From 05af5c9ef891c7b8c6009eab335991ff35164916 Mon Sep 17 00:00:00 2001
From: Alex Pana <8968914+acpana@users.noreply.github.com>
Date: Fri, 13 Oct 2023 23:57:14 +0000
Subject: [PATCH] flesh out errorList

Signed-off-by: Alex Pana <8968914+acpana@users.noreply.github.com>
---
 pkg/watch/errorlist.go | 44 +++++++++++++++++++++++++++++++++---------
 pkg/watch/manager.go   |  8 ++++----
 2 files changed, 39 insertions(+), 13 deletions(-)

diff --git a/pkg/watch/errorlist.go b/pkg/watch/errorlist.go
index 4065b3c2a0e..a691efc63f4 100644
--- a/pkg/watch/errorlist.go
+++ b/pkg/watch/errorlist.go
@@ -16,16 +16,17 @@ limitations under the License.
 package watch
 
 import (
+	"errors"
 	"fmt"
 	"strings"
 
 	"k8s.io/apimachinery/pkg/runtime/schema"
 )
 
-// errorList is an error that aggregates multiple gvkErrs.
+// errorList is an error that aggregates multiple errors.
 type errorList struct {
-	errs        []gvkErr
-	isUniversal bool
+	errs                 []error
+	containsUniversalErr bool
 }
 
 type WatchesError interface {
@@ -50,11 +51,11 @@ func (w gvkErr) Error() string {
 	return fmt.Sprintf("error for gvk: %s: %s", w.gvk, w.err.Error())
 }
 
-func (e errorList) String() string {
+func (e *errorList) String() string {
 	return e.Error()
 }
 
-func (e errorList) Error() string {
+func (e *errorList) Error() string {
 	var builder strings.Builder
 	for i, err := range e.errs {
 		if i > 0 {
@@ -65,15 +66,40 @@ func (e errorList) Error() string {
 	return builder.String()
 }
 
-func (e errorList) FailingGVKs() []schema.GroupVersionKind {
+// returns a new errorList type.
+func newErrList() *errorList {
+	return &errorList{
+		errs: []error{},
+	}
+}
+
+func (e *errorList) FailingGVKs() []schema.GroupVersionKind {
 	gvks := make([]schema.GroupVersionKind, len(e.errs))
 	for _, err := range e.errs {
-		gvks = append(gvks, err.gvk)
+		var gvkErr gvkErr
+		if errors.As(err, &gvkErr) {
+			gvks = append(gvks, gvkErr.gvk)
+		}
 	}
 
 	return gvks
 }
 
-func (e errorList) IsUniversal() bool {
-	return e.isUniversal
+func (e *errorList) IsUniversal() bool {
+	return e.containsUniversalErr
+}
+
+// adds a non gvk specific error to the list.
+func (e *errorList) Add(err error) {
+	e.errs = append(e.errs, err)
+	e.containsUniversalErr = true
+}
+
+// adds a gvk specific error to the list.
+func (e *errorList) AddGVKErr(gvk schema.GroupVersionKind, err error) {
+	e.errs = append(e.errs, gvkErr{gvk: gvk, err: err})
+}
+
+func (e *errorList) Size() int {
+	return len(e.errs)
 }
diff --git a/pkg/watch/manager.go b/pkg/watch/manager.go
index a54137a10e0..a6aefb95c61 100644
--- a/pkg/watch/manager.go
+++ b/pkg/watch/manager.go
@@ -254,7 +254,7 @@ func (wm *Manager) replaceWatches(ctx context.Context, r *Registrar) error {
 	wm.watchedMux.Lock()
 	defer wm.watchedMux.Unlock()
 
-	errlist := errorList{errs: []gvkErr{}}
+	errlist := newErrList()
 
 	desired := wm.managedKinds.Get()
 	for gvk := range wm.watchedKinds {
@@ -263,7 +263,7 @@ func (wm *Manager) replaceWatches(ctx context.Context, r *Registrar) error {
 			continue
 		}
 		if err := wm.doRemoveWatch(ctx, r, gvk); err != nil {
-			errlist.errs = append(errlist.errs, gvkErr{gvk: gvk, err: fmt.Errorf("removing watch for %+v %w", gvk, err)})
+			errlist.AddGVKErr(gvk, fmt.Errorf("removing watch for %+v %w", gvk, err))
 		}
 	}
 
@@ -273,7 +273,7 @@ func (wm *Manager) replaceWatches(ctx context.Context, r *Registrar) error {
 			continue
 		}
 		if err := wm.doAddWatch(ctx, r, gvk); err != nil {
-			errlist.errs = append(errlist.errs, gvkErr{gvk: gvk, err: fmt.Errorf("adding watch for %+v %w", gvk, err)})
+			errlist.AddGVKErr(gvk, fmt.Errorf("adding watch for %+v %w", gvk, err))
 		}
 	}
 
@@ -281,7 +281,7 @@ func (wm *Manager) replaceWatches(ctx context.Context, r *Registrar) error {
 		log.Error(err, "while trying to report gvk count metric")
 	}
 
-	if len(errlist.errs) > 0 {
+	if errlist.Size() > 0 {
 		return errlist
 	}
 	return nil