From a6842852414111e2e1e300f8c752725c1361f6e7 Mon Sep 17 00:00:00 2001
From: Michal Piechowiak <misiek.piechowiak@gmail.com>
Date: Tue, 23 Jan 2024 17:49:43 +0100
Subject: [PATCH 1/2] perf: use must-revalidate cache-control header as common
 and only create header routes for routes with different cache-control

---
 packages/gatsby/src/utils/adapter/manager.ts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/packages/gatsby/src/utils/adapter/manager.ts b/packages/gatsby/src/utils/adapter/manager.ts
index fbe10be215dd0..0178da120c4f9 100644
--- a/packages/gatsby/src/utils/adapter/manager.ts
+++ b/packages/gatsby/src/utils/adapter/manager.ts
@@ -308,7 +308,7 @@ const headersAreEqual = (a, b): boolean =>
 const getDefaultHeaderRoutes = (pathPrefix: string): HeaderRoutes => [
   {
     path: `${pathPrefix}/*`,
-    headers: BASE_HEADERS,
+    headers: MUST_REVALIDATE_HEADERS,
   },
   {
     path: `${pathPrefix}/static/*`,
@@ -319,7 +319,7 @@ const getDefaultHeaderRoutes = (pathPrefix: string): HeaderRoutes => [
 const customHeaderFilter =
   (route: Route, pathPrefix: string) =>
   (h: IHeader["headers"][0]): boolean => {
-    for (const baseHeader of BASE_HEADERS) {
+    for (const baseHeader of MUST_REVALIDATE_HEADERS) {
       if (headersAreEqual(baseHeader, h)) {
         return false
       }

From 604b42530e11a9db387b7aa65b6c7106cb45a146 Mon Sep 17 00:00:00 2001
From: Michal Piechowiak <misiek.piechowiak@gmail.com>
Date: Tue, 23 Jan 2024 18:23:58 +0100
Subject: [PATCH 2/2] test: update headerRoutes unit tests

---
 .../__tests__/__snapshots__/manager.ts.snap   | 67 ++-----------------
 .../src/utils/adapter/__tests__/manager.ts    | 26 +++----
 2 files changed, 12 insertions(+), 81 deletions(-)

diff --git a/packages/gatsby/src/utils/adapter/__tests__/__snapshots__/manager.ts.snap b/packages/gatsby/src/utils/adapter/__tests__/__snapshots__/manager.ts.snap
index 293ef0f4e01c5..467d6ebd73252 100644
--- a/packages/gatsby/src/utils/adapter/__tests__/__snapshots__/manager.ts.snap
+++ b/packages/gatsby/src/utils/adapter/__tests__/__snapshots__/manager.ts.snap
@@ -359,6 +359,10 @@ exports[`getRoutesManifest should return routes manifest 2`] = `
 Array [
   Object {
     "headers": Array [
+      Object {
+        "key": "cache-control",
+        "value": "public, max-age=0, must-revalidate",
+      },
       Object {
         "key": "x-xss-protection",
         "value": "1; mode=block",
@@ -387,42 +391,6 @@ Array [
     ],
     "path": "/static/*",
   },
-  Object {
-    "headers": Array [
-      Object {
-        "key": "cache-control",
-        "value": "public, max-age=0, must-revalidate",
-      },
-    ],
-    "path": "/",
-  },
-  Object {
-    "headers": Array [
-      Object {
-        "key": "cache-control",
-        "value": "public, max-age=0, must-revalidate",
-      },
-    ],
-    "path": "/page-data/index/page-data.json",
-  },
-  Object {
-    "headers": Array [
-      Object {
-        "key": "cache-control",
-        "value": "public, max-age=0, must-revalidate",
-      },
-    ],
-    "path": "/page-data/sq/d/1.json",
-  },
-  Object {
-    "headers": Array [
-      Object {
-        "key": "cache-control",
-        "value": "public, max-age=0, must-revalidate",
-      },
-    ],
-    "path": "/page-data/app-data.json",
-  },
   Object {
     "headers": Array [
       Object {
@@ -432,32 +400,5 @@ Array [
     ],
     "path": "/app-123.js",
   },
-  Object {
-    "headers": Array [
-      Object {
-        "key": "cache-control",
-        "value": "public, max-age=0, must-revalidate",
-      },
-    ],
-    "path": "/chunk-map.json",
-  },
-  Object {
-    "headers": Array [
-      Object {
-        "key": "cache-control",
-        "value": "public, max-age=0, must-revalidate",
-      },
-    ],
-    "path": "/webpack.stats.json",
-  },
-  Object {
-    "headers": Array [
-      Object {
-        "key": "cache-control",
-        "value": "public, max-age=0, must-revalidate",
-      },
-    ],
-    "path": "/_gatsby/slices/_gatsby-scripts-1.html",
-  },
 ]
 `;
diff --git a/packages/gatsby/src/utils/adapter/__tests__/manager.ts b/packages/gatsby/src/utils/adapter/__tests__/manager.ts
index 348a6cb442667..d506c3b4eee98 100644
--- a/packages/gatsby/src/utils/adapter/__tests__/manager.ts
+++ b/packages/gatsby/src/utils/adapter/__tests__/manager.ts
@@ -156,6 +156,10 @@ describe(`getRoutesManifest`, () => {
 
     expect(headers).toContainEqual({
       headers: [
+        {
+          key: `cache-control`,
+          value: `public, max-age=0, must-revalidate`,
+        },
         { key: `x-xss-protection`, value: `1; mode=block` },
         { key: `x-content-type-options`, value: `nosniff` },
         { key: `referrer-policy`, value: `same-origin` },
@@ -172,15 +176,6 @@ describe(`getRoutesManifest`, () => {
       ],
       path: `/static/*`,
     })
-    expect(headers).toContainEqual({
-      headers: [
-        {
-          key: `cache-control`,
-          value: `public, max-age=0, must-revalidate`,
-        },
-      ],
-      path: `/page-data/index/page-data.json`,
-    })
     expect(headers).toContainEqual({
       headers: [
         {
@@ -234,6 +229,10 @@ describe(`getRoutesManifest`, () => {
 
     expect(headers).toContainEqual({
       headers: [
+        {
+          key: `cache-control`,
+          value: `public, max-age=0, must-revalidate`,
+        },
         { key: `x-xss-protection`, value: `1; mode=block` },
         { key: `x-content-type-options`, value: `nosniff` },
         { key: `referrer-policy`, value: `same-origin` },
@@ -250,15 +249,6 @@ describe(`getRoutesManifest`, () => {
       ],
       path: `/prefix/static/*`,
     })
-    expect(headers).toContainEqual({
-      headers: [
-        {
-          key: `cache-control`,
-          value: `public, max-age=0, must-revalidate`,
-        },
-      ],
-      path: `/prefix/page-data/index/page-data.json`,
-    })
     expect(headers).toContainEqual({
       headers: [
         {