Build: Update jQuery to 4.0.0-rc.1, update README

Closes gh-581

Author: mgol

README.md

@@ -1,6 +1,6 @@
 ![CI Status](https://github.com/jquery/jquery-migrate/actions/workflows/node.js.yml/badge.svg?branch=main)
 
-#### NOTE: To upgrade to jQuery 3.0, you first need version 1.12.x or 2.2.x. If you're using an older version, first upgrade to one of these versions using [jQuery Migrate 1.x](https://github.com/jquery/jquery-migrate/tree/1.x-stable#readme), to resolve any compatibility issues. For more information about the changes made in jQuery 3.0, see the [upgrade guide](https://jquery.com/upgrade-guide/3.0/) and [blog post](https://blog.jquery.com/2016/06/09/jquery-3-0-final-released/).
+#### NOTE: To upgrade to jQuery 4.x, you first need version 3.x. If you're using an older version, first upgrade to jQuery 3.x using [jQuery Migrate 3.x](https://github.com/jquery/jquery-migrate/tree/3.x-stable#readme), to resolve any compatibility issues. For more information about the changes made in jQuery 4.0, see the [upgrade guide](https://jquery.com/upgrade-guide/4.0/) and [blog post](https://blog.jquery.com/2025/08/11/jquery-4-0-0-release-candidate-1/).
 
 # jQuery Migrate
 Upgrading libraries such as jQuery can be a lot of work, when breaking changes have been introduced. jQuery Migrate makes this easier, by restoring the APIs that were removed, and additionally shows warnings in the browser console (development version of jQuery Migrate only) when removed and/or deprecated APIs are used.
@@ -25,8 +25,8 @@ Each jQuery Migrate version supports the same browsers that the jQuery version u
 In your web page, load this plugin *after* the script tag for jQuery, for example:
 
 ```html
-<script src="https://code.jquery.com/jquery-3.7.1.js"></script>
-<script src="https://code.jquery.com/jquery-migrate-3.5.2.js"></script>
+<script src="https://code.jquery.com/jquery-4.0.0-rc.1.js"></script>
+<script src="https://code.jquery.com/jquery-migrate-4.0.0-beta.1.js"></script>
 ```
 
 ## Download

jtr-ci.yml

@@ -6,8 +6,8 @@ runs:
     - git.min
     - git.slim
     - git.slim.min
-    - 4.0.0-beta.2
-    - 4.0.0-beta.2.slim
+    - 4.0.0-rc.1
+    - 4.0.0-rc.1.slim
   plugin:
     - dev
     - min

jtr-local.yml

@@ -6,7 +6,7 @@ runs:
     - git.min
     - git.slim
     - git.slim.min
-    - 4.0.0-beta.2
-    - 4.0.0-beta.2.slim
+    - 4.0.0-rc.1
+    - 4.0.0-rc.1.slim
 
 retries: 1

package-lock.json

@@ -65,7 +65,7 @@
 		"eslint-plugin-import": "2.31.0",
 		"globals": "15.15.0",
 		"husky": "9.1.7",
-		"jquery": "4.0.0-beta.2",
+		"jquery": "4.0.0-rc.1",
 		"jquery-test-runner": "0.2.5",
 		"jsdom": "26.0.0",
 		"native-promise-only": "0.8.1",

package.json

@@ -8,7 +8,7 @@
 	 *	dev			Uncompressed development version: source files in the project /dist dir
 	 *	esmodules	Non-combined dev version: source files from the project /src dir
 	 *	min			Minified version in the project /dist dir
-	 *	VER			Version from code.jquery.com, e.g.: git, 4.0.0.min or 4.0.0-beta.2
+	 *	VER			Version from code.jquery.com, e.g.: git, 4.0.0.min or 4.0.0-rc.1
 	 *	else		Full or relative path to be used for script src
 	 */
 	loadProject: function( projectName, defaultVersion, isSelf ) {
@@ -244,8 +244,8 @@ TestManager.init( {
 			"git.min",
 			"git.slim",
 			"git.slim.min",
-			"4.0.0-beta.2",
-			"4.0.0-beta.2.slim"
+			"4.0.0-rc.1",
+			"4.0.0-rc.1.slim"
 		]
 	},
 	"jquery-migrate": {