package metrics import ( "bytes" "encoding/json" "testing" ) func TestRegistryMarshallJSON(t *testing.T) { b := &bytes.Buffer{} enc := json.NewEncoder(b) r := NewRegistry() r.Register("counter", NewCounter()) enc.Encode(r) if s := b.String(); "{\"counter\":{\"count\":0}}\n" != s { t.Fatalf(s) } }