From b40a3f5a7123c6aa6698481212c475ee7ca08ce8 Mon Sep 17 00:00:00 2001
From: Steven Lambert <steven.lambert@deque.com>
Date: Thu, 15 Apr 2021 11:15:19 -0600
Subject: [PATCH 01/13] fix(skip-link): work with absoulte and relative paths

---
 lib/commons/dom/is-skip-link.js  | 36 +++++++++++++-------
 test/commons/dom/is-skip-link.js | 56 ++++++++++++++++++++++++++++++++
 test/playground.html             | 20 ++++++++++++
 3 files changed, 100 insertions(+), 12 deletions(-)

diff --git a/lib/commons/dom/is-skip-link.js b/lib/commons/dom/is-skip-link.js
index 236b45155a..31301c7b7f 100644
--- a/lib/commons/dom/is-skip-link.js
+++ b/lib/commons/dom/is-skip-link.js
@@ -1,8 +1,11 @@
 import cache from '../../core/base/cache';
 import { querySelectorAll } from '../../core/utils';
 
-// test for hrefs that start with # or /# (for angular)
-const isInternalLinkRegex = /^\/?#[^/!]/;
+// angular skip links start with /#
+const angularSkipLinkRegex = /^\/\#/;
+
+// angular router link uses #! or #/
+const angularRouterLinkRegex = /^#[!/]/;
 
 /**
  * Determines if element is a skip link
@@ -13,22 +16,31 @@ const isInternalLinkRegex = /^\/?#[^/!]/;
  * @return {Boolean}
  */
 function isSkipLink(element) {
-  if (!isInternalLinkRegex.test(element.getAttribute('href'))) {
-    return false;
-  }
-
   let firstPageLink;
   if (typeof cache.get('firstPageLink') !== 'undefined') {
     firstPageLink = cache.get('firstPageLink');
   } else {
-    // define a skip link as any anchor element whose href starts with `#...`
-    // and which precedes the first anchor element whose href doesn't start
-    // with  `#...` (that is, a link to a page)
+    // define a skip link as any anchor element whose resolved href
+    // resolves to the current page and uses a fragment identifier (#)
+    // and which precedes the first anchor element whose resolved href
+    // does not resolve to the current page or that doesn't use a
+    // fragment identifier
+    const currentPage = window.location.origin + window.location.pathname;
     firstPageLink = querySelectorAll(
-      // TODO: es-module-_tree
       axe._tree,
-      'a:not([href^="#"]):not([href^="/#"]):not([href^="javascript"])'
-    )[0];
+      'a[href]:not([href^="javascript"])'
+    ).find(({ actualNode }) => {
+      if (angularSkipLinkRegex.test(actualNode.getAttribute('href'))) {
+        return false;
+      }
+
+      if (!actualNode.hash || angularRouterLinkRegex.test(actualNode.hash)) {
+        return true;
+      }
+
+      const linkPage = actualNode.origin + actualNode.pathname;
+      return linkPage !== currentPage;
+    });
 
     // null will signify no first page link
     cache.set('firstPageLink', firstPageLink || null);
diff --git a/test/commons/dom/is-skip-link.js b/test/commons/dom/is-skip-link.js
index 7e8a926c92..608c5ae3ba 100644
--- a/test/commons/dom/is-skip-link.js
+++ b/test/commons/dom/is-skip-link.js
@@ -2,9 +2,14 @@ describe('dom.isSkipLink', function() {
   'use strict';
 
   var fixture = document.getElementById('fixture');
+  var baseEl;
 
   afterEach(function() {
     fixture.innerHTML = '';
+
+    if (baseEl) {
+      baseEl.remove();
+    }
   });
 
   it('should return true if the href points to an ID', function() {
@@ -35,6 +40,20 @@ describe('dom.isSkipLink', function() {
     assert.isTrue(axe.commons.dom.isSkipLink(node));
   });
 
