Solution

src/transformStateWithClones.js

@@ -6,8 +6,65 @@
  *
  * @return {Object[]}
  */
+
 function transformStateWithClones(state, actions) {
-  // write code here
+  const hystoryArray = [];
+  const stateCopy = { ...state };
+
+  for (const action of actions) {
+    const newCopy = Object.assign({}, hystoryArray[hystoryArray.length - 1]);
+
+    switch (action.type) {
+      case 'addProperties':
+        if (hystoryArray.length >= 1) {
+          hystoryArray.push(addProperties(newCopy, action.extraData));
+          break;
+        } else {
+          hystoryArray.push(addProperties(stateCopy, action.extraData));
+          break;
+        }
+
+      case 'removeProperties':
+        if (hystoryArray.length >= 1) {
+          hystoryArray.push(removeProperties(newCopy, action.keysToRemove));
+          break;
+        } else {
+          hystoryArray.push(removeProperties(stateCopy, action.keysToRemove));
+          break;
+        }
+
+      case 'clear':
+        if (hystoryArray.length >= 1) {
+          hystoryArray.push(clearProperties(newCopy));
+          break;
+        } else {
+          hystoryArray.push(clearProperties(stateCopy));
+          break;
+        }
+    }
+  }
+
+  function addProperties(stateCopyObject, extraData) {
+    return Object.assign(stateCopyObject, extraData);
+  }
+
+  function removeProperties(stateCopyObject, keysToRemove) {
+    for (const key of keysToRemove) {
+      delete stateCopyObject[key];
+    }
+
+    return stateCopyObject;
+  }
+
+  function clearProperties(stateCopyObject) {
+    for (const key in stateCopyObject) {
+      delete stateCopyObject[key];
+    }
+
+    return stateCopyObject;
+  }
+
+  return hystoryArray;
 }
 
 module.exports = transformStateWithClones;