test: improve coverage for resolve

Signed-off-by: Sajay Antony <sajaya@microsoft.com>

test/e2e/internal/utils/testdata.go

@@ -22,6 +22,7 @@ const (
 	BlobRepo     = "command/blobs"
 	ArtifactRepo = "command/artifacts"
 	Namespace    = "command"
+	InvalidRepo  = "INVALID"
 	// env
 	RegHostKey         = "ORAS_REGISTRY_HOST"
 	FallbackRegHostKey = "ORAS_REGISTRY_FALLBACK_HOST"

test/e2e/suite/command/resolve.go

@@ -31,6 +31,12 @@ var _ = Describe("ORAS beginners:", func() {
 		It("should fail when no manifest reference provided", func() {
 			ORAS("resolve").ExpectFailure().MatchErrKeyWords("Error:").Exec()
 		})
+		It("should fail when when repo is invalid", func() {
+			ORAS("resolve", fmt.Sprintf("%s/%s", ZOTHost, InvalidRepo)).ExpectFailure().MatchErrKeyWords("Error:", fmt.Sprintf("invalid reference: invalid repository %q", InvalidRepo)).Exec()
+		})
+		It("should fail when no tag or digest provided", func() {
+			ORAS("resolve", RegistryRef(ZOTHost, ImageRepo, "")).ExpectFailure().MatchErrKeyWords("Error:", "no tag or digest when expecting <name:tag|name@digest>").Exec()
+		})
 		It("should fail when provided manifest reference is not found", func() {
 			ORAS("resolve", RegistryRef(ZOTHost, ImageRepo, "i-dont-think-this-tag-exists")).ExpectFailure().MatchErrKeyWords("Error: failed to resolve digest:", "not found").Exec()
 		})
@@ -39,7 +45,6 @@ var _ = Describe("ORAS beginners:", func() {
 			outString := string(out.Contents())
 			outString = strings.TrimSpace(outString)
 			gomega.Expect(outString).To(gomega.Equal(multi_arch.Digest))
-
 		})
 		It("should resolve with with the fully qualified reference", func() {
 			out := ORAS("resolve", "-l", RegistryRef(ZOTHost, ImageRepo, multi_arch.Tag)).Exec().Out