Fix inconsistent handling for /index (#11643)

* Fix inconsistent handling for /index

* Add more test cases

* Add pages/index/index.js test

Co-authored-by: Joe Haddad <joe.haddad@zeit.co>

packages/next/next-server/server/require.ts

@@ -37,7 +37,7 @@ export function getPagePath(
   }
 
   if (!pagesManifest[page]) {
-    const cleanedPage = page.replace(/\/index$/, '') || '/'
+    const cleanedPage = page.replace(/^\/index$/, '') || '/'
     if (!pagesManifest[cleanedPage]) {
       throw pageNotFoundError(page)
     } else {

packages/next/server/lib/find-page-file.ts

@@ -14,8 +14,15 @@ export async function findPageFile(
     const relativePagePath = `${normalizedPagePath}.${extension}`
     const pagePath = join(rootDir, relativePagePath)
 
-    if (await isWriteable(pagePath)) {
-      foundPagePaths.push(relativePagePath)
+    // only /index and /sub/index when /sub/index/index.js is allowed
+    // see test/integration/route-indexes for expected index handling
+    if (
+      normalizedPagePath.startsWith('/index') ||
+      !normalizedPagePath.endsWith('/index')
+    ) {
+      if (await isWriteable(pagePath)) {
+        foundPagePaths.push(relativePagePath)
+      }
     }
 
     const relativePagePathWithIndex = join(

test/integration/client-navigation/test/index.test.js

@@ -52,7 +52,7 @@ describe('Client Navigation', () => {
       '/nav/as-path-using-router',
       '/nav/url-prop-change',
 
-      '/nested-cdm/index',
+      '/nested-cdm',
     ]
     await Promise.all(
       prerender.map(route => renderViaHTTP(context.appPort, route))

test/integration/conflicting-public-file-page/test/index.test.js

@@ -16,7 +16,7 @@ describe('Errors on conflict between public file and page file', () => {
   it('Throws error during development', async () => {
     const appPort = await findPort()
     const app = await launchApp(appDir, appPort)
-    const conflicts = ['/another/conflict', '/another/index', '/hello']
+    const conflicts = ['/another/conflict', '/hello']
 
     for (const conflict of conflicts) {
       const html = await renderViaHTTP(appPort, conflict)

test/integration/custom-server/server.js

@@ -29,7 +29,7 @@ app.prepare().then(() => {
     }
 
     if (/dashboard/.test(req.url)) {
-      return app.render(req, res, '/dashboard/index')
+      return app.render(req, res, '/dashboard')
     }
 
     if (/static\/hello\.text/.test(req.url)) {

test/integration/route-index/pages/index/index.js

@@ -0,0 +1,2 @@
+const page = () => 'hello from index'
+export default page

test/integration/route-index/test/index.test.js

@@ -0,0 +1,60 @@
+/* eslint-env jest */
+/* global jasmine */
+import { join } from 'path'
+import {
+  findPort,
+  launchApp,
+  killApp,
+  nextBuild,
+  nextStart,
+  fetchViaHTTP,
+} from 'next-test-utils'
+
+jasmine.DEFAULT_TIMEOUT_INTERVAL = 1000 * 60 * 2
+
+let app
+let appPort
+const appDir = join(__dirname, '../')
+
+const runTests = () => {
+  it('should handle / correctly', async () => {
+    const res = await fetchViaHTTP(appPort, '/')
+    expect(res.status).toBe(200)
+    expect(await res.text()).toContain('hello from index')
+  })
+
+  it('should handle /index correctly', async () => {
+    const res = await fetchViaHTTP(appPort, '/index')
+    expect(res.status).toBe(200)
+    expect(await res.text()).toContain('hello from index')
+  })
+
+  it('should handle /index/index correctly', async () => {
+    const res = await fetchViaHTTP(appPort, '/index/index')
+    expect(res.status).toBe(404)
+    expect(await res.text()).toContain('page could not be found')
+  })
+}
+
+describe('Route index handling', () => {
+  describe('dev mode', () => {
+    beforeAll(async () => {
+      appPort = await findPort()
+      app = await launchApp(appDir, appPort)
+    })
+    afterAll(() => killApp(app))
+
+    runTests()
+  })
+
+  describe('production mode', () => {
+    beforeAll(async () => {
+      await nextBuild(appDir)
+      appPort = await findPort()
+      app = await nextStart(appDir, appPort)
+    })
+    afterAll(() => killApp(app))
+
+    runTests()
+  })
+})

test/integration/route-indexes/pages/api/sub/[id].js

@@ -0,0 +1 @@
+export default (req, res) => res.end('hi from sub id')

test/integration/route-indexes/pages/api/sub/index.js

@@ -0,0 +1 @@
+export default (req, res) => res.end('hi from sub index')

test/integration/route-indexes/pages/index.js

@@ -0,0 +1,2 @@
+const page = () => 'hello from index'
+export default page

test/integration/route-indexes/pages/nested-index/index/index.js

@@ -0,0 +1 @@
+export default () => 'hello from nested index'

test/integration/route-indexes/pages/sub/[id].js

@@ -0,0 +1,3 @@
+const page = () => 'hello from sub id'
+page.getInitialProps = () => ({ hello: 'hi' })
+export default page

