solution

package.json

@@ -17,7 +17,7 @@
   "license": "GPL-3.0",
   "devDependencies": {
     "@mate-academy/eslint-config": "latest",
-    "@mate-academy/scripts": "^1.8.6",
+    "@mate-academy/scripts": "^1.9.12",
     "eslint": "^8.57.0",
     "eslint-plugin-jest": "^28.6.0",
     "eslint-plugin-node": "^11.1.0",

src/transformStateWithClones.js

@@ -8,6 +8,40 @@
  */
 function transformStateWithClones(state, actions) {
   // write code here
+  const array = [];
+  const stateCopy = { ...state };
+
+  for (const action of actions) {
+    transform(stateCopy, action);
+  }
+
+  function transform(result, action) {
+    switch (action.type) {
+      case 'addProperties':
+        Object.assign(result, action.extraData);
+        array.push({ ...stateCopy });
+        break;
+
+      case 'removeProperties': {
+        for (const word of action.keysToRemove) {
+          delete stateCopy[word];
+        }
+
+        array.push({ ...stateCopy });
+        break;
+      }
+
+      case 'clear': {
+        for (const key of Object.keys(stateCopy)) {
+          delete stateCopy[key];
+        }
+
+        array.push({ ...stateCopy });
+      }
+    }
+  }
+
+  return array;
 }
 
 module.exports = transformStateWithClones;