From 15730f43cdeac447f7991e9d071bf041ae7d493f Mon Sep 17 00:00:00 2001
From: Johannes Dillmann <j.dillmann@sap.com>
Date: Fri, 31 Jan 2025 13:10:12 +0100
Subject: [PATCH] Expose IndexManifest

Signed-off-by: Johannes Dillmann <j.dillmann@sap.com>
---
 cnb_index.go         |  4 ++
 fakes/image_index.go | 99 ++++++++++++++++++++++++++++++++++++++++++++
 index.go             |  1 +
 3 files changed, 104 insertions(+)
 create mode 100644 fakes/image_index.go

diff --git a/cnb_index.go b/cnb_index.go
index 5045f2f7..92877a4a 100644
--- a/cnb_index.go
+++ b/cnb_index.go
@@ -123,6 +123,10 @@ func (h *CNBIndex) Annotations(digest name.Digest) (annotations map[string]strin
 	return desc.Annotations, nil
 }
 
+func (h *CNBIndex) IndexManifest() (*v1.IndexManifest, error) {
+	return getIndexManifest(h.ImageIndex)
+}
+
 // setters
 
 func (h *CNBIndex) SetAnnotations(digest name.Digest, annotations map[string]string) (err error) {
diff --git a/fakes/image_index.go b/fakes/image_index.go
new file mode 100644
index 00000000..a0abec08
--- /dev/null
+++ b/fakes/image_index.go
@@ -0,0 +1,99 @@
+package fakes
+
+import (
+	"github.com/buildpacks/imgutil"
+	"github.com/google/go-containerregistry/pkg/name"
+	v1 "github.com/google/go-containerregistry/pkg/v1"
+)
+
+var _ imgutil.ImageIndex = ImageIndex{}
+
+type ImageIndex struct {
+	Manifests []v1.Descriptor
+}
+
+// AddManifest implements imgutil.ImageIndex.
+func (i ImageIndex) AddManifest(_ v1.Image) {
+	panic("unimplemented")
+}
+
+// Annotations implements imgutil.ImageIndex.
+func (i ImageIndex) Annotations(_ name.Digest) (map[string]string, error) {
+	panic("unimplemented")
+}
+
+// Architecture implements imgutil.ImageIndex.
+func (i ImageIndex) Architecture(_ name.Digest) (string, error) {
+	panic("unimplemented")
+}
+
+// DeleteDir implements imgutil.ImageIndex.
+func (i ImageIndex) DeleteDir() error {
+	panic("unimplemented")
+}
+
+// Inspect implements imgutil.ImageIndex.
+func (i ImageIndex) Inspect() (string, error) {
+	panic("unimplemented")
+}
+
+// OS implements imgutil.ImageIndex.
+func (i ImageIndex) OS(_ name.Digest) (string, error) {
+	panic("unimplemented")
+}
+
+// OSFeatures implements imgutil.ImageIndex.
+func (i ImageIndex) OSFeatures(_ name.Digest) ([]string, error) {
+	panic("unimplemented")
+}
+
+// OSVersion implements imgutil.ImageIndex.
+func (i ImageIndex) OSVersion(_ name.Digest) (string, error) {
+	panic("unimplemented")
+}
+
+// Push implements imgutil.ImageIndex.
+func (i ImageIndex) Push(_ ...imgutil.IndexOption) error {
+	panic("unimplemented")
+}
+
+// RemoveManifest implements imgutil.ImageIndex.
+func (i ImageIndex) RemoveManifest(_ name.Digest) error {
+	panic("unimplemented")
+}
+
+// SaveDir implements imgutil.ImageIndex.
+func (i ImageIndex) SaveDir() error {
+	panic("unimplemented")
+}
+
+// SetAnnotations implements imgutil.ImageIndex.
+func (i ImageIndex) SetAnnotations(_ name.Digest, _ map[string]string) error {
+	panic("unimplemented")
+}
+
+// SetArchitecture implements imgutil.ImageIndex.
+func (i ImageIndex) SetArchitecture(_ name.Digest, _ string) error {
+	panic("unimplemented")
+}
+
+// SetOS implements imgutil.ImageIndex.
+func (i ImageIndex) SetOS(_ name.Digest, _ string) error {
+	panic("unimplemented")
+}
+
+// SetVariant implements imgutil.ImageIndex.
+func (i ImageIndex) SetVariant(_ name.Digest, _ string) error {
+	panic("unimplemented")
+}
+
+// Variant implements imgutil.ImageIndex.
+func (i ImageIndex) Variant(_ name.Digest) (string, error) {
+	panic("unimplemented")
+}
+
+func (i ImageIndex) IndexManifest() (*v1.IndexManifest, error) {
+	return &v1.IndexManifest{
+		Manifests: i.Manifests,
+	}, nil
+}
diff --git a/index.go b/index.go
index 532fc585..04910a7f 100644
--- a/index.go
+++ b/index.go
@@ -28,6 +28,7 @@ type ImageIndex interface {
 	Inspect() (string, error)
 	AddManifest(image v1.Image)
 	RemoveManifest(digest name.Digest) error
+	IndexManifest() (*v1.IndexManifest, error)
 
 	Push(ops ...IndexOption) error
 	SaveDir() error