🚮 Remove IE Support via Polyfills and Conditional Statements

build-system/test-configs/dep-check-config.js

@@ -424,7 +424,6 @@ exports.rules = [
       '3p/polyfills.js->src/polyfills/string-starts-with.js',
       'src/amp.js->src/polyfills/index.js',
       'src/polyfills/index.js->src/polyfills/abort-controller.js',
-      'src/polyfills/index.js->src/polyfills/domtokenlist.js',
       'src/polyfills/index.js->src/polyfills/document-contains.js',
       'src/polyfills/index.js->src/polyfills/fetch.js',
       'src/polyfills/index.js->src/polyfills/get-bounding-client-rect.js',
@@ -443,7 +442,6 @@ exports.rules = [
       'src/friendly-iframe-embed.js->src/polyfills/abort-controller.js',
       'src/friendly-iframe-embed.js->src/polyfills/custom-elements.js',
       'src/friendly-iframe-embed.js->src/polyfills/document-contains.js',
-      'src/friendly-iframe-embed.js->src/polyfills/domtokenlist.js',
       'src/friendly-iframe-embed.js->src/polyfills/intersection-observer.js',
       'src/friendly-iframe-embed.js->src/polyfills/resize-observer.js',
     ],

build-system/test-configs/forbidden-terms.js

@@ -654,7 +654,6 @@ const forbiddenTermsGlobal = {
     message:
       'SVG data images must use charset=utf-8: ' +
       '"data:image/svg+xml;charset=utf-8,..."',
-    allowlist: ['src/service/ie-intrinsic-bug.js'],
   },
   'new CustomEvent\\(': {
     message: 'Use createCustomEvent() helper instead.',

src/core/dom/img.js

@@ -15,24 +15,3 @@ export function guaranteeSrcForSrcsetUnsupportedBrowsers(img) {
     img.setAttribute('src', srcseturl);
   }
 }
-
-/**
- * Generates a transparent PNG of a given width/height.
- *
- * @param {!Document} doc
- * @param {number} width
- * @param {number} height
- * @return {string}
- */
-export function transparentPng(doc, width, height) {
-  const canvas = /** @type {!HTMLCanvasElement} */ (
-    doc.createElement('canvas')
-  );
-  canvas.width = width;
-  canvas.height = height;
-
-  // Canvases are fully transparent by default, so we don't actually need to
-  // draw anything.
-
-  return canvas.toDataURL();
-}

src/custom-element.js

@@ -1175,10 +1175,7 @@ function createBaseCustomElementClass(win, elementConnectedCallback) {
         this.everAttached = true;
 
         try {
-          this.layout_ = applyStaticLayout(
-            this,
-            Services.platformFor(toWin(this.ownerDocument.defaultView)).isIe()
-          );
+          this.layout_ = applyStaticLayout(this);
           this.initMediaAttrs_();
         } catch (e) {
           reportError(e, this);

src/friendly-iframe-embed.js

@@ -19,7 +19,6 @@ import {toWin} from '#core/window';
 import {install as installAbortController} from '#polyfills/abort-controller';
 import {install as installCustomElements} from '#polyfills/custom-elements';
 import {install as installDocContains} from '#polyfills/document-contains';
-import {install as installDOMTokenList} from '#polyfills/domtokenlist';
 import {installForChildWin as installIntersectionObserver} from '#polyfills/intersection-observer';
 import {installForChildWin as installResizeObserver} from '#polyfills/resize-observer';
 
@@ -686,7 +685,6 @@ export class FriendlyIframeEmbed {
 function installPolyfillsInChildWindow(parentWin, childWin) {
   if (!mode.isEsm()) {
     installDocContains(childWin);
-    installDOMTokenList(childWin);
   }
   // The anonymous class parameter allows us to detect native classes vs
   // transpiled classes.

