From cc6dace0bfc79ccb5248699de5ba3ca8b801d321 Mon Sep 17 00:00:00 2001 From: Hyunbin Seo <47051820+hyunbinseo@users.noreply.github.com> Date: Wed, 22 Jan 2025 16:04:23 +0900 Subject: [PATCH] docs: handle immutable headers error (#12543) * docs: handle immutable headers error * Update documentation/docs/30-advanced/20-hooks.md Co-authored-by: Simon H <5968653+dummdidumm@users.noreply.github.com> --------- Co-authored-by: Tee Ming Co-authored-by: Simon H <5968653+dummdidumm@users.noreply.github.com> --- documentation/docs/30-advanced/20-hooks.md | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/documentation/docs/30-advanced/20-hooks.md b/documentation/docs/30-advanced/20-hooks.md index a0f7a36c79c3..b35e66b73a09 100644 --- a/documentation/docs/30-advanced/20-hooks.md +++ b/documentation/docs/30-advanced/20-hooks.md @@ -67,6 +67,13 @@ export async function handle({ event, resolve }) { event.locals.user = await getUserInformation(event.cookies.get('sessionid')); const response = await resolve(event); + + // Note that modifying response headers isn't always safe. + // Response objects can have immutable headers + // (e.g. Response.redirect() returned from an endpoint). + // Modifying immutable headers throws a TypeError. + // In that case, clone the response or avoid creating a + // response object with immutable headers. response.headers.set('x-custom-header', 'potato'); return response;