Preserve idempotent compatibility

Author: ioquatix

lib/protocol/http/request.rb

@@ -132,21 +132,32 @@ def self.[](method, path = nil, _headers = nil, _body = nil, scheme: nil, author
 				self.new(scheme, authority, method, path, nil, headers, body, protocol, interim_response)
 			end
 
-			# Whether the request method is idempotent according to HTTP semantics.
+			# Whether the request can be replayed without side-effects.
 			def idempotent?
-				case @method
-				when Methods::POST, Methods::PATCH, Methods::CONNECT
-					false
-				else
-					true
+				# QUERY requests are idempotent, even if they have a body:
+				if @method == Methods::QUERY
+					return true
+				end
+				
+				# POST requests are not idempotent, even if they have no body:
+				if @method == Methods::POST
+					return false
 				end
+				
+				# All other requests are idempotent if they have no body:
+				if @body.nil? || @body.empty?
+					return true
+				end
+				
+				# Otherwise, we don't know if the request is idempotent or not, so we assume it is not:
+				return false
 			end
 
 			# Prepare the request body to be sent again, if it is safe to retry.
 			# @returns [Boolean] Whether the request was prepared for retry.
 			def retry!
-				# Only idempotent requests can be retried safely.
-				if !self.idempotent?
+				# Only idempotent request methods can be retried safely.
+				if @method == Methods::POST || @method == Methods::PATCH || @method == Methods::CONNECT
 					return false
 				end
 

test/protocol/http/request.rb

@@ -147,16 +147,16 @@
 		with "PUT request with a body" do
 			let(:request) {subject["PUT", "/resource", body: "content"]}
 
-			it "should be idempotent" do
-				expect(request).to be(:idempotent?)
+			it "should not be idempotent" do
+				expect(request).not.to be(:idempotent?)
 			end
 		end
 
 		with "PATCH request without a body" do
 			let(:request) {subject["PATCH", "/resource"]}
 
-			it "should not be idempotent" do
-				expect(request).not.to be(:idempotent?)
+			it "should be idempotent" do
+				expect(request).to be(:idempotent?)
 			end
 		end
 
@@ -168,7 +168,7 @@
 			with "idempotent request with a rewindable body" do
 				let(:request) {subject["PUT", "/resource", body: "content"]}
 
-				it "rewinds the body" do
+				it "allows retry and rewinds the body" do
 					expect(request.body.read).to be == "content"
 
 					expect(request.retry!).to be == true
@@ -192,6 +192,14 @@
 					expect(request.retry!).to be == false
 				end
 			end
+			
+			with "PATCH request" do
+				let(:request) {subject["PATCH", "/resource"]}
+				
+				it "does not allow retry" do
+					expect(request.retry!).to be == false
+				end
+			end
 		end
 
 		it "should have a string representation" do