fix: fix patching the fs by doing a shallow clone of fs/promises module to avoid infinite loop (#73)

Author: lukasholzer

src/run/handlers/next.cts

@@ -1,5 +1,5 @@
-import * as fs from 'fs/promises'
 import { join, relative } from 'path'
+import fs from 'fs/promises'
 
 import type { getRequestHandlers } from 'next/dist/server/lib/start-server.js'
 
@@ -10,13 +10,14 @@ type FS = typeof import('fs')
 
 export async function getMockedRequestHandlers(...args: Parameters<typeof getRequestHandlers>) {
   const { blobStore } = await import('./cache.cjs')
+  const ofs = { ...fs }
 
   async function readFileFallbackBlobStore(...args: Parameters<FS['promises']['readFile']>) {
     const [path, options] = args
     try {
       // Attempt to read from the disk
       // important to use the `import * as fs from 'fs'` here to not end up in a endless loop
-      return await fs.readFile(path, options)
+      return await ofs.readFile(path, options)
     } catch (error) {
       // only try to get .html files from the blob store
       if (typeof path === 'string' && path.endsWith('.html')) {

src/run/handlers/server.ts

@@ -14,9 +14,9 @@ export default async (request: Request) => {
     nextConfig = await getRunConfig()
     setRunConfig(nextConfig)
 
-    const { getRequestHandlers } = await import('next/dist/server/lib/start-server.js')
+    const { getMockedRequestHandlers } = await import('./next.cjs')
 
-    ;[nextHandler] = await getRequestHandlers({
+    ;[nextHandler] = await getMockedRequestHandlers({
       port: 3000,
       hostname: 'localhost',
       dir: RUN_DIR,

src/run/headers.ts

@@ -7,7 +7,7 @@ interface NetlifyVaryValues {
 }
 
 const generateNetlifyVaryValues = ({ headers, languages, cookies }: NetlifyVaryValues): string => {
-  const values = []
+  const values: string[] = []
   if (headers.length !== 0) {
     values.push(`header=${headers.join(`|`)}`)
   }

tests/integration/static.test.ts

@@ -24,7 +24,7 @@ beforeEach<FixtureTestContext>(async (ctx) => {
   await startMockBlobStore(ctx)
 })
 
-test.skip<FixtureTestContext>('requesting a non existing page route that needs to be fetched from the CDN', async (ctx) => {
+test<FixtureTestContext>('requesting a non existing page route that needs to be fetched from the CDN', async (ctx) => {
   await createFixture('page-router', ctx)
   await runPlugin(ctx)