fix: check for empty body in response using http.NoBody

Author: henripqt

responses/validate_body_test.go

@@ -532,7 +532,9 @@ paths:
 	response := &http.Response{
 		Header:     http.Header{},
 		StatusCode: http.StatusOK,
-		Body:       nil, // invalid response body
+		// The http Client and Transport guarantee that Body is always non-nil
+		// and will be set to [http.NoBody] if no body is present.
+		Body: http.NoBody,
 	}
 	response.Header.Set(helpers.ContentTypeHeader, helpers.JSONContentType)
 

responses/validate_response.go

@@ -45,7 +45,7 @@ func ValidateResponseSchema(
 
 	var validationErrors []*errors.ValidationError
 
-	if response == nil || response.Body == nil {
+	if response == nil || response.Body == http.NoBody {
 		// cannot decode the response body, so it's not valid
 		violation := &errors.SchemaValidationFailure{
 			Reason:          "response is empty",