Refactor refvartransformer with kyaml

api/testutils/filtertest/runfilter.go

@@ -11,7 +11,7 @@ import (
 	"sigs.k8s.io/kustomize/kyaml/kio"
 )
 
-func RunFilter(t *testing.T, input string, f kio.Filter) string {
+func run(input string, f kio.Filter) (string, error) {
 	var out bytes.Buffer
 	rw := kio.ByteReadWriter{
 		Reader: bytes.NewBufferString(input),
@@ -23,8 +23,26 @@ func RunFilter(t *testing.T, input string, f kio.Filter) string {
 		Filters: []kio.Filter{f},
 		Outputs: []kio.Writer{&rw},
 	}.Execute()
+	if err != nil {
+		return "", err
+	}
+	return out.String(), nil
+}
+
+// RunFilter runs filter and panic if there is error
+func RunFilter(t *testing.T, input string, f kio.Filter) string {
+	output, err := run(input, f)
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
-	return out.String()
+	return output
+}
+
+// RunFilterE runs filter and return error if there is
+func RunFilterE(t *testing.T, input string, f kio.Filter) (string, error) {
+	output, err := run(input, f)
+	if err != nil {
+		return "", err
+	}
+	return output, nil
 }