Update testing.go

check for errors before expected response

gqltesting/testing.go

@@ -43,6 +43,9 @@ func RunTest(t *testing.T, test *Test) {
 		test.Context = context.Background()
 	}
 	result := test.Schema.Exec(test.Context, test.Query, test.OperationName, test.Variables)
+
+	checkErrors(t, test.ExpectedErrors, result.Errors)
+
 	// Verify JSON to avoid red herring errors.
 	got, err := formatJSON(result.Data)
 	if err != nil {
@@ -53,8 +56,6 @@ func RunTest(t *testing.T, test *Test) {
 		t.Fatalf("want: invalid JSON: %s", err)
 	}
 
-	checkErrors(t, test.ExpectedErrors, result.Errors)
-
 	if !bytes.Equal(got, want) {
 		t.Logf("got:  %s", got)
 		t.Logf("want: %s", want)