address comments

pkg/commands/testdata/testcase-multibases-conflict/base/kustomization.yaml

@@ -1,4 +1,4 @@
 resources:
 - serviceaccount.yaml
 - rolebinding.yaml
-namePrefix: base-
+namePrefix: base-

pkg/commands/testdata/testcase-multibases-conflict/overlays/a/kustomization.yaml

@@ -4,4 +4,4 @@ bases:
 namePrefix: a-
 
 resources:
-- serviceaccount.yaml
+- serviceaccount.yaml

pkg/commands/testdata/testcase-multibases-nonconflict/base/kustomization.yaml

@@ -1,4 +1,4 @@
 resources:
 - serviceaccount.yaml
 - rolebinding.yaml
-namePrefix: base-
+namePrefix: base-

pkg/resmap/resmap.go

@@ -145,7 +145,7 @@ func (m ResMap) insert(newName string, obj *unstructured.Unstructured) error {
 func (m ResMap) FilterBy(inputId resource.ResId) ResMap {
 	result := ResMap{}
 	for id, res := range m {
-		if id.Namespace() == inputId.Namespace() && id.HasSamePrefix(inputId) {
+		if id.Namespace() == inputId.Namespace() && id.HasSameLeftmostPrefix(inputId) {
 			result[id] = res
 		}
 	}

pkg/resource/resid.go

@@ -97,7 +97,7 @@ func (n ResId) Namespace() string {
 
 // CopyWithNewPrefix make a new copy from current ResId and append a new prefix
 func (n ResId) CopyWithNewPrefix(p string) ResId {
-	return ResId{gvk: n.gvk, name: n.name, prefix: n.concatePrefix(p), namespace: n.namespace}
+	return ResId{gvk: n.gvk, name: n.name, prefix: n.concatPrefix(p), namespace: n.namespace}
 }
 
 // CopyWithNewNamespace make a new copy from current ResId and set a new namespace
@@ -105,14 +105,15 @@ func (n ResId) CopyWithNewNamespace(ns string) ResId {
 	return ResId{gvk: n.gvk, name: n.name, prefix: n.prefix, namespace: ns}
 }
 
-// HasSamePrefix check if two ResIds have the same leading prefix
-func (n ResId) HasSamePrefix(id ResId) bool {
+// HasSameLeftmostPrefix check if two ResIds have the same
+// left most prefix.
+func (n ResId) HasSameLeftmostPrefix(id ResId) bool {
 	prefixes1 := n.prefixList()
 	prefixes2 := id.prefixList()
-	return len(prefixes1) == 0 || len(prefixes2) == 0 || prefixes1[0] == prefixes2[0]
+	return prefixes1[0] == prefixes2[0]
 }
 
-func (n ResId) concatePrefix(p string) string {
+func (n ResId) concatPrefix(p string) string {
 	if p == "" {
 		return n.prefix
 	}
@@ -123,9 +124,5 @@ func (n ResId) concatePrefix(p string) string {
 }
 
 func (n ResId) prefixList() []string {
-	var plist []string
-	if n.prefix == "" {
-		return plist
-	}
 	return strings.Split(n.prefix, ":")
 }