Set updated_at with created_at when creating Document (#977)

This commit ensures that when a new Document is created and attached,
the updated_at field is properly initialized with the created_at.

Prior to commit b494fa2, the updated_at field was correctly set
during the attachment process through a push-pull operation that
involved presence. However, after that commit, the updated_at field is
no longer updated when a document is attached, resulting in
inconsistencies.

server/backend/database/memory/database.go

@@ -746,6 +746,7 @@ func (d *DB) FindDocInfoByKeyAndOwner(
 			Owner:      clientRefKey.ClientID,
 			ServerSeq:  0,
 			CreatedAt:  now,
+			UpdatedAt:  now,
 			AccessedAt: now,
 		}
 		if err := txn.Insert(tblDocuments, info); err != nil {

server/backend/database/mongo/client.go

@@ -739,8 +739,9 @@ func (c *Client) FindDocInfoByKeyAndOwner(
 				"owner":      clientRefKey.ClientID,
 				"server_seq": 0,
 				"created_at": now,
+				"updated_at": now,
 			},
-		})
+		}, options.FindOneAndUpdate().SetReturnDocument(options.After))
 	} else {
 		result = c.collection(ColDocuments).FindOne(ctx, filter)
 		if result.Err() == mongo.ErrNoDocuments {

server/backend/database/testcases/testcases.go

@@ -948,6 +948,9 @@ func RunCreateChangeInfosTest(t *testing.T, db database.Database, projectID type
 		// 01. Create a client and a document then attach the document to the client.
 		clientInfo, _ := db.ActivateClient(ctx, projectID, t.Name())
 		docInfo1, _ := db.FindDocInfoByKeyAndOwner(ctx, clientInfo.RefKey(), docKey, true)
+		assert.Equal(t, docInfo1.Owner, clientInfo.ID)
+		assert.NotEqual(t, gotime.Date(1, gotime.January, 1, 0, 0, 0, 0, gotime.UTC), docInfo1.UpdatedAt)
+		assert.Equal(t, docInfo1.CreatedAt, docInfo1.UpdatedAt)
 		docRefKey := docInfo1.RefKey()
 		assert.NoError(t, clientInfo.AttachDocument(docRefKey.DocID, false))
 		assert.NoError(t, db.UpdateClientInfoAfterPushPull(ctx, clientInfo, docInfo1))
@@ -957,7 +960,7 @@ func RunCreateChangeInfosTest(t *testing.T, db database.Database, projectID type
 		doc := document.New(key.Key(t.Name()))
 		doc.SetActor(actorID)
 
-		// 02. update document only presence
+		// 02. Update document only presence
 		assert.NoError(t, doc.Update(func(root *json.Object, p *presence.Presence) error {
 			p.Set("key", "val")
 			return nil
@@ -968,7 +971,7 @@ func RunCreateChangeInfosTest(t *testing.T, db database.Database, projectID type
 		docInfo2, _ := db.FindDocInfoByKeyAndOwner(ctx, clientInfo.RefKey(), docKey, true)
 		assert.Equal(t, updatedAt, docInfo2.UpdatedAt)
 
-		// 03. update document presence and operation
+		// 03. Update document presence and operation
 		assert.NoError(t, doc.Update(func(root *json.Object, p *presence.Presence) error {
 			p.Set("key", "val")
 			root.SetNewArray("array")