moby/layer/empty_test.go
chchliang c72112b171 add testcase in layer/empty_test.go with Metadata()
Signed-off-by: chchliang <chen.chuanliang@zte.com.cn>
2017-09-15 14:13:48 +08:00

52 lines
1.2 KiB
Go

package layer
import (
"io"
"testing"
"github.com/opencontainers/go-digest"
)
func TestEmptyLayer(t *testing.T) {
if EmptyLayer.ChainID() != ChainID(DigestSHA256EmptyTar) {
t.Fatal("wrong ChainID for empty layer")
}
if EmptyLayer.DiffID() != DigestSHA256EmptyTar {
t.Fatal("wrong DiffID for empty layer")
}
if EmptyLayer.Parent() != nil {
t.Fatal("expected no parent for empty layer")
}
if size, err := EmptyLayer.Size(); err != nil || size != 0 {
t.Fatal("expected zero size for empty layer")
}
if diffSize, err := EmptyLayer.DiffSize(); err != nil || diffSize != 0 {
t.Fatal("expected zero diffsize for empty layer")
}
meta, err := EmptyLayer.Metadata()
if len(meta) != 0 || err != nil {
t.Fatal("expected zero length metadata for empty layer")
}
tarStream, err := EmptyLayer.TarStream()
if err != nil {
t.Fatalf("error streaming tar for empty layer: %v", err)
}
digester := digest.Canonical.Digester()
_, err = io.Copy(digester.Hash(), tarStream)
if err != nil {
t.Fatalf("error hashing empty tar layer: %v", err)
}
if digester.Digest() != digest.Digest(DigestSHA256EmptyTar) {
t.Fatal("empty layer tar stream hashes to wrong value")
}
}