Tests for retry_utils

One can argue about how necessary they are,
but at least I remembered how to do golang.

pkg/util/retryutil/retry_util_test.go

@@ -0,0 +1,68 @@
+package retryutil
+
+import (
+	"errors"
+	"testing"
+)
+
+type mockTicker struct {
+	test    *testing.T
+	counter int
+}
+
+func (t *mockTicker) Stop() {}
+
+func (t *mockTicker) Tick() {
+	t.counter += 1
+}
+
+func TestRetryWorkerSuccess(t *testing.T) {
+	tick := &mockTicker{t, 0}
+	result := RetryWorker(10, 20, func() (bool, error) {
+		return true, nil
+	}, tick)
+
+	if result != nil {
+		t.Errorf("Wrong result, expected: %#v, got: %#v", nil, result)
+	}
+
+	if tick.counter != 0 {
+		t.Errorf("Ticker was started once, but it shouldn't be")
+	}
+}
+
+func TestRetryWorkerOneFalse(t *testing.T) {
+	var counter = 0
+
+	tick := &mockTicker{t, 0}
+	result := RetryWorker(1, 3, func() (bool, error) {
+		counter += 1
+
+		if counter <= 1 {
+			return false, nil
+		} else {
+			return true, nil
+		}
+	}, tick)
+
+	if result != nil {
+		t.Errorf("Wrong result, expected: %#v, got: %#v", nil, result)
+	}
+
+	if tick.counter != 1 {
+		t.Errorf("Ticker was started %#v, but supposed to be just once", tick.counter)
+	}
+}
+
+func TestRetryWorkerError(t *testing.T) {
+	fail := errors.New("Error")
+
+	tick := &mockTicker{t, 0}
+	result := RetryWorker(1, 3, func() (bool, error) {
+		return false, fail
+	}, tick)
+
+	if result != fail {
+		t.Errorf("Wrong result, expected: %#v, got: %#v", fail, result)
+	}
+}