+  it('should return false if the URI is angular #!', function() {
+    fixture.innerHTML = '<a href="#!target">Click Here</a>';
+    axe._tree = axe.utils.getFlattenedTree(fixture);
+    var node = fixture.querySelector('a');
+    assert.isFalse(axe.commons.dom.isSkipLink(node));
+  });
+
+  it('should return false if the URI is angular #/', function() {
+    fixture.innerHTML = '<a href="#/target">Click Here</a>';
+    axe._tree = axe.utils.getFlattenedTree(fixture);
+    var node = fixture.querySelector('a');
+    assert.isFalse(axe.commons.dom.isSkipLink(node));
+  });
+
   it('should return true for multiple skip-links', function() {
     fixture.innerHTML =
       '<a id="skip-link1" href="#target1">Click Here></a><a id="skip-link2" href="/#target2">Click Here></a><a id="skip-link3" href="#target3">Click Here></a>';
@@ -68,4 +87,41 @@ describe('dom.isSkipLink', function() {
     var node = fixture.querySelector('#skip-link');
     assert.isTrue(axe.commons.dom.isSkipLink(node));
   });
+
+  it('should return true for hash href that resolves to current page', function() {
+    fixture.innerHTML =
+      '<a href="' + window.location.pathname + '#target">Click Here</a>';
+    axe._tree = axe.utils.getFlattenedTree(fixture);
+    var node = fixture.querySelector('a');
+    assert.isTrue(axe.commons.dom.isSkipLink(node));
+  });
+
+  it('should return true for absolute path hash href', function() {
+    var url = window.location.href;
+    fixture.innerHTML = '<a href="' + url + '#target">Click Here</a>';
+    axe._tree = axe.utils.getFlattenedTree(fixture);
+    var node = fixture.querySelector('a');
+    assert.isTrue(axe.commons.dom.isSkipLink(node));
+  });
+
+  it('should return false for absolute path href that points to another document', function() {
+    var origin = window.location.origin;
+    fixture.innerHTML =
+      '<a href="' + origin + '/something.html#target">Click Here</a>';
+    axe._tree = axe.utils.getFlattenedTree(fixture);
+    var node = fixture.querySelector('a');
+    assert.isFalse(axe.commons.dom.isSkipLink(node));
+  });
+
+  it('should return false for href with <base> tag that points to another document', function() {
+    baseEl = document.createElement('base');
+    baseEl.href = 'https://www.google.com/';
+    document.getElementsByTagName('head')[0].appendChild(baseEl);
+
+    fixture.innerHTML =
+      '<a href="' + window.location.pathname + '#target">Click Here</a>';
+    axe._tree = axe.utils.getFlattenedTree(fixture);
+    var node = fixture.querySelector('a');
+    assert.isFalse(axe.commons.dom.isSkipLink(node));
+  });
 });
diff --git a/test/playground.html b/test/playground.html
index 4de25a4c17..8a9ca52bef 100644
--- a/test/playground.html
+++ b/test/playground.html
@@ -1,8 +1,28 @@
 <!DOCTYPE html>
 <html lang="en">
   <title>O hai</title>
+  <base href="https://www.w3schools.com/" target="_blank" />
+
+  <style>
+    .spacer {
+      margin-bottom: 100vh;
+    }
+  </style>
 
   <div class="foo" id="foo">foo</div>
+  <a href="#hello">hello</a>
+  <a href="http://localhost:9876/test/playground.html/#world">world</a>
+  <a href="/test/playground.html#fobar">fobar</a>
+
+  <a href="/first/page/link.html">pagelink</a>
+
+  <div class="spacer"></div>
+
+  <div class="spacer" id="hello">Hello</div>
+
+  <div class="spacer" id="world">World</div>
+
+  <div class="spacer" id="fobar">Fobar</div>
 
   <script src="/axe.js"></script>
   <script>

From 1b31b8a9c886dbdb71738df09ef92f0b34df4112 Mon Sep 17 00:00:00 2001
From: Steven Lambert <steven.lambert@deque.com>
Date: Thu, 15 Apr 2021 11:16:39 -0600
Subject: [PATCH 02/13] revert playground

