http: decode username and password before encoding

doc/api/url.md

@@ -470,6 +470,12 @@ the URL, use the [`url.search`][] setter. See [`URLSearchParams`][]
 documentation for details.
 
 #### `url.username`
+<!-- YAML
+changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/31450
+    description: When used with `http.request()`, this field will now be
+                 percent-decoded.
 
 * {string}
 
@@ -488,7 +494,8 @@ console.log(myURL.href);
 Any invalid URL characters appearing in the value assigned the `username`
 property will be [percent-encoded][]. The selection of which
 characters to percent-encode may vary somewhat from what the [`url.parse()`][]
-and [`url.format()`][] methods would produce.
+and [`url.format()`][] methods would produce. When used with
+[`http.request()`][], this field will be percent-decoded.
 
 #### `url.toString()`
 
@@ -1316,6 +1323,7 @@ console.log(myURL.origin);
 [`TypeError`]: errors.html#errors_class_typeerror
 [`URLSearchParams`]: #url_class_urlsearchparams
 [`array.toString()`]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/toString
+[`http.request()`]: http.html#http_http_request_options_callback
 [`new URL()`]: #url_constructor_new_url_input_base
 [`querystring`]: querystring.html
 [`require('url').format()`]: #url_url_format_url_options

lib/internal/url.js

@@ -1284,7 +1284,8 @@ function urlToOptions(url) {
     options.port = Number(url.port);
   }
   if (url.username || url.password) {
-    options.auth = `${url.username}:${url.password}`;
+    options.auth =
+      `${decodeURIComponent(url.username)}:${decodeURIComponent(url.password)}`;
   }
   return options;
 }

test/parallel/test-http-url-username.js

@@ -0,0 +1,33 @@
+'use strict';
+const common = require('../common');
+const assert = require('assert');
+const http = require('http');
+const MakeDuplexPair = require('../common/duplexpair');
+
+// Test that usernames from URLs are URL-decoded, as they should be.
+
+{
+  const url = new URL('http://localhost');
+  url.username = 'test@test';
+  url.password = '123456';
+
+  const server = http.createServer(
+    common.mustCall((req, res) => {
+      assert.strictEqual(
+        req.headers.authorization,
+        'Basic ' + Buffer.from('test@test:123456').toString('base64'));
+      res.statusCode = 200;
+      res.end();
+    }));
+
+  const { clientSide, serverSide } = MakeDuplexPair();
+  server.emit('connection', serverSide);
+
+  const req = http.request(url, {
+    createConnection: common.mustCall(() => clientSide)
+  }, common.mustCall((res) => {
+    res.resume();  // We don’t actually care about contents.
+    res.on('end', common.mustCall());
+  }));
+  req.end();
+}