Core: Drop support for IE (all versions)

Author: mgol

.github/workflows/browserstack.yml

@@ -21,7 +21,6 @@ jobs:
       fail-fast: false
       matrix:
         BROWSER:
-          - 'IE_11'
           - 'Safari_latest'
           - 'Safari_latest-1'
           - 'Chrome_latest'

.github/workflows/node.js.yml

@@ -87,34 +87,6 @@ jobs:
       - name: Run tests
         run: npm run ${{ matrix.NPM_SCRIPT }}
 
-  ie:
-    runs-on: windows-latest
-    env:
-      NODE_VERSION: 20.x
-    name: test:ie - IE
-    steps:
-      - name: Checkout
-        uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4.1.7
-
-      - name: Use Node.js ${{ env.NODE_VERSION }}
-        uses: actions/setup-node@1e60f620b9541d16bece96c5465dc8ee9832be0b # v4.0.3
-        with:
-          node-version: ${{ env.NODE_VERSION }}
-
-      - name: Cache
-        uses: actions/cache@0c45773b623bea8c8e75f6c82b208c3cf94ea4f9 # v4.0.2
-        with:
-          path: ~/.npm
-          key: ${{ runner.os }}-node-${{ env.NODE_VERSION }}-npm-lock-${{ hashFiles('**/package-lock.json') }}
-          restore-keys: |
-            ${{ runner.os }}-node-${{ env.NODE_VERSION }}-npm-lock-
-
-      - name: Install dependencies
-        run: npm install
-
-      - name: Run tests in Edge in IE mode
-        run: npm run test:ie
-
   safari:
     runs-on: macos-latest
     env:

build/tasks/npmcopy.js

@@ -11,8 +11,6 @@ const files = {
 	"core-js-bundle/core-js-bundle.js": "core-js-bundle/minified.js",
 	"core-js-bundle/LICENSE": "core-js-bundle/LICENSE",
 
-	"npo/npo.js": "native-promise-only/lib/npo.src.js",
-
 	"qunit/qunit.js": "qunit/qunit/qunit.js",
 	"qunit/qunit.css": "qunit/qunit/qunit.css",
 	"qunit/LICENSE.txt": "qunit/LICENSE.txt",

eslint.config.js

@@ -271,6 +271,15 @@ export default [
 		}
 	},
 
+	{
+		files: [
+			"test/jquery.js"
+		],
+		languageOptions: {
+			ecmaVersion: 2020
+		}
+	},
+
 	{
 		files: [
 			"test/unit/deferred.js"

package-lock.json

@@ -74,7 +74,6 @@
     "test:chrome": "npm run pretest && npm run build:main && npm run test:unit -- -v -b chrome -h",
     "test:edge": "npm run pretest && npm run build:main && npm run test:unit -- -v -b edge -h",
     "test:firefox": "npm run pretest && npm run build:main && npm run test:unit -- -v -b firefox -h",
-    "test:ie": "npm run pretest && npm run build:main && npm run test:unit -- -v -b ie",
     "test:safari": "npm run pretest && npm run build:main && npm run test:unit -- -b safari",
     "test:server": "node test/runner/server.js",
     "test:esm": "npm run pretest && npm run build:main && npm run test:unit -- --esm -h",
@@ -131,7 +130,6 @@
     "jsdom": "24.1.1",
     "marked": "13.0.2",
     "multiparty": "4.2.3",
-    "native-promise-only": "0.8.1",
     "promises-aplus-tests": "2.1.2",
     "q": "1.5.1",
     "qunit": "2.21.1",

package.json

@@ -455,20 +455,12 @@ jQuery.extend( {
 						if ( !responseHeaders ) {
 							responseHeaders = {};
 							while ( ( match = rheaders.exec( responseHeadersString ) ) ) {
-
-								// Support: IE 11+
-								// `getResponseHeader( key )` in IE doesn't combine all header
-								// values for the provided key into a single result with values
-								// joined by commas as other browsers do. Instead, it returns
-								// them on separate lines.
-								responseHeaders[ match[ 1 ].toLowerCase() + " " ] =
-									( responseHeaders[ match[ 1 ].toLowerCase() + " " ] || [] )
-										.concat( match[ 2 ] );
+								responseHeaders[ match[ 1 ].toLowerCase() + " " ] = match[ 2 ];
 							}
 						}
 						match = responseHeaders[ key.toLowerCase() + " " ];
 					}
-					return match == null ? null : match.join( ", " );
+					return match == null ? null : match;
 				},
 