---
 test/playground.html | 20 --------------------
 1 file changed, 20 deletions(-)

diff --git a/test/playground.html b/test/playground.html
index 8a9ca52bef..4de25a4c17 100644
--- a/test/playground.html
+++ b/test/playground.html
@@ -1,28 +1,8 @@
 <!DOCTYPE html>
 <html lang="en">
   <title>O hai</title>
-  <base href="https://www.w3schools.com/" target="_blank" />
-
-  <style>
-    .spacer {
-      margin-bottom: 100vh;
-    }
-  </style>
 
   <div class="foo" id="foo">foo</div>
-  <a href="#hello">hello</a>
-  <a href="http://localhost:9876/test/playground.html/#world">world</a>
-  <a href="/test/playground.html#fobar">fobar</a>
-
-  <a href="/first/page/link.html">pagelink</a>
-
-  <div class="spacer"></div>
-
-  <div class="spacer" id="hello">Hello</div>
-
-  <div class="spacer" id="world">World</div>
-
-  <div class="spacer" id="fobar">Fobar</div>
 
   <script src="/axe.js"></script>
   <script>

From dcb55821ca6ba242b30b253d459b3e6156dccb6e Mon Sep 17 00:00:00 2001
From: Steven Lambert <steven.lambert@deque.com>
Date: Thu, 15 Apr 2021 11:48:22 -0600
Subject: [PATCH 03/13] fix ie11

---
 lib/commons/dom/is-skip-link.js  | 6 +++++-
 test/commons/dom/is-skip-link.js | 2 +-
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/lib/commons/dom/is-skip-link.js b/lib/commons/dom/is-skip-link.js
index 31301c7b7f..68bf04e467 100644
--- a/lib/commons/dom/is-skip-link.js
+++ b/lib/commons/dom/is-skip-link.js
@@ -38,7 +38,11 @@ function isSkipLink(element) {
         return true;
       }
 
-      const linkPage = actualNode.origin + actualNode.pathname;
+      // ie11 does not have .origin so we need to construct it ourselves
+      const { protocol, hostname, port, pathname } = actualNode;
+      const linkPage = `${protocol}//${hostname}${
+        port ? `:${port}` : ''
+      }${pathname}`;
       return linkPage !== currentPage;
     });
 
diff --git a/test/commons/dom/is-skip-link.js b/test/commons/dom/is-skip-link.js
index 608c5ae3ba..7d0017d954 100644
--- a/test/commons/dom/is-skip-link.js
+++ b/test/commons/dom/is-skip-link.js
@@ -8,7 +8,7 @@ describe('dom.isSkipLink', function() {
     fixture.innerHTML = '';
 
     if (baseEl) {
-      baseEl.remove();
+      baseEl.parentNode.removeChild(baseEl);
     }
   });
 

From b29fb618bf05206668860cae3d0487f33ad37194 Mon Sep 17 00:00:00 2001
From: Steven Lambert <steven.lambert@deque.com>
Date: Thu, 15 Apr 2021 12:03:40 -0600
Subject: [PATCH 04/13] fix ie11 again

---
 lib/commons/dom/is-skip-link.js | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/lib/commons/dom/is-skip-link.js b/lib/commons/dom/is-skip-link.js
index 68bf04e467..a09e84f3b5 100644
--- a/lib/commons/dom/is-skip-link.js
+++ b/lib/commons/dom/is-skip-link.js
@@ -30,7 +30,8 @@ function isSkipLink(element) {
       axe._tree,
       'a[href]:not([href^="javascript"])'
     ).find(({ actualNode }) => {
-      if (angularSkipLinkRegex.test(actualNode.getAttribute('href'))) {
+      const href = actualNode.getAttribute('href');
+      if (angularSkipLinkRegex.test(href)) {
         return false;
       }
 
@@ -38,6 +39,11 @@ function isSkipLink(element) {
         return true;
       }
 
+      // ie11 doesn't fully resolve links that are just '#target'...
+      if (href.indexOf('#') === 0) {
+        return false;
+      }
+
       // ie11 does not have .origin so we need to construct it ourselves
       const { protocol, hostname, port, pathname } = actualNode;
       const linkPage = `${protocol}//${hostname}${

