test: add e2e specs covering oras tag (oras-project#718)

Resolves oras-project#717

Signed-off-by: Billy Zha <jinzha1@microsoft.com>

test/e2e/suite/auth/auth.go

@@ -33,6 +33,7 @@ var _ = Describe("Common registry user", Ordered, func() {
 			RunWithoutLogin("push", "-a", "key=value", Host+"/repo:tag")
 			RunWithoutLogin("pull", Host+"/repo:tag")
 			RunWithoutLogin("manifest", "fetch", Host+"/repo:tag")
+			RunWithoutLogin("tag", Host+"/repo:tag", "tag1")
 			RunWithoutLogin("repo", "ls", Host)
 			RunWithoutLogin("repo", "tags", Reference(Host, "repo", ""))
 			RunWithoutLogin("manifest", "fetch-config", Host+"/repo:tag")

test/e2e/suite/command/tag.go

@@ -0,0 +1,57 @@
+/*
+Copyright The ORAS Authors.
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+http://www.apache.org/licenses/LICENSE-2.0
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package command
+
+import (
+	"fmt"
+
+	. "github.com/onsi/ginkgo/v2"
+	. "oras.land/oras/test/e2e/internal/utils"
+)
+
+var repoFmt = fmt.Sprintf("command/tag/%%s/%d/%%s", GinkgoRandomSeed())
+
+var _ = Describe("ORAS beginners:", func() {
+	When("running repo command", func() {
+		runAndShowPreviewInHelp([]string{"tag"})
+		It("should fail when no manifest reference provided", func() {
+			ORAS("tag").WithFailureCheck().MatchErrKeyWords("Error:").Exec()
+		})
+
+		It("should fail when provided manifest reference is not found", func() {
+			ORAS("tag", Reference(Host, repo, "i-dont-think-this-tag-exists")).WithFailureCheck().MatchErrKeyWords("Error:").Exec()
+		})
+	})
+})
+
+var _ = Describe("Common registry users:", func() {
+	var tagAndValidate = func(reg string, repo string, tagOrDigest string, tags ...string) {
+		ORAS(append([]string{"tag", Reference(reg, repo, tagOrDigest)}, tags...)...).MatchKeyWords(tags...).Exec()
+		ORAS("repo", "tags", Reference(reg, repo, "")).MatchKeyWords(tags...).Exec()
+	}
+	When("running `tag`", func() {
+		It("should add a tag to an existent manifest when providing tag reference", func() {
+			tagAndValidate(Host, repo, multiImage, "tag-via-tag")
+		})
+		It("should add a tag to an existent manifest when providing digest reference", func() {
+			tagAndValidate(Host, repo, digest_multi, "tag-via-digest")
+		})
+		It("should add multiple tags to an existent manifest when providing digest reference", func() {
+			tagAndValidate(Host, repo, digest_multi, "tag1-via-digest", "tag2-via-digest", "tag3-via-digest")
+		})
+		It("should add multiple tags to an existent manifest when providing tag reference", func() {
+			tagAndValidate(Host, repo, multiImage, "tag1-via-tag", "tag1-via-tag", "tag1-via-tag")
+		})
+	})
+})