 				// Raw string
@@ -542,24 +534,8 @@ jQuery.extend( {
 		// A cross-domain request is in order when the origin doesn't match the current origin.
 		if ( s.crossDomain == null ) {
 			urlAnchor = document.createElement( "a" );
-
-			// Support: IE <=8 - 11+
-			// IE throws exception on accessing the href property if url is malformed,
-			// e.g. http://example.com:80x/
-			try {
-				urlAnchor.href = s.url;
-
-				// Support: IE <=8 - 11+
-				// Anchor's host property isn't correctly set when s.url is relative
-				urlAnchor.href = urlAnchor.href;
-				s.crossDomain = originAnchor.protocol + "//" + originAnchor.host !==
-					urlAnchor.protocol + "//" + urlAnchor.host;
-			} catch ( e ) {
-
-				// If there is an error parsing the URL, assume it is crossDomain,
-				// it can be rejected by the transport if it is invalid
-				s.crossDomain = true;
-			}
+			urlAnchor.href = s.url;
+			s.crossDomain = originAnchor.origin !== urlAnchor.origin;
 		}
 
 		// Apply prefilters

src/ajax.js

@@ -50,8 +50,8 @@ jQuery.fn.load = function( url, params, callback ) {
 
 			self.html( selector ?
 
-				// If a selector was specified, locate the right elements in a dummy div
-				// Exclude scripts to avoid IE 'Permission Denied' errors
+				// If a selector was specified, locate the right elements in a dummy div.
+				// Exclude scripts.
 				jQuery( "<div>" ).append( jQuery.parseHTML( responseText ) ).find( selector ) :
 
 				// Otherwise use the full result

src/ajax/load.js

@@ -1,8 +1,6 @@
 import { jQuery } from "../core.js";
 import { access } from "../core/access.js";
-import { nodeName } from "../core/nodeName.js";
 import { rnothtmlwhite } from "../var/rnothtmlwhite.js";
-import { isIE } from "../var/isIE.js";
 
 jQuery.fn.extend( {
 	attr: function( name, value ) {
@@ -86,20 +84,3 @@ jQuery.extend( {
 		}
 	}
 } );
-
-// Support: IE <=11+
-// An input loses its value after becoming a radio
-if ( isIE ) {
-	jQuery.attrHooks.type = {
-		set: function( elem, value ) {
-			if ( value === "radio" && nodeName( elem, "input" ) ) {
-				var val = elem.value;
-				elem.setAttribute( "type", value );
-				if ( val ) {
-					elem.value = val;
-				}
-				return value;
-			}
-		}
-	};
-}

src/attributes/attr.js

@@ -1,6 +1,5 @@
 import { jQuery } from "../core.js";
 import { access } from "../core/access.js";
-import { isIE } from "../var/isIE.js";
 
 var rfocusable = /^(?:input|select|textarea|button)$/i,
 	rclickable = /^(?:a|area)$/i;
@@ -54,7 +53,6 @@ jQuery.extend( {
 		tabIndex: {
 			get: function( elem ) {
 
-				// Support: IE <=9 - 11+
 				// elem.tabIndex doesn't always return the
 				// correct value when it hasn't been explicitly set
 				// Use proper attribute retrieval (trac-12072)
@@ -85,39 +83,6 @@ jQuery.extend( {
 	}
 } );
 
-// Support: IE <=11+
-// Accessing the selectedIndex property forces the browser to respect
-// setting selected on the option. The getter ensures a default option
-// is selected when in an optgroup. ESLint rule "no-unused-expressions"
-// is disabled for this code since it considers such accessions noop.
-if ( isIE ) {
-	jQuery.propHooks.selected = {
-		get: function( elem ) {
-
-			var parent = elem.parentNode;
-			if ( parent && parent.parentNode ) {
-				// eslint-disable-next-line no-unused-expressions
-				parent.parentNode.selectedIndex;
-			}
-			return null;
-		},
-		set: function( elem ) {
-
-
-			var parent = elem.parentNode;
-			if ( parent ) {
-				// eslint-disable-next-line no-unused-expressions
-				parent.selectedIndex;
-
-				if ( parent.parentNode ) {
-					// eslint-disable-next-line no-unused-expressions
-					parent.parentNode.selectedIndex;
-				}
-			}
-		}
-	};
-}
-
 jQuery.each( [
 	"tabIndex",
 	"readOnly",