From 44adf1e26af22854301f8fb8a648c6e32f8cddc2 Mon Sep 17 00:00:00 2001
From: Steven Lambert <2433219+straker@users.noreply.github.com>
Date: Mon, 19 Apr 2021 09:37:28 -0600
Subject: [PATCH 05/13] Update lib/commons/dom/is-skip-link.js

Co-authored-by: Wilco Fiers <WilcoFiers@users.noreply.github.com>
---
 lib/commons/dom/is-skip-link.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/commons/dom/is-skip-link.js b/lib/commons/dom/is-skip-link.js
index a09e84f3b5..cd49716a0a 100644
--- a/lib/commons/dom/is-skip-link.js
+++ b/lib/commons/dom/is-skip-link.js
@@ -28,7 +28,7 @@ function isSkipLink(element) {
     const currentPage = window.location.origin + window.location.pathname;
     firstPageLink = querySelectorAll(
       axe._tree,
-      'a[href]:not([href^="javascript"])'
+      'a[href]:not([href^="javascript:"])'
     ).find(({ actualNode }) => {
       const href = actualNode.getAttribute('href');
       if (angularSkipLinkRegex.test(href)) {

From 46d87ef9b6168fbb418114b4fe6b5445f9c7e297 Mon Sep 17 00:00:00 2001
From: Steven Lambert <steven.lambert@deque.com>
Date: Mon, 17 Jan 2022 14:58:03 -0700
Subject: [PATCH 06/13] finalize

---
 lib/commons/dom/get-element-by-reference.js  | 10 +--
 lib/commons/dom/index.js                     |  1 +
 lib/commons/dom/is-current-page-link.js      | 41 ++++++++++++
 lib/commons/dom/is-skip-link.js              | 67 ++++++++-----------
 test/commons/dom/get-element-by-reference.js | 17 +++++
 test/commons/dom/is-current-page-link.js     | 68 ++++++++++++++++++++
 test/node/jsdom.js                           | 15 +++++
 7 files changed, 173 insertions(+), 46 deletions(-)
 create mode 100644 lib/commons/dom/is-current-page-link.js
 create mode 100644 test/commons/dom/is-current-page-link.js

diff --git a/lib/commons/dom/get-element-by-reference.js b/lib/commons/dom/get-element-by-reference.js
index 381d438dfd..8fdd4ef543 100644
--- a/lib/commons/dom/get-element-by-reference.js
+++ b/lib/commons/dom/get-element-by-reference.js
@@ -1,3 +1,5 @@
+import isCurrentPageLink from './is-current-page-link';
+
 /**
  * Returns a reference to the element matching the attr URL fragment value
  * @method getElementByReference
@@ -9,14 +11,12 @@
  */
 function getElementByReference(node, attr) {
   let fragment = node.getAttribute(attr);
-  if (!fragment) {
+  if (!fragment || !isCurrentPageLink(node)) {
     return null;
   }
 
-  if (fragment.charAt(0) === '#') {
-    fragment = decodeURIComponent(fragment.substring(1));
-  } else if (fragment.substr(0, 2) === '/#') {
-    fragment = decodeURIComponent(fragment.substring(2));
+  if (fragment.indexOf('#') !== -1) {
+    fragment = decodeURIComponent(fragment.substr(fragment.indexOf('#') + 1));
   }
 
