Fix: Adhese handle 200 response with empty array body (prebid#3323)

adapters/adhese/adhese.go

@@ -141,6 +141,9 @@ func (a *AdheseAdapter) MakeBids(internalRequest *openrtb2.BidRequest, externalR
 		return nil, []error{err, WrapServerError(fmt.Sprintf("Response %v could not be parsed as generic Adhese bid.", string(response.Body)))}
 	}
 
+	if len(adheseBidResponseArray) == 0 {
+		return nil, nil
+	}
 	var adheseBid = adheseBidResponseArray[0]
 
 	if adheseBid.Origin == "JERLICIA" {

adapters/adhese/adhesetest/supplemental/res-no_bids_200.json

@@ -0,0 +1,54 @@
+{
+  "mockBidRequest": {
+    "id": "test-req",
+    "user": {
+      "ext": {
+        "consent" : "dummy"
+      }
+    },
+    "imp": [
+      {
+        "id": "test-req",
+        "banner": {
+          "format": [
+            {
+              "w": 300,
+              "h": 250
+            }
+          ]
+        },
+        "ext": {
+          "bidder": {
+            "account": "demo",
+            "location": "_adhese_prebid_demo_",
+            "format": "leaderboard",
+            "targets": 
+            {
+              "ci": ["gent", "brussels"],
+              "ag": ["55"],
+              "tl": ["all"]
+            }
+          }
+        }
+      }
+    ],
+    "site": {
+      "id": "test",
+      "publisher": {
+        "id": "123"
+      }
+    }
+  },
+  "httpCalls": [
+    {
+      "expectedRequest": {
+        "uri": "https://ads-demo.adhese.com/json/sl_adhese_prebid_demo_-leaderboard/ag55/cigent;brussels/tlall/xtdummy"
+      },
+      "mockResponse": {
+        "status": 200,
+        "body": []
+      }
+    }
+  ],
+  "expectedBidResponses": []
+}