src/polyfills/index.js

@@ -6,7 +6,6 @@ import {install as installAbortController} from './abort-controller';
 import {install as installArrayIncludes} from './array-includes';
 import {install as installCustomElements} from './custom-elements';
 import {install as installDocContains} from './document-contains';
-import {install as installDOMTokenList} from './domtokenlist';
 import {install as installFetch} from './fetch';
 import {install as installGetBoundingClientRect} from './get-bounding-client-rect';
 import {install as installIntersectionObserver} from './intersection-observer';
@@ -36,7 +35,6 @@ if (!mode.isEsm()) {
 // Polyfills that depend on DOM availability
 if (self.document) {
   if (!mode.isEsm()) {
-    installDOMTokenList(self);
     installDocContains(self);
     installGetBoundingClientRect(self);
   }

src/service/navigation.js

@@ -1,8 +1,7 @@
 import {PriorityQueue} from '#core/data-structures/priority-queue';
-import {isIframed, tryFocus} from '#core/dom';
+import {isIframed} from '#core/dom';
 import {escapeCssSelectorIdent} from '#core/dom/css-selectors';
 import {closestAncestorElementBySelector} from '#core/dom/query';
-import * as mode from '#core/mode';
 import {dict} from '#core/types/object';
 import {toWin} from '#core/window';
 
@@ -599,23 +598,6 @@ export class Navigation {
    * @private
    */
   handleHashNavigation_(e, toLocation, fromLocation) {
-    // Anchor navigation in IE doesn't change input focus, which can result in
-    // confusing behavior e.g. when pressing "tab" button.
-    // @see https://humanwhocodes.com/blog/2013/01/15/fixing-skip-to-content-links/
-    // @see https://github.com/ampproject/amphtml/issues/18671
-    if (!mode.isEsm() && Services.platformFor(this.ampdoc.win).isIe()) {
-      const id = toLocation.hash.substring(1);
-      const elementWithId = this.ampdoc.getElementById(id);
-      if (elementWithId) {
-        if (
-          !/^(?:a|select|input|button|textarea)$/i.test(elementWithId.tagName)
-        ) {
-          elementWithId.tabIndex = -1;
-        }
-        tryFocus(elementWithId);
-      }
-    }
-
     // We prevent default so that the current click does not push
     // into the history stack as this messes up the external documents
     // history which contains the amp document.

src/service/platform-impl.js

@@ -1,5 +1,3 @@
-import * as mode from '#core/mode';
-
 import {registerServiceBuilder} from '../service-helpers';
 
 /**
@@ -42,7 +40,6 @@ export class Platform {
     return (
       /Safari/i.test(this.navigator_.userAgent) &&
       !this.isChrome() &&
-      !this.isIe() &&
       !this.isEdge() &&
       !this.isFirefox() &&
       !this.isOpera()
@@ -81,17 +78,6 @@ export class Platform {
     return /OPR\/|Opera|OPiOS/i.test(this.navigator_.userAgent);
   }
 
-  /**
-   * Whether the current browser is a IE browser.
-   * @return {boolean}
-   */
-  isIe() {
-    if (mode.isEsm()) {
-      return false;
-    }
-    return /Trident|MSIE|IEMobile/i.test(this.navigator_.userAgent);
-  }
-
   /**
    * Whether the current browser is an Edge browser.
    * @return {boolean}
@@ -155,9 +141,6 @@ export class Platform {
     if (this.isOpera()) {
       return this.evalMajorVersion_(/(OPR|Opera|OPiOS)\/(\d+)/, 2);
     }
-    if (this.isIe()) {
-      return this.evalMajorVersion_(/MSIE\s(\d+)/, 1);
-    }
     if (this.isEdge()) {
       return this.evalMajorVersion_(/Edge\/(\d+)/, 1);
     }

src/service/resources-impl.js

@@ -10,8 +10,6 @@ import {dict} from '#core/types/object';
 
 import {Services} from '#service';
 
-import {ieIntrinsicCheckAndFix} from './ie-intrinsic-bug';
-import {ieMediaCheckAndFix} from './ie-media-bug';
 import {Resource, ResourceState} from './resource';
 import {READY_SCAN_SIGNAL, ResourcesInterface} from './resources-interface';
 import {TaskQueue} from './task-queue';
@@ -242,16 +240,8 @@ export class ResourcesImpl {
         return;
       }
 
-      ieIntrinsicCheckAndFix(this.win);
-
-      const fixPromise = ieMediaCheckAndFix(this.win);
       const remeasure = () => this.remeasurePass_.schedule();
-      if (fixPromise) {
-        fixPromise.then(remeasure);
-      } else {
-        // No promise means that there's no problem.
-        remeasure();
-      }
+      remeasure();
 
       // Safari 10 and under incorrectly estimates font spacing for
       // `@font-face` fonts. This leads to wild measurement errors. The best