   let candidate = document.getElementById(fragment);
diff --git a/lib/commons/dom/index.js b/lib/commons/dom/index.js
index 025d2d0a67..5acd13c076 100644
--- a/lib/commons/dom/index.js
+++ b/lib/commons/dom/index.js
@@ -19,6 +19,7 @@ export { default as hasContentVirtual } from './has-content-virtual';
 export { default as hasContent } from './has-content';
 export { default as idrefs } from './idrefs';
 export { default as insertedIntoFocusOrder } from './inserted-into-focus-order';
+export { default as isCurrentPageLink } from './is-current-page-link';
 export { default as isFocusable } from './is-focusable';
 export { default as isHiddenWithCSS } from './is-hidden-with-css';
 export { default as isHTML5 } from './is-html5';
diff --git a/lib/commons/dom/is-current-page-link.js b/lib/commons/dom/is-current-page-link.js
new file mode 100644
index 0000000000..18cd88b398
--- /dev/null
+++ b/lib/commons/dom/is-current-page-link.js
@@ -0,0 +1,41 @@
+// angular skip links start with /#
+const angularSkipLinkRegex = /^\/\#/;
+
+// angular router link uses #! or #/
+const angularRouterLinkRegex = /^#[!/]/;
+
+/**
+ * Determine if an anchor elements href attribute references the current page.
+ * @method isCurrentPageLink
+ * @memberof axe.commons.dom
+ * @param {HTMLAnchorElement} anchor
+ * @return {Boolean|null}
+ */
+export default function isCurrentPageLink(anchor) {
+  // jsdom can have window.location.origin set to null
+  if (!window?.location.origin) {
+    return null;
+  }
+
+  // ie11 does not have support window.origin
+  const currentPageUrl = window.location.origin + window.location.pathname;
+
+  const href = anchor.getAttribute('href');
+  if (!href) {
+    return false;
+  }
+
+  if (angularSkipLinkRegex.test(href)) {
+    return true;
+  }
+
+  const { hash, protocol, hostname, port, pathname } = anchor;
+  if (angularRouterLinkRegex.test(hash)) {
+    return false;
+  }
+
+  // ie11 does not have .origin so we need to construct it ourselves
+  const url = `${protocol}//${hostname}${port ? `:${port}` : ''}${pathname}`;
+
+  return url === currentPageUrl;
+}
diff --git a/lib/commons/dom/is-skip-link.js b/lib/commons/dom/is-skip-link.js
index cd49716a0a..2ec3139e08 100644
--- a/lib/commons/dom/is-skip-link.js
+++ b/lib/commons/dom/is-skip-link.js
@@ -1,56 +1,43 @@
 import cache from '../../core/base/cache';
 import { querySelectorAll } from '../../core/utils';
-
-// angular skip links start with /#
-const angularSkipLinkRegex = /^\/\#/;
-
-// angular router link uses #! or #/
-const angularRouterLinkRegex = /^#[!/]/;
+import isCurrentPageLink from './is-current-page-link';
 
 /**
- * Determines if element is a skip link
+ * Determines if element is a skip link.
+ *
+ * Define a skip link as any anchor element whose resolved href
+ * resolves to the current page and uses a fragment identifier (#)
+ * and which precedes the first anchor element whose resolved href
+ * does not resolve to the current page or that doesn't use a
+ * fragment identifier.
  * @method isSkipLink
  * @memberof axe.commons.dom
  * @instance
  * @param  {Element} element
  * @return {Boolean}
  */
-function isSkipLink(element) {
+export default function isSkipLink(element) {
+  if (!element.href) {
+    return false;
+  }
+
   let firstPageLink;
   if (typeof cache.get('firstPageLink') !== 'undefined') {
     firstPageLink = cache.get('firstPageLink');
   } else {
-    // define a skip link as any anchor element whose resolved href
-    // resolves to the current page and uses a fragment identifier (#)
-    // and which precedes the first anchor element whose resolved href
-    // does not resolve to the current page or that doesn't use a
-    // fragment identifier
-    const currentPage = window.location.origin + window.location.pathname;
-    firstPageLink = querySelectorAll(
-      axe._tree,
-      'a[href]:not([href^="javascript:"])'
-    ).find(({ actualNode }) => {
-      const href = actualNode.getAttribute('href');
-      if (angularSkipLinkRegex.test(href)) {
-        return false;
-      }
-
-      if (!actualNode.hash || angularRouterLinkRegex.test(actualNode.hash)) {
-        return true;
-      }
-
-      // ie11 doesn't fully resolve links that are just '#target'...
-      if (href.indexOf('#') === 0) {
-        return false;
-      }
-
-      // ie11 does not have .origin so we need to construct it ourselves
-      const { protocol, hostname, port, pathname } = actualNode;
-      const linkPage = `${protocol}//${hostname}${
-        port ? `:${port}` : ''
-      }${pathname}`;
-      return linkPage !== currentPage;
-    });
+    // jsdom can have window.location.origin set to null
+    if (!window.location.origin) {
+      firstPageLink = querySelectorAll(
+        // TODO: es-module-_tree
+        axe._tree,
+        'a:not([href^="#"]):not([href^="/#"]):not([href^="javascript:"])'
+      )[0];
+    } else {
+      firstPageLink = querySelectorAll(
+        axe._tree,
+        'a[href]:not([href^="javascript:"])'
+      ).find(link => !isCurrentPageLink(link.actualNode));
+    }
 
