Add test for failed enumerable stream.

Author: samuel-williams-shopify

lib/protocol/rack/body/enumerable.rb

@@ -107,8 +107,10 @@ def stream?
 				# @parameter stream [Object] The stream to write the body to.
 				def call(stream)
 					@body.call(stream)
+				rescue => error
+					raise
 				ensure
-					self.close($!)
+					self.close(error)
 				end
 
 				# Read the next chunk from the response body.

test/protocol/rack/body/enumerable.rb

@@ -41,4 +41,22 @@
 			end.to raise_exception(RuntimeError, message: be =~ /Bad Enumerable/)
 		end
 	end
+
+	with "#call" do
+		let(:bad_callable) do
+			proc do |stream|
+				raise "Bad Callable"
+			end
+		end
+
+		let(:body) {subject.new(bad_callable, 1)}
+
+		it "streams the body" do
+			expect(body).to receive(:close)
+
+			expect do
+				body.call(nil)
+			end.to raise_exception(RuntimeError, message: be =~ /Bad Callable/)
+		end
+	end
 end