Move mock to test package. Add artifacts test

internal/test/test.go

@@ -11,6 +11,7 @@ import (
 	"testing"
 
 	"github.com/docker/attest/pkg/attestation"
+	"github.com/docker/attest/pkg/oci"
 	"github.com/docker/attest/pkg/policy"
 	"github.com/docker/attest/pkg/signerverifier"
 	"github.com/docker/attest/pkg/tlog"
@@ -193,3 +194,32 @@ func ExtractAnnotatedStatements(path string, mediaType string) ([]*AnnotatedStat
 	}
 	return ExtractStatementsFromIndex(mfs, mediaType)
 }
+
+type MockResolver struct {
+	Envs []*attestation.Envelope
+}
+
+func (r MockResolver) Attestations(ctx context.Context, mediaType string) ([]*attestation.Envelope, error) {
+	return r.Envs, nil
+}
+
+func (r MockResolver) ImageName(ctx context.Context) (string, error) {
+	return "library/alpine:latest", nil
+}
+
+func (r MockResolver) ImageDescriptor(ctx context.Context) (*v1.Descriptor, error) {
+	digest, err := v1.NewHash("sha256:da8b190665956ea07890a0273e2a9c96bfe291662f08e2860e868eef69c34620")
+	if err != nil {
+		return nil, err
+	}
+	return &v1.Descriptor{
+		Digest:    digest,
+		Size:      1234,
+		MediaType: "application/vnd.oci.image.manifest.v1+json",
+	}, nil
+
+}
+
+func (r MockResolver) ImagePlatform(ctx context.Context) (*v1.Platform, error) {
+	return oci.ParsePlatform("linux/amd64")
+}