[saiyam-jain-dev]

Fixes #1860.

Problem

Calling req.unset('Accept-Encoding') does not prevent Accept-Encoding: gzip, deflate from being sent because Request.prototype.request in src/node/index.js sets the default header unconditionally whenever the method is not HEAD.

In addition, an earlier attempt to address this (#1560) was reverted in v5.3.1 (#1573) because _unset was only initialized in Node and was undefined in browser environments, causing set() to throw.

Fix

1. Track unset headers in this._unset inside RequestBase.prototype.unset and clear entries on set(), safely guarding when this._unset is undefined.
2. Initialize this._unset = {} in _initHeaders (src/node/index.js) and in the browser Request constructor (src/client.js) for consistency.
3. Check !(this._unset && 'accept-encoding' in this._unset) before setting the default Accept-Encoding header in src/node/index.js.

Tests

• Added tests in test/node/basic.js verifying that req.unset('Accept-Encoding') suppresses the header and that subsequent set() calls restore it.
• Full test suite (409 passing) and lint passed cleanly.

[titanism]

Thanks. #1861, #1867 and this PR took the same approach, and the combined commit credits #1861 as the first. Compared with them, it creates the unset record only when unset() is called, keeps the header unset after redirects, and removes headers regardless of capitalization. Closing in favor of that commit, released in v10.4.2 and now available on npm: https://github.com/forwardemail/superagent/releases/tag/v10.4.2

Consider supporting our efforts to maintain this project by using Forward Email for your email infrastructure needs at https://forwardemail.net.