update vendor

Signed-off-by: Jess Frazelle <acidburn@microsoft.com>

vendor/github.com/opencontainers/image-spec/identity/chainid_test.go

@@ -0,0 +1,95 @@
+// Copyright 2016 The Linux Foundation
+//
+// 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 identity
+
+import (
+	_ "crypto/sha256" // required to install sha256 digest support
+	"reflect"
+	"testing"
+
+	"github.com/opencontainers/go-digest"
+)
+
+func TestChainID(t *testing.T) {
+	// To provide a good testing base, we define the individual links in a
+	// chain recursively, illustrating the calculations for each chain.
+	//
+	// Note that we use invalid digests for the unmodified identifiers here to
+	// make the computation more readable.
+	chainDigestAB := digest.FromString("sha256:a" + " " + "sha256:b")              // chain for A|B
+	chainDigestABC := digest.FromString(chainDigestAB.String() + " " + "sha256:c") // chain for A|B|C
+
+	for _, testcase := range []struct {
+		Name     string
+		Digests  []digest.Digest
+		Expected []digest.Digest
+	}{
+		{
+			Name: "nil",
+		},
+		{
+			Name:     "empty",
+			Digests:  []digest.Digest{},
+			Expected: []digest.Digest{},
+		},
+		{
+			Name:     "identity",
+			Digests:  []digest.Digest{"sha256:a"},
+			Expected: []digest.Digest{"sha256:a"},
+		},
+		{
+			Name:     "two",
+			Digests:  []digest.Digest{"sha256:a", "sha256:b"},
+			Expected: []digest.Digest{"sha256:a", chainDigestAB},
+		},
+		{
+			Name:     "three",
+			Digests:  []digest.Digest{"sha256:a", "sha256:b", "sha256:c"},
+			Expected: []digest.Digest{"sha256:a", chainDigestAB, chainDigestABC},
+		},
+	} {
+		t.Run(testcase.Name, func(t *testing.T) {
+			t.Log("before", testcase.Digests)
+
+			var ids []digest.Digest
+
+			if testcase.Digests != nil {
+				ids = make([]digest.Digest, len(testcase.Digests))
+				copy(ids, testcase.Digests)
+			}
+
+			ids = ChainIDs(ids)
+			t.Log("after", ids)
+			if !reflect.DeepEqual(ids, testcase.Expected) {
+				t.Errorf("unexpected chain: %v != %v", ids, testcase.Expected)
+			}
+
+			if len(testcase.Digests) == 0 {
+				return
+			}
+
+			// Make sure parent stays stable
+			if ids[0] != testcase.Digests[0] {
+				t.Errorf("parent changed: %v != %v", ids[0], testcase.Digests[0])
+			}
+
+			// make sure that the ChainID function takes the last element
+			id := ChainID(testcase.Digests)
+			if id != ids[len(ids)-1] {
+				t.Errorf("incorrect chain id returned from ChainID: %v != %v", id, ids[len(ids)-1])
+			}
+		})
+	}
+}