solution

src/transformState.js

@@ -1,11 +1,36 @@
-'use strict';
+"use strict";
 
-/**
- * @param {Object} state
- * @param {Object[]} actions
- */
 function transformState(state, actions) {
-  // write code here
+  for (const action of actions) {
+    const { type } = action;
+
+    switch (type) {
+      case "addProperties":
+        const { extraData } = action;
+        if (extraData) {
+          Object.assign(state, extraData);
+        }
+        break;
+
+      case "removeProperties":
+        const { keysToRemove } = action;
+        if (keysToRemove) {
+          for (const key of keysToRemove) {
+            delete state[key];
+          }
+        }
+        break;
+
+      case "clear":
+        Object.keys(state).forEach((key) => {
+          delete state[key];
+        });
+        break;
+
+      default:
+        break;
+    }
+  }
 }
 
 module.exports = transformState;