From e34a5a11fae4ceaae01d274d53a2b72fb5e3bc7a Mon Sep 17 00:00:00 2001
From: Xiaoxuan Wang <xiaoxuanwang@microsoft.com>
Date: Tue, 14 Jan 2025 10:11:40 +0800
Subject: [PATCH] apply metadata render interface to oras discover command

Signed-off-by: Xiaoxuan Wang <xiaoxuanwang@microsoft.com>
---
 cmd/oras/internal/display/metadata/interface.go        |  4 ++--
 cmd/oras/internal/display/metadata/json/discover.go    |  4 ++--
 cmd/oras/internal/display/metadata/table/discover.go   |  4 ++--
 .../internal/display/metadata/template/discover.go     |  4 ++--
 cmd/oras/internal/display/metadata/tree/discover.go    |  4 ++--
 cmd/oras/root/discover.go                              | 10 +++++-----
 6 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/cmd/oras/internal/display/metadata/interface.go b/cmd/oras/internal/display/metadata/interface.go
index cc8d504c0..8815a0500 100644
--- a/cmd/oras/internal/display/metadata/interface.go
+++ b/cmd/oras/internal/display/metadata/interface.go
@@ -42,13 +42,13 @@ type AttachHandler interface {
 
 // DiscoverHandler handles metadata output for discover events.
 type DiscoverHandler interface {
+	Renderer
+
 	// MultiLevelSupported returns true if the handler supports multi-level
 	// discovery.
 	MultiLevelSupported() bool
 	// OnDiscovered is called after a referrer is discovered.
 	OnDiscovered(referrer, subject ocispec.Descriptor) error
-	// OnCompleted is called when referrer discovery is completed.
-	OnCompleted() error
 }
 
 // ManifestFetchHandler handles metadata output for manifest fetch events.
diff --git a/cmd/oras/internal/display/metadata/json/discover.go b/cmd/oras/internal/display/metadata/json/discover.go
index 8d9eea230..fa1c24e0e 100644
--- a/cmd/oras/internal/display/metadata/json/discover.go
+++ b/cmd/oras/internal/display/metadata/json/discover.go
@@ -57,7 +57,7 @@ func (h *discoverHandler) OnDiscovered(referrer, subject ocispec.Descriptor) err
 	return nil
 }
 
-// OnCompleted implements metadata.DiscoverHandler.
-func (h *discoverHandler) OnCompleted() error {
+// Render implements metadata.DiscoverHandler.
+func (h *discoverHandler) Render() error {
 	return output.PrintPrettyJSON(h.out, model.NewDiscover(h.path, h.referrers))
 }
diff --git a/cmd/oras/internal/display/metadata/table/discover.go b/cmd/oras/internal/display/metadata/table/discover.go
index 6acd0e6e8..d76967fd0 100644
--- a/cmd/oras/internal/display/metadata/table/discover.go
+++ b/cmd/oras/internal/display/metadata/table/discover.go
@@ -59,8 +59,8 @@ func (h *discoverHandler) OnDiscovered(referrer, subject ocispec.Descriptor) err
 	return nil
 }
 
-// OnCompleted implements metadata.DiscoverHandler.
-func (h *discoverHandler) OnCompleted() error {
+// Render implements metadata.DiscoverHandler.
+func (h *discoverHandler) Render() error {
 	if n := len(h.referrers); n > 1 {
 		fmt.Fprintln(h.out, "Discovered", n, "artifacts referencing", h.rawReference)
 	} else {
diff --git a/cmd/oras/internal/display/metadata/template/discover.go b/cmd/oras/internal/display/metadata/template/discover.go
index 1495a4b03..8ce7581ae 100644
--- a/cmd/oras/internal/display/metadata/template/discover.go
+++ b/cmd/oras/internal/display/metadata/template/discover.go
@@ -59,7 +59,7 @@ func (h *discoverHandler) OnDiscovered(referrer, subject ocispec.Descriptor) err
 	return nil
 }
 
-// OnCompleted implements metadata.DiscoverHandler.
-func (h *discoverHandler) OnCompleted() error {
+// Render implements metadata.DiscoverHandler.
+func (h *discoverHandler) Render() error {
 	return output.ParseAndWrite(h.out, model.NewDiscover(h.path, h.referrers), h.template)
 }
diff --git a/cmd/oras/internal/display/metadata/tree/discover.go b/cmd/oras/internal/display/metadata/tree/discover.go
index 496de1279..0738a6597 100644
--- a/cmd/oras/internal/display/metadata/tree/discover.go
+++ b/cmd/oras/internal/display/metadata/tree/discover.go
@@ -78,7 +78,7 @@ func (h *discoverHandler) OnDiscovered(referrer, subject ocispec.Descriptor) err
 	return nil
 }
 
-// OnCompleted implements metadata.DiscoverHandler.
-func (h *discoverHandler) OnCompleted() error {
+// Render implements metadata.DiscoverHandler.
+func (h *discoverHandler) Render() error {
 	return tree.NewPrinter(h.out).Print(h.root)
 }
diff --git a/cmd/oras/root/discover.go b/cmd/oras/root/discover.go
index e65817b57..cd2c36b1d 100644
--- a/cmd/oras/root/discover.go
+++ b/cmd/oras/root/discover.go
@@ -132,12 +132,12 @@ func runDiscover(cmd *cobra.Command, opts *discoverOptions) error {
 		return err
 	}
 
-	handler, err := display.NewDiscoverHandler(opts.Printer, opts.Format, opts.Path, opts.RawReference, desc, opts.verbose)
+	metadataHandler, err := display.NewDiscoverHandler(opts.Printer, opts.Format, opts.Path, opts.RawReference, desc, opts.verbose)
 	if err != nil {
 		return err
 	}
-	if handler.MultiLevelSupported() {
-		if err := fetchAllReferrers(ctx, repo, desc, opts.artifactType, handler); err != nil {
+	if metadataHandler.MultiLevelSupported() {
+		if err := fetchAllReferrers(ctx, repo, desc, opts.artifactType, metadataHandler); err != nil {
 			return err
 		}
 	} else {
@@ -146,12 +146,12 @@ func runDiscover(cmd *cobra.Command, opts *discoverOptions) error {
 			return err
 		}
 		for _, ref := range refs {
-			if err := handler.OnDiscovered(ref, desc); err != nil {
+			if err := metadataHandler.OnDiscovered(ref, desc); err != nil {
 				return err
 			}
 		}
 	}
-	return handler.OnCompleted()
+	return metadataHandler.Render()
 }
 
 func fetchAllReferrers(ctx context.Context, repo oras.ReadOnlyGraphTarget, desc ocispec.Descriptor, artifactType string, handler metadata.DiscoverHandler) error {