test/integration/route-indexes/pages/sub/index.js

@@ -0,0 +1,3 @@
+const page = () => 'hello from sub index'
+page.getInitialProps = () => ({ hello: 'hi' })
+export default page

test/integration/route-indexes/test/index.test.js

@@ -0,0 +1,138 @@
+/* eslint-env jest */
+/* global jasmine */
+import { join } from 'path'
+import {
+  findPort,
+  launchApp,
+  killApp,
+  nextBuild,
+  nextStart,
+  fetchViaHTTP,
+} from 'next-test-utils'
+
+jasmine.DEFAULT_TIMEOUT_INTERVAL = 1000 * 60 * 2
+
+let app
+let appPort
+const appDir = join(__dirname, '../')
+
+const runTests = () => {
+  it('should handle / correctly', async () => {
+    const res = await fetchViaHTTP(appPort, '/')
+    expect(res.status).toBe(200)
+    expect(await res.text()).toContain('hello from index')
+  })
+
+  it('should handle /index correctly', async () => {
+    const res = await fetchViaHTTP(appPort, '/index')
+    expect(res.status).toBe(200)
+    expect(await res.text()).toContain('hello from index')
+  })
+
+  it('should handle /index/index correctly', async () => {
+    const res = await fetchViaHTTP(appPort, '/index/index')
+    expect(res.status).toBe(404)
+    expect(await res.text()).toContain('page could not be found')
+  })
+
+  it('should handle /nested-index correctly', async () => {
+    const res = await fetchViaHTTP(appPort, '/nested-index')
+    expect(res.status).toBe(404)
+    expect(await res.text()).toContain('page could not be found')
+  })
+
+  it('should handle /nested-index/index correctly', async () => {
+    const res = await fetchViaHTTP(appPort, '/nested-index/index')
+    expect(res.status).toBe(200)
+    expect(await res.text()).toContain('hello from nested index')
+  })
+
+  it('should handle /nested-index/index/index correctly', async () => {
+    const res = await fetchViaHTTP(appPort, '/nested-index/index/index')
+    expect(res.status).toBe(404)
+    expect(await res.text()).toContain('page could not be found')
+  })
+
+  it('should handle /sub correctly', async () => {
+    const res = await fetchViaHTTP(appPort, '/sub')
+    expect(res.status).toBe(200)
+    expect(await res.text()).toContain('hello from sub index')
+  })
+
+  it('should handle /sub/index correctly', async () => {
+    const res = await fetchViaHTTP(appPort, '/sub/index')
+    expect(res.status).toBe(200)
+    expect(await res.text()).toContain('hello from sub id')
+  })
+
+  it('should handle /sub/index/index correctly', async () => {
+    const res = await fetchViaHTTP(appPort, '/sub/index/index')
+    expect(res.status).toBe(404)
+    expect(await res.text()).toContain('page could not be found')
+  })
+
+  it('should handle /sub/another correctly', async () => {
+    const res = await fetchViaHTTP(appPort, '/sub/another')
+    expect(res.status).toBe(200)
+    expect(await res.text()).toContain('hello from sub id')
+  })
+
+  it('should handle /sub/another/index correctly', async () => {
+    const res = await fetchViaHTTP(appPort, '/sub/another/index')
+    expect(res.status).toBe(404)
+    expect(await res.text()).toContain('page could not be found')
+  })
+
+  it('should handle /api/sub correctly', async () => {
+    const res = await fetchViaHTTP(appPort, '/api/sub')
+    expect(res.status).toBe(200)
+    expect(await res.text()).toContain('hi from sub index')
+  })
+
+  it('should handle /api/sub/index correctly', async () => {
+    const res = await fetchViaHTTP(appPort, '/api/sub/index')
+    expect(res.status).toBe(200)
+    expect(await res.text()).toContain('hi from sub id')
+  })
+
+  it('should handle /api/sub/index/index correctly', async () => {
+    const res = await fetchViaHTTP(appPort, '/api/sub/index/index')
+    expect(res.status).toBe(404)
+    expect(await res.text()).toContain('page could not be found')
+  })
+
+  it('should handle /api/sub/another correctly', async () => {
+    const res = await fetchViaHTTP(appPort, '/api/sub/another')
+    expect(res.status).toBe(200)
+    expect(await res.text()).toContain('hi from sub id')
+  })
+
+  it('should handle /api/sub/another/index correctly', async () => {
+    const res = await fetchViaHTTP(appPort, '/api/sub/another/index')
+    expect(res.status).toBe(404)
+    expect(await res.text()).toContain('page could not be found')
+  })
+}
+
+describe('Route indexes handling', () => {
+  describe('dev mode', () => {
+    beforeAll(async () => {
+      appPort = await findPort()
+      app = await launchApp(appDir, appPort)
+    })
+    afterAll(() => killApp(app))
+
+    runTests()
+  })
+
+  describe('production mode', () => {
+    beforeAll(async () => {
+      await nextBuild(appDir)
+      appPort = await findPort()
+      app = await nextStart(appDir, appPort)
+    })
+    afterAll(() => killApp(app))
+
+    runTests()
+  })
+})