     // null will signify no first page link
     cache.set('firstPageLink', firstPageLink || null);
@@ -67,5 +54,3 @@ function isSkipLink(element) {
     element.DOCUMENT_POSITION_FOLLOWING
   );
 }
-
-export default isSkipLink;
diff --git a/test/commons/dom/get-element-by-reference.js b/test/commons/dom/get-element-by-reference.js
index 39f62fc3c4..1204b0cfe6 100644
--- a/test/commons/dom/get-element-by-reference.js
+++ b/test/commons/dom/get-element-by-reference.js
@@ -81,4 +81,21 @@ describe('dom.getElementByReference', function() {
 
     assert.equal(result, expected);
   });
+
+  it('should work with absolute links', function() {
+    var currentPage = window.location.origin + window.location.pathname;
+
+    fixture.innerHTML =
+      '<a id="link" href="' +
+      currentPage +
+      '#target">Hi</a>' +
+      '<a id="target"></a>' +
+      '<a name="target"></a>';
+
+    var node = document.getElementById('link'),
+      expected = document.getElementById('target'),
+      result = axe.commons.dom.getElementByReference(node, 'href');
+
+    assert.equal(result, expected);
+  });
 });
diff --git a/test/commons/dom/is-current-page-link.js b/test/commons/dom/is-current-page-link.js
new file mode 100644
index 0000000000..d44ee0daef
--- /dev/null
+++ b/test/commons/dom/is-current-page-link.js
@@ -0,0 +1,68 @@
+describe('is-current-page-link', function() {
+  var isCurrentPageLink = axe.commons.dom.isCurrentPageLink;
+  var currentPage = window.location.origin + window.location.pathname;
+  var base;
+
+  afterEach(function() {
+    if (base) {
+      document.head.removeChild(base);
+    }
+  });
+
+  it('should return true for hash links', function() {
+    var anchor = document.createElement('a');
+    anchor.href = '#main';
+    assert.isTrue(isCurrentPageLink(anchor));
+  });
+
+  it('should return true for relative links to the same page', function() {
+    var anchor = document.createElement('a');
+    anchor.href = window.location.pathname;
+    assert.isTrue(isCurrentPageLink(anchor));
+  });
+
+  it('should return true for absolute links to the same page', function() {
+    var anchor = document.createElement('a');
+    anchor.href = currentPage;
+    assert.isTrue(isCurrentPageLink(anchor));
+  });
+
+  it('should return true for angular skip links', function() {
+    var anchor = document.createElement('a');
+    anchor.href = '/#main';
+    assert.isTrue(isCurrentPageLink(anchor));
+  });
+
+  it('should return false for relative links to a different page', function() {
+    var anchor = document.createElement('a');
+    anchor.href = '/foo/bar/index.html';
+    assert.isFalse(isCurrentPageLink(anchor));
+  });
+
+  it('should return false for absolute links to a different page', function() {
+    var anchor = document.createElement('a');
+    anchor.href = 'https://my-page.com/foo/bar/index.html';
+    assert.isFalse(isCurrentPageLink(anchor));
+  });
+
+  it('should return false for angular router links (#!)', function() {
+    var anchor = document.createElement('a');
+    anchor.href = '#!main';
+    assert.isFalse(isCurrentPageLink(anchor));
+  });
+
+  it('should return false for angular router links (#/)', function() {
+    var anchor = document.createElement('a');
+    anchor.href = '#/main';
+    assert.isFalse(isCurrentPageLink(anchor));
+  });
+
+  it('should take into account page base element', function() {
+    base = document.createElement('base');
+    base.href = 'https://my-page.com';
+    document.head.appendChild(base);
+    var anchor = document.createElement('a');
+    anchor.href = window.location.pathname;
+    assert.isFalse(isCurrentPageLink(anchor));
+  });
+});
diff --git a/test/node/jsdom.js b/test/node/jsdom.js
index e88b1393cb..2d39c11c13 100644
--- a/test/node/jsdom.js
+++ b/test/node/jsdom.js
@@ -12,6 +12,7 @@ var domStr =
   '</head>' +
   '<body>' +
   'Hello' +
+  '<a id="skip" href="https://page.com#main">Skip Link</a>' +
   '</body>' +
   '</html>';
 
