Adding scope tests for ParseAuthHeader

Signed-off-by: Jacob MacElroy <jacob@okteto.com>

remotes/docker/auth/parse_test.go

@@ -0,0 +1,71 @@
+/*
+   Copyright The containerd 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 auth
+
+import (
+	"fmt"
+	"net/http"
+	"reflect"
+	"testing"
+)
+
+func TestParseAuthHeader(t *testing.T) {
+	headerTemplate := `Bearer realm="%s",service="%s",scope="%s"`
+
+	for _, tc := range []struct {
+		name    string
+		realm   string
+		service string
+		scope   string
+	}{
+		{
+			name:    "SingleScope",
+			realm:   "https://auth.docker.io/token",
+			service: "registry.docker.io",
+			scope:   "repository:foo/bar:pull,push",
+		},
+		{
+			name:    "MultipleScopes",
+			realm:   "https://auth.docker.io/token",
+			service: "registry.docker.io",
+			scope:   "repository:foo/bar:pull,push repository:foo/baz:pull repository:foo/foo:push",
+		},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			expected := []Challenge{
+				{
+					Scheme: BearerAuth,
+					Parameters: map[string]string{
+						"realm":   tc.realm,
+						"service": tc.service,
+						"scope":   tc.scope,
+					},
+				},
+			}
+
+			hdr := http.Header{
+				http.CanonicalHeaderKey("WWW-Authenticate"): []string{fmt.Sprintf(
+					headerTemplate, tc.realm, tc.service, tc.scope,
+				)},
+			}
+			actual := ParseAuthHeader(hdr)
+			if !reflect.DeepEqual(expected, actual) {
+				t.Fatalf("expected %v, but got %v", expected, actual)
+			}
+		})
+	}
+}