refactor: modulurize blobs storage abstractions

Author: pieh

.eslintrc.cjs

@@ -72,6 +72,14 @@ module.exports = {
                 message: 'Please use `getTracer()` from `./handlers/tracer.cjs` instead',
               },
             ],
+            patterns: [
+              {
+                // only */storage/storage.cjs is allowed to be imported
+                // rest are implementation details that should not be used directly
+                group: ['*/storage/*', '!*/storage/storage.cjs'],
+                message: 'Import public `[...]/storage/storage.cjs` module instead.',
+              },
+            ],
           },
         ],
       },

src/run/config.ts

@@ -5,7 +5,7 @@ import { join, resolve } from 'node:path'
 import type { NextConfigComplete } from 'next/dist/server/config-shared.js'
 
 import { PLUGIN_DIR, RUN_CONFIG } from './constants.js'
-import { setInMemoryCacheMaxSizeFromNextConfig } from './regional-blob-store.cjs'
+import { setInMemoryCacheMaxSizeFromNextConfig } from './storage/storage.cjs'
 
 /**
  * Get Next.js config from the build output

src/run/handlers/cache.cts

@@ -25,7 +25,7 @@ import {
 import {
   getMemoizedKeyValueStoreBackedByRegionalBlobStore,
   MemoizedKeyValueStoreBackedByRegionalBlobStore,
-} from '../regional-blob-store.cjs'
+} from '../storage/storage.cjs'
 
 import { getLogger, getRequestContext } from './request-context.cjs'
 import { getTracer, recordWarning } from './tracer.cjs'

src/run/handlers/server.ts

@@ -13,8 +13,8 @@ import {
   setCacheTagsHeaders,
   setVaryHeaders,
 } from '../headers.js'
-import { setFetchBeforeNextPatchedIt } from '../regional-blob-store.cjs'
 import { nextResponseProxy } from '../revalidate.js'
+import { setFetchBeforeNextPatchedIt } from '../storage/storage.cjs'
 
 import { getLogger, type RequestContext } from './request-context.cjs'
 import { getTracer } from './tracer.cjs'

src/run/headers.ts

@@ -5,7 +5,7 @@ import type { NetlifyCachedRouteValue, NetlifyCacheHandlerValue } from '../share
 
 import { getLogger, RequestContext } from './handlers/request-context.cjs'
 import { recordWarning } from './handlers/tracer.cjs'
-import { getMemoizedKeyValueStoreBackedByRegionalBlobStore } from './regional-blob-store.cjs'
+import { getMemoizedKeyValueStoreBackedByRegionalBlobStore } from './storage/storage.cjs'
 
 const ALL_VARIATIONS = Symbol.for('ALL_VARIATIONS')
 interface NetlifyVaryValues {

src/run/next.cts

@@ -8,7 +8,7 @@ import { HtmlBlob } from '../shared/cache-types.cjs'
 
 import { getRequestContext } from './handlers/request-context.cjs'
 import { getTracer } from './handlers/tracer.cjs'
-import { getMemoizedKeyValueStoreBackedByRegionalBlobStore } from './regional-blob-store.cjs'
+import { getMemoizedKeyValueStoreBackedByRegionalBlobStore } from './storage/storage.cjs'
 
 // https://github.com/vercel/next.js/pull/68193/files#diff-37243d614f1f5d3f7ea50bbf2af263f6b1a9a4f70e84427977781e07b02f57f1R49
 // This import resulted in importing unbundled React which depending if NODE_ENV is `production` or not would use

src/run/regional-blob-store.cts

@@ -0,0 +1,62 @@
+import { getDeployStore, GetWithMetadataOptions, Store } from '@netlify/blobs'
+
+const FETCH_BEFORE_NEXT_PATCHED_IT = Symbol.for('nf-not-patched-fetch')
+const extendedGlobalThis = globalThis as typeof globalThis & {
+  [FETCH_BEFORE_NEXT_PATCHED_IT]?: typeof globalThis.fetch
+}
+
+/**
+ * Attempt to extract original fetch in case it was patched by Next.js already
+ *
+ * @see github.com/vercel/next.js/blob/fa214c74c1d8023098c0e94e57f917ef9f1afd1a/packages/next/src/server/lib/patch-fetch.ts#L986
+ */
+function attemptToGetOriginalFetch(
+  fetch: typeof globalThis.fetch & {
+    _nextOriginalFetch?: typeof globalThis.fetch
+  },
+) {
+  return fetch._nextOriginalFetch ?? fetch
+}
+
+function forceOptOutOfUsingDataCache(fetch: typeof globalThis.fetch): typeof globalThis.fetch {
+  return (input, init) => {
+    return fetch(input, {
+      ...init,
+      next: {
+        ...init?.next,
+        // setting next.internal = true should prevent from trying to use data cache
+        // https://github.com/vercel/next.js/blob/fa214c74c1d8023098c0e94e57f917ef9f1afd1a/packages/next/src/server/lib/patch-fetch.ts#L174
+        // https://github.com/vercel/next.js/blob/fa214c74c1d8023098c0e94e57f917ef9f1afd1a/packages/next/src/server/lib/patch-fetch.ts#L210-L213
+        // this is last line of defense in case we didn't manage to get unpatched fetch that will not affect
+        // fetch if it's unpatched so it should be safe to apply always if we aren't sure if we use patched fetch
+
+        // @ts-expect-error - this is an internal field that Next.js doesn't add to its global
+        // type overrides for RequestInit type (like `next.revalidate` or `next.tags`)
+        internal: true,
+      },
+    })
+  }
+}
+
+export const setFetchBeforeNextPatchedIt = (fetch: typeof globalThis.fetch) => {
+  // we store in globalThis in case we have multiple copies of this module
+  // just as precaution
+
+  extendedGlobalThis[FETCH_BEFORE_NEXT_PATCHED_IT] = forceOptOutOfUsingDataCache(
+    attemptToGetOriginalFetch(fetch),
+  )
+}
+
+const fetchBeforeNextPatchedItFallback = forceOptOutOfUsingDataCache(
+  attemptToGetOriginalFetch(globalThis.fetch),
+)
+const getFetchBeforeNextPatchedIt = () =>
+  extendedGlobalThis[FETCH_BEFORE_NEXT_PATCHED_IT] ?? fetchBeforeNextPatchedItFallback
+
+export const getRegionalBlobStore = (args: GetWithMetadataOptions = {}): Store => {
+  return getDeployStore({
+    ...args,
+    fetch: getFetchBeforeNextPatchedIt(),
+    region: process.env.USE_REGIONAL_BLOBS?.toUpperCase() === 'TRUE' ? undefined : 'us-east-2',
+  })
+}