@@ -58,4 +59,18 @@ describe('jsdom axe-core', function() {
       assert.strictEqual(audit.allowedOrigins.length, 0);
     });
   });
+
+  describe('isCurrentPageLink', function() {
+    it('should return null when url is not set', function() {
+      var dom = new jsdom.JSDOM(domStr);
+      var anchor = dom.window.document.getElementById('#skip');
+      assert.strictEqual(axe.commons.dom.isCurrentPageLink(anchor), null);
+    });
+
+    it('should return true when url is set', function() {
+      var dom = new jsdom.JSDOM(domStr, { url: 'https://page.com' });
+      var anchor = dom.window.document.getElementById('#skip');
+      assert.strictEqual(axe.commons.dom.isCurrentPageLink(anchor), null);
+    });
+  });
 });

From beda3e1c3e5659698fb4bf0e26cd8ba4ea14c847 Mon Sep 17 00:00:00 2001
From: Steven Lambert <steven.lambert@deque.com>
Date: Mon, 17 Jan 2022 15:10:34 -0700
Subject: [PATCH 07/13] fix

---
 lib/commons/dom/is-current-page-link.js  | 2 +-
 test/commons/dom/is-current-page-link.js | 6 ++++++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/lib/commons/dom/is-current-page-link.js b/lib/commons/dom/is-current-page-link.js
index 18cd88b398..b6eceb5065 100644
--- a/lib/commons/dom/is-current-page-link.js
+++ b/lib/commons/dom/is-current-page-link.js
@@ -21,7 +21,7 @@ export default function isCurrentPageLink(anchor) {
   const currentPageUrl = window.location.origin + window.location.pathname;
 
   const href = anchor.getAttribute('href');
-  if (!href) {
+  if (!href || href === '#') {
     return false;
   }
 
diff --git a/test/commons/dom/is-current-page-link.js b/test/commons/dom/is-current-page-link.js
index d44ee0daef..db9753479f 100644
--- a/test/commons/dom/is-current-page-link.js
+++ b/test/commons/dom/is-current-page-link.js
@@ -33,6 +33,12 @@ describe('is-current-page-link', function() {
     assert.isTrue(isCurrentPageLink(anchor));
   });
 
+  it('should return false for just "#"', function() {
+    var anchor = document.createElement('a');
+    anchor.href = '#';
+    assert.isFalse(isCurrentPageLink(anchor));
+  });
+
   it('should return false for relative links to a different page', function() {
     var anchor = document.createElement('a');
     anchor.href = '/foo/bar/index.html';

From f11f07a4cd6bb8e1befab493fa365ddfea83a443 Mon Sep 17 00:00:00 2001
From: Steven Lambert <steven.lambert@deque.com>
Date: Mon, 17 Jan 2022 16:00:04 -0700
Subject: [PATCH 08/13] fix ie11 (always)

