Introduce ActionDispatch::Reloader

Based on the implementation on the 2-3-stable branch, patches by Hongli
Lai <hongli@phusion.nl>, and helpful suggestions from José Valim.

Hongli Lai's patches included locking around the request cycle; this is
now handled by Rack::Lock (https://github.com/rack/rack/issues/issue/87/).

[#2873]

Signed-off-by: José Valim <jose.valim@gmail.com>

1 files changed, 139 insertions, 0 deletions

diff --git a/actionpack/test/dispatch/reloader_test.rb b/actionpack/test/dispatch/reloader_test.rb
new file mode 100644
index 0000000000..58ef346b5c
--- /dev/null
+++ b/actionpack/test/dispatch/reloader_test.rb
@@ -0,0 +1,139 @@
+require 'abstract_unit'
+
+class ReloaderTest < Test::Unit::TestCase
+  Reloader = ActionDispatch::Reloader
+
+  def test_prepare_callbacks
+    a = b = c = nil
+    Reloader.to_prepare { |*args| a = b = c = 1 }
+    Reloader.to_prepare { |*args| b = c = 2 }
+    Reloader.to_prepare { |*args| c = 3 }
+
+    # Ensure to_prepare callbacks are not run when defined
+    assert_nil a || b || c
+
+    # Run callbacks
+    call_and_return_body
+
+    assert_equal 1, a
+    assert_equal 2, b
+    assert_equal 3, c
+  end
+
+  def test_to_prepare_with_identifier_replaces
+    a = b = 0
+    Reloader.to_prepare(:unique_id) { |*args| a = b = 1 }
+    Reloader.to_prepare(:unique_id) { |*args| a = 2 }
+
+    call_and_return_body
+    assert_equal 2, a
+    assert_equal 0, b
+  end
+
+  class MyBody < Array
+    def initialize(&block)
+      @on_close = block
+    end
+
+    def foo
+      "foo"
+    end
+
+    def bar
+      "bar"
+    end
+
+    def close
+      @on_close.call if @on_close
+    end
+  end
+
+  def test_returned_body_object_always_responds_to_close
+    body = call_and_return_body
+    assert body.respond_to?(:close)
+  end
+
+  def test_returned_body_object_behaves_like_underlying_object
+    body = call_and_return_body do
+      b = MyBody.new
+      b << "hello"
+      b << "world"
+      [200, { "Content-Type" => "text/html" }, b]
+    end
+    assert_equal 2, body.size
+    assert_equal "hello", body[0]
+    assert_equal "world", body[1]
+    assert_equal "foo", body.foo
+    assert_equal "bar", body.bar
+  end
+
+  def test_it_calls_close_on_underlying_object_when_close_is_called_on_body
+    close_called = false
+    body = call_and_return_body do
+      b = MyBody.new do
+        close_called = true
+      end
+      [200, { "Content-Type" => "text/html" }, b]
+    end
+    body.close
+    assert close_called
+  end
+
+  def test_returned_body_object_responds_to_all_methods_supported_by_underlying_object
+    body = call_and_return_body do
+      [200, { "Content-Type" => "text/html" }, MyBody.new]
+    end
+    assert body.respond_to?(:size)
+    assert body.respond_to?(:each)
+    assert body.respond_to?(:foo)
+    assert body.respond_to?(:bar)
+  end
+
+  def test_cleanup_callbacks_are_called_when_body_is_closed
+    cleaned = false
+    Reloader.to_cleanup { cleaned = true }
+
+    body = call_and_return_body
+    assert !cleaned
+
+    body.close
+    assert cleaned
+  end
+
+  def test_prepare_callbacks_arent_called_when_body_is_closed
+    prepared = false
+    Reloader.to_prepare { prepared = true }
+
+    body = call_and_return_body
+    prepared = false
+
+    body.close
+    assert !prepared
+  end
+
+  def test_manual_reloading
+    prepared = cleaned = false
+    Reloader.to_prepare { prepared = true }
+    Reloader.to_cleanup { cleaned  = true }
+
+    Reloader.prepare!
+    assert prepared
+    assert !cleaned
+
+    prepared = cleaned = false
+    Reloader.cleanup!
+    assert !prepared
+    assert cleaned
+
+    prepared = cleaned = false
+    Reloader.reload!
+    assert prepared
+    assert cleaned
+  end
+
+  private
+    def call_and_return_body(&block)
+      @reloader ||= Reloader.new(block || proc {[200, {}, 'response']})
+      @reloader.call({'rack.input' => StringIO.new('')})[2]
+    end
+end