1 files changed, 57 insertions, 0 deletions
diff --git a/entity/dag/operation_testing.go b/entity/dag/operation_testing.go
new file mode 100644
index 00000000..29923eec
--- /dev/null
+++ b/entity/dag/operation_testing.go
@@ -0,0 +1,57 @@
+package dag
+
+import (
+	"encoding/json"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+
+	"github.com/MichaelMure/git-bug/entity"
+	"github.com/MichaelMure/git-bug/identity"
+	"github.com/MichaelMure/git-bug/repository"
+)
+
+// SerializeRoundTripTest realize a marshall/unmarshall round-trip in the same condition as with OperationPack,
+// and check if the recovered operation is identical.
+func SerializeRoundTripTest[OpT Operation](t *testing.T, maker func(author identity.Interface, unixTime int64) OpT) {
+	repo := repository.NewMockRepo()
+
+	rene, err := identity.NewIdentity(repo, "René Descartes", "rene@descartes.fr")
+	require.NoError(t, err)
+
+	op := maker(rene, time.Now().Unix())
+	// enforce having an id
+	op.Id()
+
+	rdt := &roundTripper[OpT]{Before: op, author: rene}
+
+	data, err := json.Marshal(rdt)
+	require.NoError(t, err)
+
+	err = json.Unmarshal(data, &rdt)
+	require.NoError(t, err)
+
+	require.Equal(t, op, rdt.after)
+}
+
+type roundTripper[OpT Operation] struct {
+	Before OpT
+	author identity.Interface
+	after  OpT
+}
+
+func (r *roundTripper[OpT]) MarshalJSON() ([]byte, error) {
+	return json.Marshal(r.Before)
+}
+
+func (r *roundTripper[OpT]) UnmarshalJSON(data []byte) error {
+	if err := json.Unmarshal(data, &r.after); err != nil {
+		return err
+	}
+	// Set the id from the serialized data
+	r.after.setId(entity.DeriveId(data))
+	// Set the author, as OperationPack would do
+	r.after.setAuthor(r.author)
+	return nil
+}