From 9b9ed469b43e9fa6e2c752444470ae4c87d03d57 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micha=C5=82=20Go=C5=82=C4=99biowski-Owczarek?=
 <m.goleb@gmail.com>
Date: Tue, 7 Jan 2020 16:42:49 +0100
Subject: [PATCH] Build: Create a `grunt custom:slim` alias for the Slim build
 (#4578)

Closes gh-4578
---
 README.md            |  5 +++++
 build/release.js     |  2 +-
 build/tasks/build.js | 20 +++++++++++++++++++-
 3 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/README.md b/README.md
index 104f3ecca..9302b2f14 100644
--- a/README.md
+++ b/README.md
@@ -146,6 +146,11 @@ Exclude a bunch of modules:
 grunt custom:-ajax,-css,-deprecated,-dimensions,-effects,-event/alias,-offset,-wrap
 ```
 
+There is also a special alias to generate a build with the same configuration as the official jQuery Slim build is generated:
+```bash
+grunt custom:slim
+```
+
 For questions or requests regarding custom builds, please start a thread on the [Developing jQuery Core](https://forum.jquery.com/developing-jquery-core) section of the forum. Due to the combinatorics and custom nature of these builds, they are not regularly tested in jQuery's unit test process.
 
 Running the Unit Tests
diff --git a/build/release.js b/build/release.js
index f463d8e40..e0116d160 100644
--- a/build/release.js
+++ b/build/release.js
@@ -50,7 +50,7 @@ module.exports = function( Release ) {
 		generateArtifacts: function( callback ) {
 			Release.exec( "grunt", "Grunt command failed" );
 			Release.exec(
-				"grunt custom:-ajax,-effects --filename=jquery.slim.js && " +
+				"grunt custom:slim --filename=jquery.slim.js && " +
 					"grunt remove_map_comment --filename=jquery.slim.js",
 				"Grunt custom failed"
 			);
diff --git a/build/tasks/build.js b/build/tasks/build.js
index 4abc70868..18d101f0b 100644
--- a/build/tasks/build.js
+++ b/build/tasks/build.js
@@ -291,9 +291,27 @@ module.exports = function( grunt ) {
 	// Becomes:
 	//
 	//   grunt build:*:*:+ajax:-dimensions:-effects:-offset
+	//
+	// There's also a special "slim" alias that resolves to the jQuery Slim build
+	// configuration:
+	//
+	//   grunt custom:slim
 	grunt.registerTask( "custom", function() {
 		const args = this.args;
-		const modules = args.length ? args[ 0 ].replace( /,/g, ":" ) : "";
+		const modules = args.length ?
+			args[ 0 ]
+				.split( "," )
+
+				// Replace "slim" with respective exclusions meant for
+				// the official slim build
+				.reduce( ( acc, elem ) => acc.concat(
+					elem === "slim" ?
+						[ "-ajax", "-effects" ] :
+						[ elem ]
+				), [] )
+
+				.join( ":" ) :
+			"";
 		const done = this.async();
 		const insight = new Insight( {
 			trackingCode: "UA-1076265-4",