fix: Remove the default connection close header (#1765)

dhedey · web-flow · commit 65ae25a1da28 · 2023-08-18T22:23:31.000+02:00
Instead, we rely on the underlying http implementation in Node.js to handle this, as per the documentation at https://nodejs.org/api/http.html#new-agentoptions This fixes #1735 and likely replaces #1473 The original change introducing this provided no clear motivation for the override, and the implementation has since been changed to disable this header when an agent is provided, so I think there is sufficient evidence that removing this is the correct behaviour. af21ae6 7f68577 This commit is backported to the v2 branch from #1736 against v3.
diff --git a/README.md b/README.md
@@ -387,7 +387,6 @@ Header              | Value
 ------------------- | --------------------------------------------------------
 `Accept-Encoding`   | `gzip,deflate` _(when `options.compress === true`)_
 `Accept`            | `*/*`
-`Connection`        | `close` _(when no `options.agent` is present)_
 `Content-Length`    | _(automatically calculated, if possible)_
 `Transfer-Encoding` | `chunked` _(when `req.body` is a stream)_
 `User-Agent`        | `node-fetch/1.0 (+https://github.com/bitinn/node-fetch)`
@@ -404,6 +403,8 @@ The `agent` option allows you to specify networking related options which are ou
 
 See [`http.Agent`](https://nodejs.org/api/http.html#http_new_agent_options) for more information.
 
+If no agent is specified, the default agent provided by Node.js is used. Note that [this changed in Node.js 19](https://github.com/nodejs/node/blob/4267b92604ad78584244488e7f7508a690cb80d0/lib/_http_agent.js#L564) to have `keepalive` true by default. If you wish to enable `keepalive` in an earlier version of Node.js, you can override the agent as per the following code sample. 
+
 In addition, the `agent` option accepts a function that returns `http`(s)`.Agent` instance given current [URL](https://nodejs.org/api/url.html), this is useful during a redirection chain across HTTP and HTTPS protocol.
 
 ```js
diff --git a/src/request.js b/src/request.js
@@ -258,10 +258,6 @@ export function getNodeRequestOptions(request) {
 		agent = agent(parsedURL);
 	}
 
-	if (!headers.has('Connection') && !agent) {
-		headers.set('Connection', 'close');
-	}
-
 	// HTTP-network fetch step 4.2
 	// chunked encoding is handled by Node.js
 

Original file line number	Diff line number	Diff line change
`@@ -258,10 +258,6 @@ export function getNodeRequestOptions(request) {`
`258`	`258`	`agent = agent(parsedURL);`
`259`	`259`	`}`
`260`	`260`
`261`		`- if (!headers.has('Connection') && !agent) {`
`262`		`- headers.set('Connection', 'close');`
`263`		`- }`
`264`		`-`
`265`	`261`	`// HTTP-network fetch step 4.2`
`266`	`262`	`// chunked encoding is handled by Node.js`
`267`	`263`