fix: ignore --pretty when --output is used for oras manifest fetch (o…

…ras-project#1363)

Signed-off-by: Xiaoxuan Wang <[email protected]>

cmd/oras/root/manifest/fetch.go

@@ -74,8 +74,11 @@ Example - Fetch raw manifest from an OCI layout archive file 'layout.tar':
 			switch {
 			case opts.outputPath == "-" && opts.Template != "":
 				return fmt.Errorf("`--output -` cannot be used with `--format %s` at the same time", opts.Template)
-			case opts.OutputDescriptor && opts.outputPath == "-":
+			case opts.outputPath == "-" && opts.OutputDescriptor:
 				return fmt.Errorf("`--descriptor` cannot be used with `--output -` at the same time")
+			// ignore --pretty when output to a file
+			case opts.outputPath != "" && opts.outputPath != "-":
+				opts.Pretty.Pretty = false
 			}
 			if err := oerrors.CheckMutuallyExclusiveFlags(cmd.Flags(), "format", "pretty"); err != nil {
 				return err

test/e2e/suite/command/manifest.go

@@ -232,6 +232,13 @@ var _ = Describe("1.1 registry users:", func() {
 			MatchFile(fetchPath, multi_arch.Manifest, DefaultTimeout)
 		})
 
+		It("should ignore --pretty when fetching manifest to a file", func() {
+			fetchPath := filepath.Join(GinkgoT().TempDir(), "fetchedImage")
+			ORAS("manifest", "fetch", RegistryRef(ZOTHost, ImageRepo, multi_arch.Tag), "--output", fetchPath, "--pretty").
+				Exec()
+			MatchFile(fetchPath, multi_arch.Manifest, DefaultTimeout)
+		})
+
 		It("should fetch manifest to file and output json", func() {
 			fetchPath := filepath.Join(GinkgoT().TempDir(), "fetchedImage")
 			digest := multi_arch.LinuxAMD64.Digest.String()