TypeError: res.body.getReader is not a function - Response Body Handling Issue

[MapDev76]

Description

I encountered an issue with the @hono/node-server library when attempting to access the getReader method on res.body. The method is not available, resulting in the following error:
TypeError: res.body.getReader is not a function at responseViaResponseObject (file:///home/pinna-marco-antonio/lili/back/node_modules/@hono/node-server/dist/index.mjs:420:29) at process.processTicksAndRejections (node:internal/process/task_queues:105:5) at async Server. (file:///home/pinna-marco-antonio/lili/back/node_modules/@hono/node-server/dist/index.mjs:551:14)

Code

Steps to Reproduce

1. Environment:
   • Node.js version: [Your Node.js version here, e.g. 18.17.0]
   • @hono/node-server version: [Library version here, e.g. 2.3.0]
   • Operating System: [Your OS, e.g. Ubuntu 22.04 or Windows 11]
2. Code example:

   console.log(res.body.getReader());

3. A response from the server that includes an empty body triggers the issue.

Expected Behavior

The library should handle the res.body safely, ensuring that the response body can be processed without errors, even if it is empty or not a ReadableStream.

Current Behavior

The res.body object does not have a getReader method, which causes the application to throw a TypeError.

Possible Solution

To fix this issue, the res.body should be checked for the presence of the getReader method before calling it. Here's an example solution:

if (res.body && typeof res.body.getReader === 'function') {
    const reader = res.body.getReader();
    // Handle response stream here
} else {
    console.warn('res.body does not support getReader');
}
For standard Node.js streams, an alternative approach could be used to read the response body safely.

Additional Notes
The issue was discovered in the following context:
An incoming HTTP request triggers a 204 No Content response, which does not have a body.
The library throws a TypeError when attempting to process this response.
Please let me know if you need further details, or if I can provide a minimal reproduction repository for debugging.

[Tilakmahajan]

Hi 👋

This is happening because res.body in Node.js is not always a Web ReadableStream.

The getReader() method exists only on the Web Streams API ReadableStream (browser/Fetch standard). In the Node runtime, the response body can be:

• null (e.g. 204 No Content)
• a Node.js stream
• or another implementation that does not expose getReader()

So calling:

res.body.getReader()

will throw:

TypeError: res.body.getReader is not a function

If you are running on Node, you should either:

1. Check if res.body exists and supports getReader:

   if (res.body && typeof (res.body as any).getReader === 'function') {
   const reader = (res.body as ReadableStream).getReader()
   }

2. Or use standard response helpers like:

   await res.text()
   await res.json()
   await res.arrayBuffer()

If you're expecting streaming behavior, make sure you're working with a Web-compatible runtime (e.g. edge / fetch API environment) instead of the Node adapter.

Also note that a 204 response does not have a body, so res.body will be null.

This is expected behavior rather than a Hono bug 👍