set max-age=0 when you want no cache (#31657)

middleware/cache-control.js

@@ -26,6 +26,7 @@ export function cacheControlFactory(
     maxAge && immutable && 'immutable',
     !maxAge && 'private',
     !maxAge && 'no-store',
+    maxAge === 0 && 'max-age=0',
   ]
     .filter(Boolean)
     .join(', ')

tests/rendering/server.js

@@ -9,6 +9,7 @@ import { SURROGATE_ENUMS } from '../../middleware/set-fastly-surrogate-key.js'
 import { getPathWithoutVersion } from '../../lib/path-utils.js'
 import { describe, jest } from '@jest/globals'
 
+const NO_CACHE_CONTROL = 'private, no-store, max-age=0'
 const AZURE_STORAGE_URL = 'githubdocs.azureedge.net'
 const activeProducts = Object.values(productMap).filter(
   (product) => !product.wip && !product.hidden
@@ -606,7 +607,7 @@ describe('server', () => {
       expect(res.statusCode).toBe(302)
       expect(res.headers['set-cookie']).toBeUndefined()
       // no cache control because a language prefix had to be injected
-      expect(res.headers['cache-control']).toBe('private, no-store')
+      expect(res.headers['cache-control']).toBe(NO_CACHE_CONTROL)
     })
 
     test('redirects old articles to their slugified URL', async () => {
@@ -620,7 +621,7 @@ describe('server', () => {
       const res = await get('/')
       expect(res.statusCode).toBe(302)
       expect(res.headers.location).toBe('/en')
-      expect(res.headers['cache-control']).toBe('private, no-store')
+      expect(res.headers['cache-control']).toBe(NO_CACHE_CONTROL)
       expect(res.headers['set-cookie']).toBeUndefined()
     })
 
@@ -639,7 +640,7 @@ describe('server', () => {
 
       expect(res.statusCode).toBe(302)
       expect(res.headers.location).toBe('/en')
-      expect(res.headers['cache-control']).toBe('private, no-store')
+      expect(res.headers['cache-control']).toBe(NO_CACHE_CONTROL)
       expect(res.headers['set-cookie']).toBeUndefined()
     })
 
@@ -653,7 +654,7 @@ describe('server', () => {
       })
       expect(res.statusCode).toBe(302)
       expect(res.headers.location).toBe('/en')
-      expect(res.headers['cache-control']).toBe('private, no-store')
+      expect(res.headers['cache-control']).toBe(NO_CACHE_CONTROL)
       expect(res.headers['set-cookie']).toBeUndefined()
     })
 
@@ -663,7 +664,7 @@ describe('server', () => {
       expect(res.headers.location.startsWith('/en/')).toBe(true)
       expect(res.headers['set-cookie']).toBeUndefined()
       // no cache control because a language prefix had to be injected
-      expect(res.headers['cache-control']).toBe('private, no-store')
+      expect(res.headers['cache-control']).toBe(NO_CACHE_CONTROL)
     })
 
     test('redirects that not only injects /en/ should have cache-control', async () => {

tests/routing/deprecated-enterprise-versions.js

@@ -4,6 +4,8 @@ import enterpriseServerReleases from '../../lib/enterprise-server-releases.js'
 import { get, getDOM } from '../helpers/e2etest.js'
 import { SURROGATE_ENUMS } from '../../middleware/set-fastly-surrogate-key.js'
 
+const NO_CACHE_CONTROL = 'private, no-store, max-age=0'
+
 jest.useFakeTimers({ legacyFakeTimers: true })
 
 describe('enterprise deprecation', () => {
@@ -96,7 +98,7 @@ describe('recently deprecated redirects', () => {
     expect(res.headers.location).toBe('/en/enterprise-server@3.0')
     expect(res.headers['set-cookie']).toBeUndefined()
     // Deliberately no cache control because it is user-dependent
-    expect(res.headers['cache-control']).toBe('private, no-store')
+    expect(res.headers['cache-control']).toBe(NO_CACHE_CONTROL)
   })
 
   test('already languaged enterprise 3.0 redirects', async () => {
@@ -115,7 +117,7 @@ describe('recently deprecated redirects', () => {
     expect(res.statusCode).toBe(302)
     expect(res.headers['set-cookie']).toBeUndefined()
     // Deliberately no cache control because it is user-dependent
-    expect(res.headers['cache-control']).toBe('private, no-store')
+    expect(res.headers['cache-control']).toBe(NO_CACHE_CONTROL)
     // This is based on
     // https://github.com/github/help-docs-archived-enterprise-versions/blob/master/3.0/redirects.json
     expect(res.headers.location).toBe(

tests/routing/redirects.js

@@ -126,7 +126,7 @@ describe('redirects', () => {
       const res = await get('/')
       expect(res.statusCode).toBe(302)
       expect(res.headers.location).toBe('/en')
-      expect(res.headers['cache-control']).toBe('private, no-store')
+      expect(res.headers['cache-control']).toBe('private, no-store, max-age=0')
     })
 
     test('trailing slash on languaged homepage should permantently redirect', async () => {

tests/translations/redirects.js

@@ -2,6 +2,8 @@ import { languageKeys } from '../../lib/languages.js'
 import { get } from '../helpers/e2etest.js'
 import { PREFERRED_LOCALE_COOKIE_NAME } from '../../lib/constants.js'
 
+const NO_CACHE_CONTROL = 'private, no-store, max-age=0'
+
 const langs = languageKeys.filter((lang) => lang !== 'en')
 
 describe('redirects', () => {
@@ -12,7 +14,7 @@ describe('redirects', () => {
     })
     expect(res.statusCode).toBe(302)
     expect(res.headers.location).toBe(`/${lang}/get-started`)
-    expect(res.headers['cache-control']).toBe('private, no-store')
+    expect(res.headers['cache-control']).toBe(NO_CACHE_CONTROL)
     expect(res.headers['set-cookie']).toBeUndefined()
   })
 
@@ -26,7 +28,7 @@ describe('redirects', () => {
     })
     expect(res.statusCode).toBe(302)
     expect(res.headers.location).toBe(`/${lang}/get-started`)
-    expect(res.headers['cache-control']).toBe('private, no-store')
+    expect(res.headers['cache-control']).toBe(NO_CACHE_CONTROL)
     expect(res.headers['set-cookie']).toBeUndefined()
   })