fix: verify hosting response content types

scripts/verify-hosting-headers.mjs

@@ -15,13 +15,13 @@ let mode;
 if (baseUrl) {
   mode = "live";
   const assets = await readdir("dist/assets");
-  const hashedAsset = assets.find((file) => !file.endsWith(".map"));
-  if (!hashedAsset) throw new Error("No built hashed asset found.");
+  const hashedJavaScript = assets.find((file) => file.endsWith(".js"));
+  if (!hashedJavaScript) throw new Error("No built hashed JavaScript found.");
   const paths = {
     index: "/",
     runtimeConfig: "/config.json",
     releaseManifest: "/release-manifest.json",
-    hashedAsset: `/assets/${hashedAsset}`,
+    hashedAsset: `/assets/${hashedJavaScript}`,
   };
   responses = {};
   for (const [surface, pathname] of Object.entries(paths)) {
@@ -51,6 +51,18 @@ for (const [surface, policy] of Object.entries(cachePolicy.surfaces)) {
     observed,
     passed: observed === policy.cacheControl,
   });
+  const observedContentType = responses[surface]?.["content-type"];
+  const observedMime = observedContentType
+    ?.split(";", 1)[0]
+    .trim()
+    .toLowerCase();
+  results.push({
+    surface,
+    header: "content-type",
+    expected: policy.contentTypes,
+    observed: observedContentType,
+    passed: policy.contentTypes.includes(observedMime),
+  });
   if (policy.securityHeaders) {
     for (const [header, expected] of Object.entries(securityPolicy.headers)) {
       const observedSecurity = responses[surface]?.[header.toLowerCase()];
@@ -100,7 +112,9 @@ await writeFile(
 );
 
 if (!passed) {
-  process.stderr.write("Hosting cache/security header verification failed.\n");
+  process.stderr.write(
+    "Hosting cache/content-type/security header verification failed.\n",
+  );
   process.exit(1);
 }
 process.stdout.write(