Provide header rules distinctly from page rules for adapters

packages/gatsby/src/utils/adapter/__tests__/manager.ts

@@ -50,7 +50,7 @@ describe(`getRoutesManifest`, () => {
     process.chdir(fixturesDir)
     setWebpackAssets(new Set([`app-123.js`]))
 
-    const routesManifest = getRoutesManifest()
+    const { routes: routesManifest } = getRoutesManifest()
 
     expect(routesManifest).toMatchSnapshot()
   })
@@ -62,7 +62,7 @@ describe(`getRoutesManifest`, () => {
     process.chdir(fixturesDir)
     setWebpackAssets(new Set([`app-123.js`]))
 
-    const routesManifest = getRoutesManifest()
+    const { routes: routesManifest } = getRoutesManifest()
 
     expect(routesManifest).toEqual(
       expect.arrayContaining([
@@ -81,7 +81,7 @@ describe(`getRoutesManifest`, () => {
     process.chdir(fixturesDir)
     setWebpackAssets(new Set([`app-123.js`]))
 
-    const routesManifest = getRoutesManifest()
+    const { routes: routesManifest } = getRoutesManifest()
 
     expect(routesManifest).toEqual(
       expect.arrayContaining([
@@ -92,6 +92,57 @@ describe(`getRoutesManifest`, () => {
       ])
     )
   })
+
+  it(`should return header rules`, () => {
+    mockStoreState(stateDefault, {
+      config: { ...stateDefault.config, trailingSlash: `always` },
+    })
+    process.chdir(fixturesDir)
+    setWebpackAssets(new Set([`app-123.js`, `static/app-456.js`]))
+
+    const { headers } = getRoutesManifest()
+
+    expect(headers).toContainEqual({
+      headers: [
+        { key: "x-xss-protection", value: "1; mode=block" },
+        { key: "x-content-type-options", value: "nosniff" },
+        { key: "referrer-policy", value: "same-origin" },
+        { key: "x-frame-options", value: "DENY" },
+      ],
+      path: "/*",
+    })
+    expect(headers).toContainEqual({
+      headers: [
+        {
+          key: "cache-control",
+          value: "public, max-age=31536000, immutable",
+        },
+      ],
+      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: [
+        {
+          key: "cache-control",
+          value: "public, max-age=31536000, immutable",
+        },
+      ],
+      path: "/app-123.js",
+    })
+
+    expect(headers).not.toContain(
+      expect.objectContaining({ path: "/static/app-456.js" })
+    )
+  })
 })
 
 describe(`getFunctionsManifest`, () => {

packages/gatsby/src/utils/adapter/manager.ts

@@ -17,6 +17,7 @@ import type {
   IAdapter,
   IAdapterFinalConfig,
   IAdapterConfig,
+  HeaderRoutes,
 } from "./types"
 import { store, readState } from "../../redux"
 import { getPageMode } from "../page-mode"
@@ -201,10 +202,13 @@ export async function initAdapterManager(): Promise<IAdapterManager> {
 
       let _routesManifest: RoutesManifest | undefined = undefined
       let _functionsManifest: FunctionsManifest | undefined = undefined
+      let _headerRoutes: HeaderRoutes | undefined = undefined
       const adaptContext: IAdaptContext = {
         get routesManifest(): RoutesManifest {
           if (!_routesManifest) {
-            _routesManifest = getRoutesManifest()
+            const { routes, headers } = getRoutesManifest()
+            _routesManifest = routes
+            _headerRoutes = headers
           }
 
           return _routesManifest
@@ -216,6 +220,15 @@ export async function initAdapterManager(): Promise<IAdapterManager> {
 
           return _functionsManifest
         },
+        get headerRoutes(): HeaderRoutes {
+          if (!_headerRoutes) {
+            const { routes, headers } = getRoutesManifest()
+            _routesManifest = routes
+            _headerRoutes = headers
+          }
+
+          return _headerRoutes
+        },
         reporter,
         // Our internal Gatsby config allows this to be undefined but for the adapter we should always pass through the default values and correctly show this in the TypeScript types
         trailingSlash: trailingSlash as TrailingSlash,
@@ -261,11 +274,40 @@ export function setWebpackAssets(assets: Set<string>): void {
 
