Bug
res.send() handles Buffer and TypedArray (ArrayBuffer.isView) as binary data, but a raw ArrayBuffer — the standard JavaScript binary data type — falls through to this.json(chunk), producing {}withContent-Type: application/json`.
res.send(new ArrayBuffer(10))
// Sends: {} (Content-Type: application/json)
// Expected: 10 zero bytes (Content-Type: application/octet-stream)Cause
PR #6285 (merged as 55869f4) fixed Uint8Array/DataView support by adding an ArrayBuffer.isView() check. However, ArrayBuffer.isView(new ArrayBuffer(...)) returns false, so raw ArrayBuffer was missed.
Proposed fix
Add an instanceof ArrayBuffer check in lib/response.js that converts to Buffer and sets the binary content type, consistent with the existing ArrayBuffer.isView branch.
Real-world impact
ArrayBuffer is the standard binary type used by fetch, Web Crypto, WebSocket, FileReader, and similar APIs. Passing it directly to res.send() is a common scenario that currently fails silently.
Bug
res.send()handlesBufferand TypedArray (ArrayBuffer.isView) as binary data, but a rawArrayBuffer— the standard JavaScript binary data type — falls through tothis.json(chunk), producing {}withContent-Type: application/json`.Cause
PR #6285 (merged as 55869f4) fixed
Uint8Array/DataViewsupport by adding anArrayBuffer.isView()check. However,ArrayBuffer.isView(new ArrayBuffer(...))returnsfalse, so rawArrayBufferwas missed.Proposed fix
Add an
instanceof ArrayBuffercheck inlib/response.jsthat converts toBufferand sets the binary content type, consistent with the existingArrayBuffer.isViewbranch.Real-world impact
ArrayBufferis the standard binary type used by fetch, Web Crypto, WebSocket, FileReader, and similar APIs. Passing it directly tores.send()is a common scenario that currently fails silently.