From 6a9709f7b8639e7f19a7c745ad5bd92811c3482d Mon Sep 17 00:00:00 2001
From: smavros <stemavros@gmail.com>
Date: Sun, 11 Aug 2019 16:55:20 +0200
Subject: [PATCH] Improves LengthOfResponse() utility function:

    Problems arise from the fact that the are two kind of successful
    responses: The array of objects response like
    {"key":[{obj1},{obj2},...]} and the single object response like
    {"key":{obj}}. The function will try to check if the response can be
    unmarshaled in an array of generic type variables so to match the
    first case. If not it will try to unmarshal to a single generic type
    variable and 1 will be returned as the length of the response. If
    this will also fail -1 will be returned.
---
 common/utilities.go | 39 ++++++++++++++++++++++++++-------------
 1 file changed, 26 insertions(+), 13 deletions(-)

diff --git a/common/utilities.go b/common/utilities.go
index 6af18ad..c37588a 100644
--- a/common/utilities.go
+++ b/common/utilities.go
@@ -40,7 +40,6 @@ func LengthOfResponse(router *gin.Engine, token string, url string,
 	method string, body []byte) int {
 
 	w := httptest.NewRecorder()
-	responseLength := 0
 
 	if body != nil {
 		req, _ := http.NewRequest(method, url, bytes.NewBuffer(body))
@@ -53,23 +52,37 @@ func LengthOfResponse(router *gin.Engine, token string, url string,
 		router.ServeHTTP(w, req)
 	}
 
-	// Get the response
-	var body_data map[string][]interface{}
+	// Convert the response in array of bytes
+	responseBytes := []byte(w.Body.String())
 
-	err := json.Unmarshal([]byte(w.Body.String()), &body_data)
-	if err != nil {
-		return responseLength
+	// First we are trying to unmarshal the response into an array of
+	// general type variables ([]interface{}). If this fails we will try
+	// to unmarshal into a single general type variable (interface{}).
+	// If that also fails we will return -1.
+
+	// Response might be array of objects
+	var arrayResponse map[string][]interface{}
+	err := json.Unmarshal(responseBytes, &arrayResponse)
+	if err == nil {
+
+		// Get an arbitrary key from tha map. The only key (entry) of
+		// course is the model's name. With that trick we do not have to
+		// pass the higher level key as argument.
+		for arbitrary_tag := range arrayResponse {
+			return len(arrayResponse[arbitrary_tag])
+		}
 	}
 
-	// Get an arbitrary key from tha map. The only key (entry) of course
-	// is the model's name. With that trick we do not have to pass the
-	// higher level key as argument.
-	for arbitrary_tag := range body_data {
-		responseLength = len(body_data[arbitrary_tag])
-		break
+	// Response might be a single object
+	var singleResponse map[string]interface{}
+	err = json.Unmarshal(responseBytes, &singleResponse)
+	if err == nil {
+		return 1
 	}
 
-	return responseLength
+	// Failed to identify response. It means we got a different HTTP
+	// code than 200.
+	return -1
 }
 
 func NewTestEndpoint(router *gin.Engine, token string, url string,