diff --git a/packages/core/api/database.js b/packages/core/api/database.js
index 40f03981c..344d62739 100644
--- a/packages/core/api/database.js
+++ b/packages/core/api/database.js
@@ -33,7 +33,7 @@ class Database {
    */
   async addNote(note) {
     if (!note || !note.content || (!note.title && !note.content))
-      return undefined;
+      return undefined; //TODO add test
 
     let timestamp = note.dateCreated || Date.now();
     //add or update a note into the database
@@ -108,6 +108,7 @@ class Database {
     const id = notebook.dateCreated || Date.now();
     let topics = {};
     if (notebook.topics) {
+      //TODO add test
       for (let topic of notebook.topics) {
         topics[topic] = [];
       }
@@ -224,6 +225,7 @@ class Database {
       this.notes[notebookId] = notebook;
       return this.storage.write(KEYS.notebooks, this.notebooks);
     }
+    //TODO add test
     return Promise.resolve();
   }
 
@@ -235,7 +237,7 @@ class Database {
 
   async delete(items, key) {
     if (!items || items.length <= 0 || !this[key] || this[key].length <= 0)
-      return;
+      return; //TODO add test
     for (let item of items) {
       if (this[key].hasOwnProperty(item.dateCreated)) {
         delete this[key][item.dateCreated];
diff --git a/packages/core/helpers/storage.js b/packages/core/helpers/storage.js
index d58b44174..0ff4a5a09 100644
--- a/packages/core/helpers/storage.js
+++ b/packages/core/helpers/storage.js
@@ -12,10 +12,10 @@ class Storage {
     return Convert.fromString(data);
   }
   clear() {
-    this.storage.clear();
+    this.storage.clear(); //TODO add test
   }
   remove(key) {
-    this.storage.remove(key);
+    this.storage.remove(key); //TODO add test
   }
 }
 
diff --git a/packages/core/utils/convert.js b/packages/core/utils/convert.js
index f900f093b..2ece7d329 100644
--- a/packages/core/utils/convert.js
+++ b/packages/core/utils/convert.js
@@ -1,3 +1,4 @@
+//TODO add tests
 export default class Convert {
   static toString(input) {
     try {