Extend inttest RetryWatchErrors unit test

It used to use syscall.EBADFD, which is not defined on Darwin. Use the
generic test error instead, which is platform-independent and does the
job just as well. Also, add a test case for the retry delay suggestion
detection.

Signed-off-by: Tom Wieczorek <[email protected]>

inttest/common/util_test.go

@@ -17,10 +17,14 @@ limitations under the License.
 package common
 
 import (
+	"fmt"
+	"io"
 	"syscall"
 	"testing"
 	"time"
 
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+
 	"github.com/stretchr/testify/assert"
 )
 
@@ -37,9 +41,11 @@ func TestRetryWatchErrors_syscalls(t *testing.T) {
 	}{
 		{name: "ECONNRESET", err: syscall.ECONNRESET, expectedDelay: defaultRetryDelay, expectedError: nil},
 		{name: "ECONNREFUSED", err: syscall.ECONNREFUSED, expectedDelay: defaultRetryDelay, expectedError: nil},
+		{name: "EOF", err: io.EOF, expectedDelay: defaultRetryDelay, expectedError: nil},
+		{name: "retryAfter(42)", err: retryAfterError(42), expectedDelay: 42 * time.Second, expectedError: nil},
 
 		// The fallthrough case, don't expect retries with this.
-		{name: "EBADFD", err: syscall.EBADFD, expectedDelay: 0, expectedError: syscall.EBADFD},
+		{name: "AnError", err: assert.AnError, expectedDelay: 0, expectedError: assert.AnError},
 	}
 
 	for _, test := range tests {
@@ -52,3 +58,16 @@ func TestRetryWatchErrors_syscalls(t *testing.T) {
 		})
 	}
 }
+
+type retryAfterError int32
+
+func (e retryAfterError) Error() string {
+	return fmt.Sprintf("retryAfterError(%d)", int32(e))
+}
+
+func (e retryAfterError) Status() metav1.Status {
+	return metav1.Status{
+		Reason:  metav1.StatusReasonServerTimeout,
+		Details: &metav1.StatusDetails{RetryAfterSeconds: int32(e)},
+	}
+}