make task solution

src/transformState.js

@@ -5,7 +5,28 @@
  * @param {Object[]} actions
  */
 function transformState(state, actions) {
-  // write code here
+  actions.forEach(action => {
+    switch (action.type) {
+      case 'clear': for (const key in state) {
+        delete state[key];
+      };
+        break;
+
+      case 'addProperties': Object.assign(state, action.extraData);
+        break;
+
+      case 'removeProperties': action.keysToRemove.forEach(key => {
+        if (state.hasOwnProperty(key)) {
+          delete state[key];
+        }
+      });
+        break;
+
+      default: return 'Fix mistake';
+    }
+  });
+
+  return state;
 }
 
 module.exports = transformState;