Build: Rename master to main across the repository

The default branch was updated, this updates the remaining occurrences in code
& comments.

Closes gh-4838

CONTRIBUTING.md

@@ -85,16 +85,16 @@ Change directory to the newly created dir jquery/
 $ cd jquery
 ```
 
-Add the jQuery master as a remote. I label mine "upstream"
+Add the jQuery main as a remote. I label mine "upstream"
 
 ```bash
 $ git remote add upstream git://github.com/jquery/jquery.git
 ```
 
-Get in the habit of pulling in the "upstream" master to stay up to date as jQuery receives new commits
+Get in the habit of pulling in the "upstream" main to stay up to date as jQuery receives new commits
 
 ```bash
-$ git pull upstream master
+$ git pull upstream main
 ```
 
 Run the build script

README.md

@@ -216,7 +216,7 @@ As the source code is handled by the Git version control system, it's useful to
 If you want to purge your working directory back to the status of upstream, the following commands can be used (remember everything you've worked on is gone after these):
 
 ```bash
-git reset --hard upstream/master
+git reset --hard upstream/main
 git clean -fdx
 ```
 
@@ -274,7 +274,7 @@ throws( block, [expected], [message] );
 ```
 
 
-Test Suite Convenience Methods Reference (See [test/data/testinit.js](https://github.com/jquery/jquery/blob/master/test/data/testinit.js))
+Test Suite Convenience Methods Reference (See [test/data/testinit.js](https://github.com/jquery/jquery/blob/main/test/data/testinit.js))
 ------------------------------
 
 ### Returns an array of elements with the given IDs ###

build/release/dist.js

@@ -31,9 +31,9 @@ module.exports = function( Release, files, complete ) {
 		Release.exec( `git clone ${ distRemote } ${ Release.dir.dist }`,
 			"Error cloning repo." );
 
-		// Distribution always works on master
+		// Distribution always works on main
 		Release.chdir( Release.dir.dist );
-		Release.exec( "git checkout master", "Error checking out branch." );
+		Release.exec( "git checkout main", "Error checking out branch." );
 		console.log();
 	}
 
@@ -140,8 +140,8 @@ module.exports = function( Release, files, complete ) {
 		Release.exec(
 			`git push ${
 				Release.isTest ? " --dry-run" : ""
-			} ${ distRemote } master --tags`,
-			"Error pushing master and tags to git repo."
+			} ${ distRemote } main --tags`,
+			"Error pushing main and tags to git repo."
 		);
 
 		// Set repo for npm publish

package.json

@@ -7,7 +7,7 @@
   "homepage": "https://jquery.com",
   "author": {
     "name": "OpenJS Foundation and other contributors",
-    "url": "https://github.com/jquery/jquery/blob/master/AUTHORS.txt"
+    "url": "https://github.com/jquery/jquery/blob/main/AUTHORS.txt"
   },
   "repository": {
     "type": "git",

test/unit/offset.js

@@ -63,7 +63,7 @@ QUnit.test( "disconnected element", function( assert ) {
 
 	var result = jQuery( document.createElement( "div" ) ).offset();
 
-	// These tests are solely for master/compat consistency
+	// These tests are solely for main/compat consistency
 	// Retrieving offset on disconnected/hidden elements is not officially
 	// valid input, but will return zeros for back-compat
 	assert.equal( result.top, 0, "Retrieving offset on disconnected elements returns zeros (gh-2310)" );
@@ -80,7 +80,7 @@ QUnit.test( "hidden (display: none) element", function( assert ) {
 
 	node.remove();
 
-	// These tests are solely for master/compat consistency
+	// These tests are solely for main/compat consistency
 	// Retrieving offset on disconnected/hidden elements is not officially
 	// valid input, but will return zeros for back-compat
 	assert.equal( result.top, 0, "Retrieving offset on hidden elements returns zeros (gh-2310)" );
@@ -454,7 +454,7 @@ testIframe( "scroll", "offset/scroll.html", function( assert, $, win ) {
 	assert.equal( $( "#scroll-1-1" ).offset().top, 11, "jQuery('#scroll-1-1').offset().top" );
 	assert.equal( $( "#scroll-1-1" ).offset().left, 11, "jQuery('#scroll-1-1').offset().left" );
 
-	// These tests are solely for master/compat consistency
+	// These tests are solely for main/compat consistency
 	// Retrieving offset on disconnected/hidden elements is not officially
 	// valid input, but will return zeros for back-compat
 	assert.equal( $( "#hidden" ).offset().top, 0, "Hidden elements do not subtract scroll" );