1 files changed, 61 insertions, 0 deletions
diff --git a/pkg/crane/digest_test.go b/pkg/crane/digest_test.go
new file mode 100644
index 0000000..ac215d3
--- /dev/null
+++ b/pkg/crane/digest_test.go
@@ -0,0 +1,61 @@
+// Copyright 2021 Google LLC All Rights Reserved.
+//
+// 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 crane
+
+import (
+	"fmt"
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"testing"
+
+	"github.com/google/go-containerregistry/pkg/v1/types"
+)
+
+func TestDigest_MissingDigest(t *testing.T) {
+	response := []byte("doesn't matter")
+	digest := "sha256:477c34d98f9e090a4441cf82d2f1f03e64c8eb730e8c1ef39a8595e685d4df65" // Digest of "doesn't matter"
+	getCalled := false
+
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Path == "/v2/" {
+			w.WriteHeader(http.StatusOK)
+			return
+		}
+		w.Header().Set("Content-Type", string(types.DockerManifestSchema2))
+		if r.Method == http.MethodGet {
+			getCalled = true
+			w.Header().Set("Docker-Content-Digest", digest)
+		}
+		// This will automatically set the Content-Length header.
+		w.Write(response)
+	}))
+	defer server.Close()
+	u, err := url.Parse(server.URL)
+	if err != nil {
+		t.Fatalf("url.Parse(%v) = %v", server.URL, err)
+	}
+
+	got, err := Digest(fmt.Sprintf("%s/repo:latest", u.Host))
+	if err != nil {
+		t.Fatalf("Digest: %v", err)
+	}
+	if got != digest {
+		t.Errorf("Digest: got %q, want %q", got, digest)
+	}
+	if !getCalled {
+		t.Errorf("Digest: expected GET to be called")
+	}
+}