Fixup #449 : buffer body for default edge case (#450)

* Fixup #449 : buffer body for default edge case

* Fixup, ignore situation for websocket configurations

* Add additional testcases

eval/context.go

@@ -244,10 +244,13 @@ func newBerespValues(ctx context.Context, readBody bool, beresp *http.Response)
 		}
 	} else if bOk && (bufferOption&BufferResponse) != BufferResponse {
 		hasBlock, _ := bereq.Context().Value(request.ResponseBlock).(bool)
+		ws, _ := bereq.Context().Value(request.WebsocketsAllowed).(bool)
 		if name != "default" || (name == "default" && hasBlock) {
 			// beresp body is not referenced and can be closed
 			// prevent resource leak, free connection
 			_ = beresp.Body.Close()
+		} else if !ws {
+			parseSetRespBody(beresp)
 		}
 	}
 
@@ -430,24 +433,33 @@ func parseReqBody(req *http.Request) (cty.Value, cty.Value) {
 func parseRespBody(beresp *http.Response) (cty.Value, cty.Value) {
 	jsonBody := cty.EmptyObjectVal
 
-	if beresp == nil || beresp.Body == nil {
+	b := parseSetRespBody(beresp)
+	if b == nil {
 		return cty.NilVal, jsonBody
 	}
 
+	if isJSONMediaType(beresp.Header.Get("Content-Type")) {
+		jsonBody = parseJSONBytes(b)
+	}
+	return cty.StringVal(string(b)), jsonBody
+}
+
+func parseSetRespBody(beresp *http.Response) []byte {
+	if beresp == nil || beresp.Body == nil {
+		return nil
+	}
+
 	b, err := io.ReadAll(beresp.Body)
 	if err != nil {
-		return cty.NilVal, jsonBody
+		return nil
 	}
 
 	// prevent resource leak
 	_ = beresp.Body.Close()
 
 	beresp.Body = io.NopCloser(bytes.NewBuffer(b)) // reset
 
-	if isJSONMediaType(beresp.Header.Get("Content-Type")) {
-		jsonBody = parseJSONBytes(b)
-	}
-	return cty.StringVal(string(b)), jsonBody
+	return b
 }
 
 func parseJSONBytes(b []byte) cty.Value {

server/http_backend_test.go

@@ -3,6 +3,7 @@ package server_test
 import (
 	"context"
 	"encoding/json"
+	"io"
 	"net/http"
 	"net/http/httptest"
 	"testing"
@@ -38,6 +39,8 @@ func TestBackend_MaxConnections_BodyClose(t *testing.T) {
 		"/",
 		"/named",
 		"/default",
+		"/default2",
+		"/ws",
 	}
 
 	for _, p := range paths {
@@ -51,5 +54,10 @@ func TestBackend_MaxConnections_BodyClose(t *testing.T) {
 		if res.StatusCode != http.StatusOK {
 			t.Errorf("want: 200, got %d", res.StatusCode)
 		}
+
+		_, err = io.Copy(io.Discard, res.Body)
+		helper.Must(err)
+
+		helper.Must(res.Body.Close())
 	}
 }

server/testdata/integration/backends/04_couper.hcl

@@ -37,6 +37,25 @@ server {
       backend = "be"
     }
   }
+
+  endpoint "/default2" {
+    request {
+      url = "{{ .origin }}/"
+      backend = "be"
+    }
+    request "a" {
+      url = "{{ .origin }}/"
+      backend = "be"
+    }
+  }
+
+  endpoint "/ws" {
+    proxy {
+      url = "{{ .origin }}/"
+      websockets = true
+      backend = "be"
+    }
+  }
 }
 
 definitions {