fix cache control for fully-static pages router page

Author: conico974

packages/open-next/src/core/routing/util.ts

@@ -243,7 +243,11 @@ export function fixCacheHeaderForHtmlPages(
   const localizedPath = localizePath(internalEvent);
   // WORKAROUND: `NextServer` does not set cache headers for HTML pages
   // https://opennext.js.org/aws/v2/advanced/workaround#workaround-nextserver-does-not-set-cache-headers-for-html-pages
-  if (HtmlPages.includes(localizedPath)) {
+  // We need to not cache if the request contains an `x-middleware-prefetch` header
+  if (
+    HtmlPages.includes(localizedPath) &&
+    !internalEvent.headers["x-middleware-prefetch"]
+  ) {
     headers[CommonHeaders.CACHE_CONTROL] =
       "public, max-age=0, s-maxage=31536000, must-revalidate";
   }

packages/tests-unit/tests/core/routing/util.test.ts

@@ -487,6 +487,7 @@ describe("fixCacheHeaderForHtmlPages", () => {
     fixCacheHeaderForHtmlPages(
       {
         rawPath: "/my-html-page",
+        headers: {},
       },
       headers,
     );
@@ -496,6 +497,23 @@ describe("fixCacheHeaderForHtmlPages", () => {
     );
   });
 
+  it("should not add cache-control header for html page but with an `x-middleware-prefetch` header", () => {
+    const headers: Record<string, string> = {};
+    config.HtmlPages.push("/my-html-page");
+
+    fixCacheHeaderForHtmlPages(
+      {
+        rawPath: "/my-html-page",
+        headers: {
+          "x-middleware-prefetch": "1",
+        },
+      },
+      headers,
+    );
+
+    expect(headers).not.toHaveProperty("cache-control");
+  });
+
   it("should not add cache-control header for non html page", () => {
     const headers: Record<string, string> = {};