Add a workaround to prevent retrieving removed documents from MemDB

server/backend/backend.go

@@ -118,7 +118,7 @@ func New(
 	}
 
 	logging.DefaultLogger().Infof(
-		"backend created: id: %s, rpc: %s: db: %s",
+		"backend created: id: %s, rpc: %s",
 		serverInfo.ID,
 		dbInfo,
 	)

server/backend/database/memory/database.go

@@ -631,7 +631,20 @@ func (d *DB) FindDocInfoByKeyAndOwner(
 	txn := d.db.Txn(true)
 	defer txn.Abort()
 
-	raw, err := txn.First(tblDocuments, "project_id_key_removed_at", projectID.String(), key.String(), gotime.Time{})
+	// TODO(hackerwins): Removed documents should be filtered out by the query, but
+	// somehow it does not work. This is a workaround.
+	// val, err := txn.First(tblDocuments, "project_id_key_removed_at", projectID.String(), key.String(), gotime.Time{})
+	iter, err := txn.Get(tblDocuments, "project_id_key_removed_at", projectID.String(), key.String(), gotime.Time{})
+	if err != nil {
+		return nil, fmt.Errorf("find document by key: %w", err)
+	}
+	var raw interface{}
+	for val := iter.Next(); val != nil; val = iter.Next() {
+		if val != nil && val.(*database.DocInfo).RemovedAt.IsZero() {
+			raw = val
+		}
+	}
+
 	if err != nil {
 		return nil, fmt.Errorf("find document by key: %w", err)
 	}

server/backend/database/testcases/testcases.go

@@ -148,8 +148,6 @@ func RunFindDocInfosByQueryTest(
 			keys = append(keys, info.Key.String())
 		}
 
-		// sort.Strings(keys)
-
 		assert.EqualValues(t, []string{
 			"test", "test abc", "test$0", "test$3", "test-search",
 			"test0", "test1", "test10", "test11", "test2"}, keys)
@@ -627,49 +625,41 @@ func RunFindDocInfosByPagingTest(t *testing.T, db database.Database, projectID t
 func RunCreateChangeInfosTest(t *testing.T, db database.Database, projectID types.ID) {
 	t.Run("set RemovedAt in docInfo test", func(t *testing.T) {
 		ctx := context.Background()
-		docKey := key.Key(fmt.Sprintf("tests$%s", t.Name()))
+		docKey := helper.TestDocKey(t)
 
+		// 01. Create a client and a document then attach the document to the client.
 		clientInfo, _ := db.ActivateClient(ctx, projectID, t.Name())
 		docInfo, _ := db.FindDocInfoByKeyAndOwner(ctx, projectID, clientInfo.ID, docKey, true)
 		assert.NoError(t, clientInfo.AttachDocument(docInfo.ID))
 		assert.NoError(t, db.UpdateClientInfoAfterPushPull(ctx, clientInfo, docInfo))
 
-		doc := document.New(key.Key(t.Name()))
-		pack := doc.CreateChangePack()
-
-		// Set RemovedAt in docInfo and store changes
-		err := db.CreateChangeInfos(ctx, projectID, docInfo, 0, pack.Changes, true)
+		// 02. Remove the document and check the document is removed.
+		err := db.CreateChangeInfos(ctx, projectID, docInfo, 0, []*change.Change{}, true)
 		assert.NoError(t, err)
-
-		// Check whether RemovedAt is set in docInfo
 		docInfo, err = db.FindDocInfoByID(ctx, projectID, docInfo.ID)
 		assert.NoError(t, err)
 		assert.Equal(t, false, docInfo.RemovedAt.IsZero())
 	})
 
 	t.Run("reuse same key to create docInfo test ", func(t *testing.T) {
 		ctx := context.Background()
-		docKey := key.Key(fmt.Sprintf("tests$%s", t.Name()))
+		docKey := helper.TestDocKey(t)
 
+		// 01. Create a client and a document then attach the document to the client.
 		clientInfo1, _ := db.ActivateClient(ctx, projectID, t.Name())
 		docInfo1, _ := db.FindDocInfoByKeyAndOwner(ctx, projectID, clientInfo1.ID, docKey, true)
 		assert.NoError(t, clientInfo1.AttachDocument(docInfo1.ID))
 		assert.NoError(t, db.UpdateClientInfoAfterPushPull(ctx, clientInfo1, docInfo1))
 
-		doc := document.New(key.Key(t.Name()))
-		pack := doc.CreateChangePack()
-
-		// Set RemovedAt in docInfo and store changes
-		err := db.CreateChangeInfos(ctx, projectID, docInfo1, 0, pack.Changes, true)
+		// 02. Remove the document.
+		assert.NoError(t, clientInfo1.RemoveDocument(docInfo1.ID))
+		err := db.CreateChangeInfos(ctx, projectID, docInfo1, 0, []*change.Change{}, true)
 		assert.NoError(t, err)
 
-		// Use same key to create docInfo
-		clientInfo2, _ := db.ActivateClient(ctx, projectID, t.Name())
-		docInfo2, _ := db.FindDocInfoByKeyAndOwner(ctx, projectID, clientInfo2.ID, docKey, true)
-		assert.NoError(t, clientInfo2.AttachDocument(docInfo2.ID))
-		assert.NoError(t, db.UpdateClientInfoAfterPushPull(ctx, clientInfo2, docInfo2))
-
-		// Check they have same key but different id
+		// 03. Create a document with same key and check they have same key but different id.
+		docInfo2, _ := db.FindDocInfoByKeyAndOwner(ctx, projectID, clientInfo1.ID, docKey, true)
+		assert.NoError(t, clientInfo1.AttachDocument(docInfo2.ID))
+		assert.NoError(t, db.UpdateClientInfoAfterPushPull(ctx, clientInfo1, docInfo2))
 		assert.Equal(t, docInfo1.Key, docInfo2.Key)
 		assert.NotEqual(t, docInfo1.ID, docInfo2.ID)
 	})