fix: internal vs external metadata headers (#92)

Co-authored-by: Eduardo Bouças <mail@eduardoboucas.com>

Author: cbosss

src/client.ts

@@ -59,7 +59,7 @@ export class Client {
       }
 
       if (encodedMetadata) {
-        headers[METADATA_HEADER_EXTERNAL] = encodedMetadata
+        headers[METADATA_HEADER_INTERNAL] = encodedMetadata
       }
 
       const path = key ? `/${this.siteID}/${storeName}/${key}` : `/${this.siteID}/${storeName}`

src/main.test.ts

@@ -1007,7 +1007,7 @@ describe('setJSON', () => {
         headers: {
           authorization: `Bearer ${edgeToken}`,
           'cache-control': 'max-age=0, stale-while-revalidate=60',
-          'netlify-blobs-metadata': encodedMetadata,
+          'x-amz-meta-user': encodedMetadata,
         },
         response: new Response(null),
         url: `${edgeURL}/${siteID}/production/${key}`,

src/metadata.ts

@@ -39,8 +39,12 @@ export const getMetadataFromResponse = (response: Response) => {
     return {}
   }
 
+  // If metadata is coming from the API, it will be under the external header.
+  // If it's coming from the edge, it will be under the internal header.
+  const value = response.headers.get(METADATA_HEADER_EXTERNAL) || response.headers.get(METADATA_HEADER_INTERNAL)
+
   try {
-    return decodeMetadata(response.headers.get(METADATA_HEADER_INTERNAL))
+    return decodeMetadata(value)
   } catch {
     throw new Error(
       'An internal error occurred while trying to retrieve the metadata for an entry. Please try updating to the latest version of the Netlify Blobs client.',

src/server.ts

@@ -4,7 +4,7 @@ import { tmpdir } from 'node:os'
 import { dirname, join, relative, resolve, sep } from 'node:path'
 
 import { ListResponse } from './backend/list.ts'
-import { decodeMetadata, encodeMetadata, METADATA_HEADER_EXTERNAL, METADATA_HEADER_INTERNAL } from './metadata.ts'
+import { decodeMetadata, encodeMetadata, METADATA_HEADER_INTERNAL } from './metadata.ts'
 import { isNodeError, Logger } from './util.ts'
 
 interface BlobsServerOptions {
@@ -163,7 +163,7 @@ export class BlobsServer {
       return this.sendResponse(req, res, 400)
     }
 
-    const metadataHeader = req.headers[METADATA_HEADER_EXTERNAL]
+    const metadataHeader = req.headers[METADATA_HEADER_INTERNAL]
     const metadata = decodeMetadata(Array.isArray(metadataHeader) ? metadataHeader[0] : metadataHeader ?? null)
 
     try {