fail computing manifest if no refs are provided (#887)

* fail computing digest if no refs are provided * fix error string
google · Dec 30, 2020 · ec3c7a5 · ec3c7a5
1 parent 6544cb0
commit ec3c7a5
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Showing 2 changed files with 16 additions and 0 deletions.
diff --git a/pkg/v1/tarball/write.go b/pkg/v1/tarball/write.go
@@ -222,6 +222,10 @@ func writeImagesToTar(refToImage map[name.Reference]v1.Image, m []byte, size int
 func calculateManifest(refToImage map[name.Reference]v1.Image) (m Manifest, err error) {
 	imageToTags := dedupRefToImage(refToImage)
 
+	if len(imageToTags) == 0 {
+		return nil, errors.New("set of images is empty")
+	}
+
 	for img, tags := range imageToTags {
 		cfgName, err := img.ConfigName()
 		if err != nil {

diff --git a/pkg/v1/tarball/write_test.go b/pkg/v1/tarball/write_test.go
@@ -461,6 +461,18 @@ func TestComputeManifest(t *testing.T) {
 	}
 }
 
+func TestComputeManifest_FailsOnNoRefs(t *testing.T) {
+	_, err := tarball.ComputeManifest(nil)
+	if err == nil || !strings.Contains(err.Error(), "set of images is empty") {
+		t.Error("expected calculateManifest to fail with nil input")
+	}
+
+	_, err = tarball.ComputeManifest(map[name.Reference]v1.Image{})
+	if err == nil || !strings.Contains(err.Error(), "set of images is empty") {
+		t.Error("expected calculateManifest to fail with empty input")
+	}
+}
+
 func getLayersHashes(img v1.Image) ([]string, error) {
 	hashes := []string{}
 	layers, err := img.Layers()