add task solution

README.md

@@ -22,4 +22,4 @@ Make the `App` a class component with `pressedKey` in the `state`.
 - Implement a solution following the [React task guideline](https://github.com/mate-academy/react_task-guideline#react-tasks-guideline).
 - Use the [React TypeScript cheat sheet](https://mate-academy.github.io/fe-program/js/extra/react-typescript).
 - Open one more terminal and run tests with `npm test` to ensure your solution is correct.
-- Replace `<your_account>` with your Github username in the [DEMO LINK](https://<your_account>.github.io/react_keyboard/) and add it to the PR description.
+- Replace `<your_account>` with your Github username in the [DEMO LINK](https://wasik07.github.io/react_keyboard/) and add it to the PR description.

src/App.tsx

@@ -1,7 +1,31 @@
-import React from 'react';
+import React, { useEffect, useRef, useState } from 'react';
 
-export const App: React.FC = () => (
-  <div className="App">
-    <p className="App__message">The last pressed key is [Enter]</p>
-  </div>
-);
+export const App: React.FC = () => {
+  const [pressedKey, setPressedKey] = useState('');
+
+  const lastKey = useRef('');
+
+  useEffect(() => {
+    const handleKeyUp = (event: KeyboardEvent) => {
+      setPressedKey(lastKey.current !== event.key ? event.key : pressedKey);
+
+      lastKey.current = event.key;
+    };
+
+    document.addEventListener('keyup', handleKeyUp);
+
+    return () => {
+      document.removeEventListener('keyup', handleKeyUp);
+    };
+  }, [pressedKey]);
+
+  return (
+    <div className="App">
+      <p className="App__message">
+        {pressedKey
+          ? `The last pressed key is [${pressedKey}]`
+          : 'Nothing was pressed yet'}
+      </p>
+    </div>
+  );
+};