MF-982 - Add error when connecting empty channels or things (#985)

* Add error when connecting empty channels or things

Signed-off-by: nwneisen <nwneisen@gmail.com>

* Add more detailed test descriptions

Signed-off-by: nwneisen <nwneisen@gmail.com>

* Add to test descriptions

Signed-off-by: nwneisen <nwneisen@gmail.com>

* fix channel ids

Signed-off-by: nwneisen <nwneisen@gmail.com>

things/api/things/http/endpoint_test.go

@@ -1957,7 +1957,7 @@ func TestCreateConnections(t *testing.T) {
 			status:      http.StatusNotFound,
 		},
 		{
-			desc:        "invalid content type",
+			desc:        "connect with invalid content type",
 			channelIDs:  bchs,
 			thingIDs:    ths,
 			auth:        token,
@@ -1965,12 +1965,36 @@ func TestCreateConnections(t *testing.T) {
 			status:      http.StatusUnsupportedMediaType,
 		},
 		{
-			desc:        "invalid JSON",
+			desc:        "connect with invalid JSON",
 			auth:        token,
 			contentType: contentType,
 			status:      http.StatusBadRequest,
 			body:        "{",
 		},
+		{
+			desc:        "connect valid thing ids with empty channel ids",
+			channelIDs:  []string{},
+			thingIDs:    ths,
+			auth:        token,
+			contentType: contentType,
+			status:      http.StatusBadRequest,
+		},
+		{
+			desc:        "connect valid channel ids with empty thing ids",
+			channelIDs:  achs,
+			thingIDs:    []string{},
+			auth:        token,
+			contentType: contentType,
+			status:      http.StatusBadRequest,
+		},
+		{
+			desc:        "connect empty channel ids and empty thing ids",
+			channelIDs:  []string{},
+			thingIDs:    []string{},
+			auth:        token,
+			contentType: contentType,
+			status:      http.StatusBadRequest,
+		},
 	}
 
 	for _, tc := range cases {

things/api/things/http/requests.go

@@ -252,6 +252,10 @@ func (req createConnectionsReq) validate() error {
 		return things.ErrUnauthorizedAccess
 	}
 
+	if len(req.ChannelIDs) == 0 || len(req.ThingIDs) == 0 {
+		return things.ErrMalformedEntity
+	}
+
 	for _, chID := range req.ChannelIDs {
 		if chID == "" {
 			return things.ErrMalformedEntity