diff --git a/src/transformState.js b/src/transformState.js
index a1eaa0640..ce7a6c2c2 100644
--- a/src/transformState.js
+++ b/src/transformState.js
@@ -5,7 +5,36 @@
  * @param {Object[]} actions
  */
 function transformState(state, actions) {
-  // write code here
+  const TYPE_ONE = 'addProperties';
+  const TYPE_TWO = 'removeProperties';
+  const TYPE_THREE = 'clear';
+
+  for (const obj of actions) {
+    const { type } = obj;
+
+    switch (type) {
+      case TYPE_ONE:
+        Object.assign(state, obj.extraData);
+        break;
+
+      case TYPE_TWO:
+        for (const key of obj.keysToRemove) {
+          delete state[key];
+        }
+        break;
+
+      case TYPE_THREE:
+        for (const prop in state) {
+          delete state[prop];
+        }
+        break;
+
+      default:
+        return state;
+    }
+  }
+
+  return state;
 }
 
 module.exports = transformState;