fix webhook method null and add test case

handlers/webhook.go

@@ -27,9 +27,10 @@ func SendWebhooksExternal(r *http.Request, configWebhook interface{}) error {
 		return fmt.Errorf("invalid url %s", err)
 	}
 
-	method := webhook["method"].(string)
-	if method == "" {
-		method = "POST"
+	method := "POST"
+	methodVal, ok := webhook["method"]
+	if ok && methodVal != nil {
+		method = methodVal.(string)
 	}
 
 	req, _ := http.NewRequest(method, webhook["url"].(string), r.Body)

handlers/webhook_test.go

@@ -43,6 +43,21 @@ func TestSendWebhooksExternal_NoHeaders(t *testing.T) {
 	assert.NoError(t, err)
 }
 
+func TestSendWebhooksExternal_NoMethod(t *testing.T) {
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusOK)
+		w.Write([]byte(`{"data": "success"}`))
+	}))
+
+	req := httptest.NewRequest(http.MethodPost, "https://foo.bar/webhook", nil)
+	webhookConfig := map[string]interface{}{
+		"url": ts.URL,
+	}
+
+	err := SendWebhooksExternal(req, webhookConfig)
+	assert.NoError(t, err)
+}
+
 func TestSendWebhooks(t *testing.T) {
 	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		w.WriteHeader(http.StatusOK)