feat: add option to useTitle to restore title on un-mount

src/useTitle.ts

@@ -1,11 +1,22 @@
-import { useRef } from 'react';
-
-function useTitle(title: string) {
-  const t = useRef<string>();
-
-  if (t.current !== title) {
-    document.title = t.current = title;
-  }
+import { useRef, useEffect } from 'react';
+export interface UseTitleOptions {
+  restoreOnUnmount?: boolean;
+}
+const DEFAULT_USE_TITLE_OPTIONS: UseTitleOptions = {
+  restoreOnUnmount: false,
+};
+function useTitle(title: string, options: UseTitleOptions = DEFAULT_USE_TITLE_OPTIONS) {
+  const prevTitleRef = useRef(document.title);
+  document.title = title;
+  useEffect(() => {
+    if (options && options.restoreOnUnmount) {
+      return () => {
+        document.title = prevTitleRef.current;
+      };
+    } else {
+      return;
+    }
+  }, []);
 }
 
 export default typeof document !== 'undefined' ? useTitle : (_title: string) => {};

tests/useTitle.test.ts

@@ -13,4 +13,16 @@ describe('useTitle', () => {
     hook.rerender('My other page title');
     expect(document.title).toBe('My other page title');
   });
+
+  it('should restore document title on unmount', () => {
+    renderHook(props => useTitle(props), { initialProps: 'Old Title' });
+    expect(document.title).toBe('Old Title');
+
+    const hook = renderHook(props => useTitle(props.title, { restoreOnUnmount: props.restore }), {
+      initialProps: { title: 'New Title', restore: true },
+    });
+    expect(document.title).toBe('New Title');
+    hook.unmount();
+    expect(document.title).toBe('Old Title');
+  });
 });