fix(gatsby): Adapter header rules

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

@@ -146,7 +146,7 @@ Array [
   },
   Object {
     "functionId": "static-index-js",
-    "path": "/api/static/",
+    "path": "/api/static",
     "type": "function",
   },
   Object {
@@ -233,7 +233,7 @@ Array [
   Object {
     "cache": true,
     "functionId": "ssr-engine",
-    "path": "/dsg/",
+    "path": "/dsg",
     "type": "function",
   },
   Object {
@@ -263,7 +263,7 @@ Array [
   },
   Object {
     "functionId": "ssr-engine",
-    "path": "/ssr/",
+    "path": "/ssr",
     "type": "function",
   },
   Object {

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([
@@ -98,14 +98,87 @@ describe(`getRoutesManifest`, () => {
     process.chdir(fixturesDir)
     setWebpackAssets(new Set([`app-123.js`]))
 
-    const routesManifest = getRoutesManifest()
-    expect(routesManifest).toEqual(
+    const { routes } = getRoutesManifest()
+    expect(routes).toEqual(
       expect.arrayContaining([
         expect.objectContaining({ path: `https://old-url` }),
         expect.objectContaining({ path: `http://old-url` }),
       ])
     )
   })
+
+  it(`should return header rules`, () => {
+    mockStoreState(stateDefault, {
+      config: {
+        ...stateDefault.config,
+        headers: [
+          {
+            source: `/ssr/*`,
+            headers: [
+              {
+                key: `x-ssr-header`,
+                value: `my custom header value from config`,
+              },
+            ],
+          },
+        ],
+      },
+    })
+    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.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: `/ssr/*`,
+    })
+
+    expect(headers).not.toContain(
+      expect.objectContaining({ path: `/static/app-456.js` })
+    )
+  })
 })
 
 describe(`getFunctionsManifest`, () => {

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

@@ -27,10 +27,14 @@ export const MUST_REVALIDATE_HEADERS: IHeader["headers"] = [
   ...BASE_HEADERS,
 ]
 
-export const PERMAMENT_CACHING_HEADERS: IHeader["headers"] = [
+export const PERMANENT_CACHE_CONTROL_HEADER: IHeader["headers"] = [
   {
     key: `cache-control`,
     value: `public, max-age=31536000, immutable`,
   },
+]
+
+export const PERMAMENT_CACHING_HEADERS: IHeader["headers"] = [
+  ...PERMANENT_CACHE_CONTROL_HEADER,
   ...BASE_HEADERS,
 ]

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"
@@ -31,6 +32,7 @@ import {
   BASE_HEADERS,
   MUST_REVALIDATE_HEADERS,
   PERMAMENT_CACHING_HEADERS,
+  PERMANENT_CACHE_CONTROL_HEADER,
 } from "./constants"
 import { createHeadersMatcher } from "./create-headers"
 import { HTTP_STATUS_CODE } from "../../redux/types"
@@ -201,10 +203,13 @@ 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 +221,15 @@ 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 +275,48 @@ export function setWebpackAssets(assets: Set<string>): void {
 
 type RouteWithScore = { score: number } & Route
 
-function getRoutesManifest(): RoutesManifest {
+const headersAreEqual = (a, b): boolean =>
+  a.key === b.key && a.value === b.value
+
+const defaultHeaderRoutes: HeaderRoutes = [
+  {
+    path: `/*`,
+    headers: BASE_HEADERS,
+  },
+  {
+    path: `/static/*`,
+    headers: PERMANENT_CACHE_CONTROL_HEADER,
+  },
+]
+
+const customHeaderFilter =
+  (route: Route) =>
+  (h: IHeader["headers"][0]): boolean => {
+    for (const baseHeader of BASE_HEADERS) {
+      if (headersAreEqual(baseHeader, h)) {
+        return false
+      }
+    }
+    if (route.path.startsWith(`/static/`)) {
+      for (const cachingHeader of PERMAMENT_CACHING_HEADERS) {
+        if (headersAreEqual(cachingHeader, 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`),
@@ -293,11 +344,18 @@ 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({
@@ -509,25 +567,27 @@ 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 +67,11 @@ export type Route = IStaticRoute | IFunctionRoute | IRedirectRoute
 
 export type RoutesManifest = Array<Route>
 
+export interface IHeaderRoute extends IBaseRoute {
+  headers: IHeader["headers"]
+}
+
+export type HeaderRoutes = Array<IHeaderRoute>
 export interface IFunctionDefinition {
   /**
    * Unique identifier of this function. Corresponds to the `functionId` inside the `routesManifest`.
@@ -99,6 +104,7 @@ 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
    */