fix: workaround itty-router issue with cached responses

owid · Dec 19, 2024 · 62e4ec6 · 62e4ec6
1 parent db220f1
commit 62e4ec6
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Showing 3 changed files with 18 additions and 3 deletions.
diff --git a/functions/explorers/[slug].ts b/functions/explorers/[slug].ts
@@ -21,7 +21,12 @@ const router = Router<
     [URL, Env, Etag, EventContext<unknown, any, Record<string, unknown>>]
 >({
     before: [preflight],
-    finally: [corsify],
+    finally: [
+        // This is a workaround for a bug in itty-router; without this, we would get 500 errors with
+        // "Can't modify immutable headers." for requests served from cache.
+        // see https://github.com/kwhitley/itty-router/issues/242#issuecomment-2194227007
+        (resp: Response) => corsify(new Response(resp.body, resp)),
+    ],
 })
 router
     .get(

diff --git a/functions/grapher/[slug].ts b/functions/grapher/[slug].ts
@@ -25,7 +25,12 @@ const router = Router<
     [URL, Env, Etag, EventContext<unknown, any, Record<string, unknown>>]
 >({
     before: [preflight],
-    finally: [corsify],
+    finally: [
+        // This is a workaround for a bug in itty-router; without this, we would get 500 errors with
+        // "Can't modify immutable headers." for requests served from cache.
+        // see https://github.com/kwhitley/itty-router/issues/242#issuecomment-2194227007
+        (resp: Response) => corsify(new Response(resp.body, resp)),
+    ],
 })
 router
     .get(

diff --git a/functions/grapher/by-uuid/[uuid].ts b/functions/grapher/by-uuid/[uuid].ts
@@ -9,7 +9,12 @@ const { preflight, corsify } = cors({
 
 const router = Router<IRequestStrict, [URL, Env, string]>({
     before: [preflight],
-    finally: [corsify],
+    finally: [
+        // This is a workaround for a bug in itty-router; without this, we would get 500 errors with
+        // "Can't modify immutable headers." for requests served from cache.
+        // see https://github.com/kwhitley/itty-router/issues/242#issuecomment-2194227007
+        (resp: Response) => corsify(new Response(resp.body, resp)),
+    ],
 })
 
 router