fix(blob): limit keys to 950 characters

.changeset/unlucky-months-repeat.md

@@ -0,0 +1,5 @@
+---
+'@vercel/blob': patch
+---
+
+Limit pathname length to 950 to respect internal limitations and provide better early DX.

packages/blob/src/api.ts

@@ -5,6 +5,12 @@ import { debug } from './debug';
 import type { BlobCommandOptions } from './helpers';
 import { BlobError, getTokenFromOptionsOrEnv } from './helpers';
 
+// maximum pathname length is:
+// 1024 (provider limit) - 26 chars (vercel  internal suffixes) - 31 chars (blob `-randomId` suffix) = 967
+// we round it to 950 to make it more human friendly, and we apply the limit whatever the value of
+// addRandomSuffix is, to make it consistent
+export const MAXIMUM_PATHNAME_LENGTH = 950;
+
 export class BlobAccessError extends BlobError {
   constructor() {
     super('Access denied, please provide a valid token for this resource.');

packages/blob/src/copy.ts

@@ -1,4 +1,4 @@
-import { requestApi } from './api';
+import { MAXIMUM_PATHNAME_LENGTH, requestApi } from './api';
 import type { CommonCreateBlobOptions } from './helpers';
 import { BlobError } from './helpers';
 
@@ -35,6 +35,12 @@ export async function copy(
     throw new BlobError('access must be "public"');
   }
 
+  if (toPathname.length > MAXIMUM_PATHNAME_LENGTH) {
+    throw new BlobError(
+      `pathname is too long, maximum length is ${MAXIMUM_PATHNAME_LENGTH}`,
+    );
+  }
+
   const headers: Record<string, string> = {};
 
   if (options.addRandomSuffix !== undefined) {

packages/blob/src/index.node.test.ts

@@ -576,6 +576,16 @@ describe('blob client', () => {
       expect(headers['x-cache-control-max-age']).toEqual('60');
     });
 
+    it('throws when filepath is too long', async () => {
+      await expect(
+        put('a'.repeat(951), 'Test Body', {
+          access: 'public',
+        }),
+      ).rejects.toThrow(
+        new Error('Vercel Blob: pathname is too long, maximum length is 950'),
+      );
+    });
+
     const table: [string, (signal: AbortSignal) => Promise<unknown>][] = [
       [
         'put',
@@ -701,4 +711,16 @@ describe('blob client', () => {
       );
     });
   });
+
+  describe('copy', () => {
+    it('throws when filepath is too long', async () => {
+      await expect(
+        copy('source', 'a'.repeat(951), {
+          access: 'public',
+        }),
+      ).rejects.toThrow(
+        new Error('Vercel Blob: pathname is too long, maximum length is 950'),
+      );
+    });
+  });
 });

packages/blob/src/put-helpers.ts

@@ -3,6 +3,7 @@ import type { Readable } from 'stream';
 import type { ClientCommonCreateBlobOptions } from './client';
 import type { CommonCreateBlobOptions } from './helpers';
 import { BlobError } from './helpers';
+import { MAXIMUM_PATHNAME_LENGTH } from './api';
 
 const putOptionHeaderMap = {
   cacheControlMaxAge: 'x-cache-control-max-age',
@@ -85,6 +86,12 @@ export async function createPutOptions<
     throw new BlobError('pathname is required');
   }
 
+  if (pathname.length > MAXIMUM_PATHNAME_LENGTH) {
+    throw new BlobError(
+      `pathname is too long, maximum length is ${MAXIMUM_PATHNAME_LENGTH}`,
+    );
+  }
+
   if (!options) {
     throw new BlobError('missing options, see usage');
   }