test(upload-client): allow large byte uploads

There was an issue with large byte uploads in tests.

This commit fixes the issue by first converting bytes to UnixFS stream before making CAR object in packages/upload-client/test/helpers/car.js

packages/upload-client/test/helpers/car.js

@@ -1,23 +1,26 @@
 import { CarWriter } from '@ipld/car'
 import * as CAR from '@ucanto/transport/car'
-import { toBlock } from './block.js'
+import { createFileEncoderStream } from '../../src/unixfs.js'
 
 /**
  * @param {Uint8Array} bytes
  */
 export async function toCAR(bytes) {
-  const block = await toBlock(bytes)
-  // @ts-expect-error old multiformats in @ipld/car
-  const { writer, out } = CarWriter.create(block.cid)
-  writer.put(block)
+  const readableStream = ((createFileEncoderStream(new Blob([bytes]), {})))
+
+  let blocks = [], chunks = []
+  // @ts-expect-error readable Stream is also an async iterable
+  for await (let block of readableStream) blocks.push(block)
+  const rootCID = blocks.at(-1)?.cid
+
+  const { writer, out } = CarWriter.create(rootCID)
+
+  for (const block of blocks) writer.put(block)
   writer.close()
 
-  const chunks = []
-  for await (const chunk of out) {
-    chunks.push(chunk)
-  }
+  for await (const chunk of out) chunks.push(chunk)
+
   const blob = new Blob(chunks)
   const cid = await CAR.codec.link(new Uint8Array(await blob.arrayBuffer()))
-
-  return Object.assign(blob, { cid, roots: [block.cid] })
+  return  Object.assign(blob, { cid, roots: [rootCID] })
 }