complete!
+
+    assert_equal [:run, :body, :complete], called
+  end
+
+  def test_avoids_double_wrapping
+    called = []
+    executor.to_run { called << :run }
+    executor.to_complete { called << :complete }
+
+    executor.wrap do
+      called << :early
+      executor.wrap do
+        called << :body
+      end
+      called << :late
+    end
+
+    assert_equal [:run, :early, :body, :late, :complete], called
+  end
+
+  def test_separate_classes_can_wrap
+    other_executor = Class.new(ActiveSupport::Executor)
+
+    called = []
+    executor.to_run { called << :run }
+    executor.to_complete { called << :complete }
+    other_executor.to_run { called << :other_run }
+    other_executor.to_complete { called << :other_complete }
+
+    executor.wrap do
+      other_executor.wrap do
+        called << :body
+      end
+    end
+
+    assert_equal [:run, :other_run, :body, :other_complete, :complete], called
+  end
+
+  private
+    def executor
+      @executor ||= Class.new(ActiveSupport::Executor)
+    end
+end
diff --git a/activesupport/test/reloader_test.rb b/activesupport/test/reloader_test.rb
new file mode 100644
index 0000000000..958cb49993
--- /dev/null
+++ b/activesupport/test/reloader_test.rb
@@ -0,0 +1,85 @@
+require 'abstract_unit'
+
+class ReloaderTest < ActiveSupport::TestCase
+  def test_prepare_callback
+    prepared = false
+    reloader.to_prepare { prepared = true }
+
+    assert !prepared
+    reloader.prepare!
+    assert prepared
+
+    prepared = false
+    reloader.wrap do
+      assert prepared
+      prepared = false
+    end
+    assert !prepared
+  end
+
+  def test_only_run_when_check_passes
+    r = new_reloader { true }
+    invoked = false
+    r.to_run { invoked = true }
+    r.wrap { }
+    assert invoked
+
+    r = new_reloader { false }
+    invoked = false
+    r.to_run { invoked = true }
+    r.wrap { }
+    assert !invoked
+  end
+
+  def test_full_reload_sequence
+    called = []
+    reloader.to_prepare { called << :prepare }
+    reloader.to_run { called << :reloader_run }
+    reloader.to_complete { called << :reloader_complete }
+    reloader.executor.to_run { called << :executor_run }
+    reloader.executor.to_complete { called << :executor_complete }
+
+    reloader.wrap { }
+    assert_equal [:executor_run, :reloader_run, :prepare, :reloader_complete, :executor_complete], called
+
+    called = []
+    reloader.reload!
+    assert_equal [:executor_run, :reloader_run, :prepare, :reloader_complete, :executor_complete, :prepare], called
+
+    reloader.check = lambda { false }
+
+    called = []
+    reloader.wrap { }
+    assert_equal [:executor_run, :executor_complete], called
+
+    called = []
+    reloader.reload!
+    assert_equal [:executor_run, :reloader_run, :prepare, :reloader_complete, :executor_complete, :prepare], called
+  end
+
+  def test_class_unload_block
+    called = []
+    reloader.before_class_unload { called << :before_unload }
+    reloader.after_class_unload { called << :after_unload }
+    reloader.to_run do
+      class_unload! do
+        called << :unload
+      end
+    end
+    reloader.wrap { called << :body }
+
+    assert_equal [:before_unload, :unload, :after_unload, :body], called
+  end
+
+  private
+    def new_reloader(&check)
+      Class.new(ActiveSupport::Reloader).tap do |r|
+        r.check = check
+        r.executor = Class.new(ActiveSupport::Executor)
+      end
+    end
+
+    def reloader
+      @reloader ||= new_reloader { true }
+    end
+end