Solution

src/transformStateWithClones.js

@@ -7,7 +7,40 @@
  * @return {Object[]}
  */
 function transformStateWithClones(state, actions) {
-  // write code here
+  let currentState = { ...state };
+  const states = [];
+
+  for (const action of actions) {
+    switch (action.type) {
+      case 'addProperties':
+        currentState = { ...currentState, ...action.extraData };
+        break;
+
+      case 'removeProperties':
+        currentState = removeProperties(currentState, action.keysToRemove);
+        break;
+
+      case 'clear':
+        currentState = {};
+        break;
+
+      default:
+        break;
+    }
+    states.push(currentState);
+  }
+
+  return states;
+}
+
+function removeProperties(state, keysToRemove) {
+  const newState = { ...state };
+
+  for (const key of keysToRemove) {
+    delete newState[key];
+  }
+
+  return newState;
 }
 
 module.exports = transformStateWithClones;