 type RouteWithScore = { score: number } & Route
 
-function getRoutesManifest(): RoutesManifest {
+const defaultHeaderRoutes: HeaderRoutes = [
+  {
+    path: "/*",
+    headers: BASE_HEADERS,
+  },
+  {
+    path: "/static/*",
+    headers: PERMAMENT_CACHING_HEADERS.filter(h => !BASE_HEADERS.includes(h)),
+  },
+]
+
+const customHeaderFilter = (route: Route) => (h: IHeader["headers"][0]) => {
+  if (BASE_HEADERS.includes(h)) {
+    return false
+  }
+  if (
+    route.path.startsWith(`/static/`) &&
+    PERMAMENT_CACHING_HEADERS.includes(h)
+  ) {
+    return false
+  }
+  return true
+}
+
+function getRoutesManifest(): {
+  routes: RoutesManifest
+  headers: HeaderRoutes
+} {
   const routes: Array<RouteWithScore> = []
   const state = store.getState()
   const createHeaders = createHeadersMatcher(state.config.headers)
 
+  const headerRoutes: HeaderRoutes = [...defaultHeaderRoutes]
+
   const fileAssets = new Set(
     globSync(`**/**`, {
       cwd: posix.join(process.cwd(), `public`),
@@ -290,11 +332,18 @@ function getRoutesManifest(): RoutesManifest {
 
     if (route.type !== `function`) {
       route.headers = createHeaders(route.path, route.headers)
+      const customHeaders = route.headers.filter(customHeaderFilter(route))
+      if (customHeaders.length > 0) {
+        headerRoutes.push({ path: route.path, headers: customHeaders })
+      }
     }
 
-    ;(route as RouteWithScore).score = rankRoute(route.path)
+    const routeWithScore: RouteWithScore = {
+      ...route,
+      score: rankRoute(route.path),
+    }
 
-    routes.push(route as RouteWithScore)
+    routes.push(routeWithScore)
   }
 
   function addStaticRoute({
@@ -506,25 +555,27 @@ function getRoutesManifest(): RoutesManifest {
     })
   }
 
-  return (
-    routes
-      .sort((a, b) => {
-        // The higher the score, the higher the specificity of our path
-        const order = b.score - a.score
-        if (order !== 0) {
-          return order
-        }
+  const sortedRoutes = routes
+    .sort((a, b) => {
+      // The higher the score, the higher the specificity of our path
+      const order = b.score - a.score
+      if (order !== 0) {
+        return order
+      }
 
-        // if specificity is the same we do lexigraphic comparison of path to ensure
-        // deterministic order regardless of order pages where created
-        return a.path.localeCompare(b.path)
-      })
-      // The score should be internal only, so we remove it from the final manifest
-      // eslint-disable-next-line @typescript-eslint/no-unused-vars
-      .map(({ score, ...rest }): Route => {
-        return { ...rest }
-      })
-  )
+      // if specificity is the same we do lexigraphic comparison of path to ensure
+      // deterministic order regardless of order pages where created
+      return a.path.localeCompare(b.path)
+    })
+    // The score should be internal only, so we remove it from the final manifest
+    // eslint-disable-next-line @typescript-eslint/no-unused-vars
+    .map(({ score, ...rest }): Route => {
+      return { ...rest }
+    })
+  return {
+    routes: sortedRoutes,
+    headers: headerRoutes,
+  }
 }
 
 function getFunctionsManifest(): FunctionsManifest {

packages/gatsby/src/utils/adapter/types.ts

@@ -67,6 +67,12 @@ export type Route = IStaticRoute | IFunctionRoute | IRedirectRoute
 
 export type RoutesManifest = Array<Route>
 
+export interface HeaderRoute extends IBaseRoute {
+  headers: IHeader["headers"]
+}
+
+export type HeaderRoutes = HeaderRoute[]
+
 export interface IFunctionDefinition {
   /**
    * Unique identifier of this function. Corresponds to the `functionId` inside the `routesManifest`.
@@ -99,6 +105,7 @@ interface IDefaultContext {
 export interface IAdaptContext extends IDefaultContext {
   routesManifest: RoutesManifest
   functionsManifest: FunctionsManifest
+  headerRoutes: HeaderRoutes
   /**
    * @see https://www.gatsbyjs.com/docs/reference/config-files/gatsby-config/#pathprefix
    */