Fixed HTTP.rb adapter, to allow streaming real responses, when WebMoc…

…k is enabled.

lib/webmock/http_lib_adapters/http_rb/response.rb

@@ -6,9 +6,19 @@ def to_webmock
       webmock_response = ::WebMock::Response.new
 
       webmock_response.status  = [status.to_i, reason]
+
       webmock_response.body    = body.to_s
-      webmock_response.headers = headers.to_h
+      # This call is used to reset the body of the response to enable it to be streamed if necessary.
+      # The `body.to_s` call above reads the body, which allows WebMock to trigger any registered callbacks.
+      # However, once the body is read to_s, it cannot be streamed again and attempting to do so
+      # will raise a "HTTP::StateError: body has already been consumed" error.
+      # To avoid this error, we replace the original body with a new one.
+      # The new body has its @stream attribute set to new Streamer, instead of the original Connection.
+      # Unfortunately, it's not possible to reset the original body to its initial streaming state.
+      # Therefore, this replacement is the best workaround currently available.
+      reset_body_to_allow_it_to_be_streamed!(webmock_response)
 
+      webmock_response.headers = headers.to_h
       webmock_response
     end
 
@@ -21,16 +31,7 @@ def from_webmock(request, webmock_response, request_signature = nil)
         # HTTP.rb 3.0+ uses a keyword argument to pass the encoding, but 1.x
         # and 2.x use a positional argument, and 0.x don't support supplying
         # the encoding.
-        body = if HTTP::VERSION < "1.0.0"
-          Body.new(Streamer.new(webmock_response.body))
-        elsif HTTP::VERSION < "3.0.0"
-          Body.new(Streamer.new(webmock_response.body), webmock_response.body.encoding)
-        else
-          Body.new(
-            Streamer.new(webmock_response.body, encoding: webmock_response.body.encoding),
-            encoding: webmock_response.body.encoding
-          )
-        end
+        body = build_http_rb_response_body_from_webmock_response(webmock_response)
 
         return new(status, "1.1", headers, body, uri) if HTTP::VERSION < "1.0.0"
 
@@ -54,7 +55,18 @@ def from_webmock(request, webmock_response, request_signature = nil)
         })
       end
 
-      private
+      def build_http_rb_response_body_from_webmock_response(webmock_response)
+        if HTTP::VERSION < "1.0.0"
+          Body.new(Streamer.new(webmock_response.body))
+        elsif HTTP::VERSION < "3.0.0"
+          Body.new(Streamer.new(webmock_response.body), webmock_response.body.encoding)
+        else
+          Body.new(
+            Streamer.new(webmock_response.body, encoding: webmock_response.body.encoding),
+            encoding: webmock_response.body.encoding
+          )
+        end
+      end
 
       def normalize_uri(uri)
         return unless uri
@@ -65,5 +77,11 @@ def normalize_uri(uri)
         uri
       end
     end
+
+    private
+
+    def reset_body_to_allow_it_to_be_streamed!(webmock_response)
+      @body = self.class.build_http_rb_response_body_from_webmock_response(webmock_response)
+    end
   end
 end

spec/acceptance/http_rb/http_rb_spec.rb

@@ -98,4 +98,20 @@
     http_request(:post, "http://www.example.com/", body: "abc")
   end
 
+  describe "when making real requests", net_connect: true do
+    before do
+      WebMock.allow_net_connect!
+    end
+
+    it "should allow streaming the response body" do
+      response = HTTP.get("http://localhost:#{WebMockServer.instance.port}")
+
+      read_body = ""
+      response.body.each do |chunk|
+        read_body << chunk
+      end
+
+      expect(read_body).to eql("hello world")
+    end
+  end
 end