Setting `x-stainless-retry-count` to null in defaultHeaders gets ignored

[spaceemotion]

Confirm this is a Node library issue and not an underlying OpenAI API issue

• [X] This is an issue with the Node library

Describe the bug

The recent addition of the x-stainless-retry-count header (https://github.com/openai/openai-node/commit/33e5e9b88f2cdb2ae90e355b394cb8c79f5e22a8) uses the local headers object, which does not include the default headers:

https://github.com/openai/openai-node/blob/785ef4b579637d3a6a205c0a9c51aa71987bf30e/src/core.ts#L391

To Reproduce

1. Create a new OpenAI instance
2. Set the defaultHeaders to include 'x-stainless-retry-count': null
3. See the header being included nonetheless

Code snippets

No response

OS

Windows

Node version

Node v20

Library version

openai 4.67.1

[felladrin]

For readers looking for a workaround while this issue is open:

Setting "x-stainless-retry-count": null individually, in each request, works. For example:

const openai = new OpenAI(/* ...client config... */);

const modelsList = await openai.models.list({
  headers: {
    "x-stainless-retry-count": null,
  },
});

const completion = await openai.chat.completions.create(
  {
    /* ...completion config... */
  },
  {
    headers: {
      "x-stainless-retry-count": null,
    },
  },
);

[RobertCraigie]

Thanks for the report, this should be fixed in v4.68.1!