fix: use empty results instead of nil

Signed-off-by: Jesse Simpson <jesse.simpson36@gmail.com>

pkg/kube/client.go

@@ -689,19 +689,19 @@ func (c *Client) Update(originals, targets ResourceList, options ...ClientUpdate
 		errs = append(errs, o(&updateOptions))
 	}
 	if err := errors.Join(errs...); err != nil {
-		return nil, fmt.Errorf("invalid client update option(s): %w", err)
+		return &Result{}, fmt.Errorf("invalid client update option(s): %w", err)
 	}
 
 	if updateOptions.threeWayMergeForUnstructured && updateOptions.serverSideApply {
-		return nil, fmt.Errorf("invalid operation: cannot use three-way merge for unstructured and server-side apply together")
+		return &Result{}, fmt.Errorf("invalid operation: cannot use three-way merge for unstructured and server-side apply together")
 	}
 
 	if updateOptions.forceConflicts && updateOptions.forceReplace {
-		return nil, fmt.Errorf("invalid operation: cannot use force conflicts and force replace together")
+		return &Result{}, fmt.Errorf("invalid operation: cannot use force conflicts and force replace together")
 	}
 
 	if updateOptions.serverSideApply && updateOptions.forceReplace {
-		return nil, fmt.Errorf("invalid operation: cannot use server-side apply and force replace together")
+		return &Result{}, fmt.Errorf("invalid operation: cannot use server-side apply and force replace together")
 	}
 
 	makeUpdateApplyFunc := func() UpdateApplyFunc {

pkg/kube/fake/failing_kube_client.go

@@ -122,7 +122,7 @@ func (f *FailingKubeWaiter) WatchUntilReady(resources kube.ResourceList, d time.
 // Update returns the configured error if set or prints
 func (f *FailingKubeClient) Update(r, modified kube.ResourceList, options ...kube.ClientUpdateOption) (*kube.Result, error) {
 	if f.UpdateError != nil {
-		return nil, f.UpdateError
+		return &kube.Result{}, f.UpdateError
 	}
 	return f.PrintingKubeClient.Update(r, modified, options...)
 }