fix(promotions): only check revision match sync result if found (#1923)

Signed-off-by: Hidde Beydals <hidde@hhh.computer>

internal/controller/promotion/argocd.go

@@ -220,17 +220,12 @@ func (a *argoCDMechanism) mustPerformUpdate(
 
 	// The operation has completed. Check if the desired revision was applied.
 	desiredRevision := libargocd.GetDesiredRevision(app, newFreight)
-	if desiredRevision == "" {
-		// We cannot determine the desired revision. Performing an update in this
-		// case wouldn't change anything. Instead, we should error out.
-		return "", false, errors.New("unable to determine desired revision")
-	}
 	if status.SyncResult == nil {
 		// We do not have a sync result, so we cannot determine if the operation
 		// was successful. The best recourse is to retry the operation.
 		return "", true, errors.New("operation completed without a sync result")
 	}
-	if status.SyncResult.Revision != desiredRevision {
+	if desiredRevision != "" && status.SyncResult.Revision != desiredRevision {
 		// The operation did not result in the desired revision being applied.
 		// We should attempt to retry the operation.
 		return "", true, fmt.Errorf(

internal/controller/promotion/argocd_test.go

@@ -519,11 +519,12 @@ func TestArgoCDMustPerformUpdate(t *testing.T) {
 							Username: applicationOperationInitiator,
 						},
 					},
+					SyncResult: &argocd.SyncOperationResult{},
 				}
 			},
 			assertions: func(t *testing.T, phase argocd.OperationPhase, mustUpdate bool, err error) {
-				require.ErrorContains(t, err, "unable to determine desired revision")
-				require.Empty(t, phase)
+				require.NoError(t, err)
+				require.Equal(t, argocd.OperationSucceeded, phase)
 				require.False(t, mustUpdate)
 			},
 		},