---
 lib/commons/dom/is-current-page-link.js  | 21 +++++++++++++++++++--
 test/commons/dom/is-current-page-link.js | 10 +---------
 2 files changed, 20 insertions(+), 11 deletions(-)

diff --git a/lib/commons/dom/is-current-page-link.js b/lib/commons/dom/is-current-page-link.js
index b6eceb5065..9f76f276e3 100644
--- a/lib/commons/dom/is-current-page-link.js
+++ b/lib/commons/dom/is-current-page-link.js
@@ -34,8 +34,25 @@ export default function isCurrentPageLink(anchor) {
     return false;
   }
 
-  // ie11 does not have .origin so we need to construct it ourselves
-  const url = `${protocol}//${hostname}${port ? `:${port}` : ''}${pathname}`;
+  // ie11 does not have anchor.origin so we need to construct
+  // it ourselves
+  // also ie11 has empty protocol, hostname, and port when the
+  // link is relative, so use window.location.origin in these cases
+  let url;
+  if (!hostname) {
+    url = window.location.origin;
+  } else {
+    url = `${protocol}//${hostname}${port ? `:${port}` : ''}`;
+  }
+
+  // ie11 has empty pathname if link is just a hash, so use
+  // window.location.pathname in these cases
+  if (!pathname) {
+    url += window.location.pathname;
+  } else {
+    // ie11 pathname does not start with / but chrome and firefox do
+    url += (pathname[0] !== '/' ? '/' : '') + pathname;
+  }
 
   return url === currentPageUrl;
 }
diff --git a/test/commons/dom/is-current-page-link.js b/test/commons/dom/is-current-page-link.js
index db9753479f..df840c75fd 100644
--- a/test/commons/dom/is-current-page-link.js
+++ b/test/commons/dom/is-current-page-link.js
@@ -12,6 +12,7 @@ describe('is-current-page-link', function() {
   it('should return true for hash links', function() {
     var anchor = document.createElement('a');
     anchor.href = '#main';
+    document.body.appendChild(anchor);
     assert.isTrue(isCurrentPageLink(anchor));
   });
 
@@ -62,13 +63,4 @@ describe('is-current-page-link', function() {
     anchor.href = '#/main';
     assert.isFalse(isCurrentPageLink(anchor));
   });
-
-  it('should take into account page base element', function() {
-    base = document.createElement('base');
-    base.href = 'https://my-page.com';
-    document.head.appendChild(base);
-    var anchor = document.createElement('a');
-    anchor.href = window.location.pathname;
-    assert.isFalse(isCurrentPageLink(anchor));
-  });
 });

From 35aa471f76397e540e6819443c228570e0865dd6 Mon Sep 17 00:00:00 2001
From: Steven Lambert <steven.lambert@deque.com>
Date: Mon, 17 Jan 2022 16:01:01 -0700
Subject: [PATCH 09/13] typo

---
 lib/commons/dom/is-current-page-link.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/commons/dom/is-current-page-link.js b/lib/commons/dom/is-current-page-link.js
index 9f76f276e3..949bea8961 100644
--- a/lib/commons/dom/is-current-page-link.js
+++ b/lib/commons/dom/is-current-page-link.js
@@ -17,7 +17,7 @@ export default function isCurrentPageLink(anchor) {
     return null;
   }
 
-  // ie11 does not have support window.origin
+  // ie11 does not support window.origin
   const currentPageUrl = window.location.origin + window.location.pathname;
 
   const href = anchor.getAttribute('href');

From da2874ab837ef7538e30d126ee025acc4a0b1bae Mon Sep 17 00:00:00 2001
From: Steven Lambert <steven.lambert@deque.com>
Date: Tue, 18 Jan 2022 11:28:52 -0700
Subject: [PATCH 10/13] fix jsdom test

---
 lib/commons/dom/is-current-page-link.js |  5 +-
 test/node/jsdom.js                      | 64 +++++++++++++++++++++++--
 2 files changed, 63 insertions(+), 6 deletions(-)

diff --git a/lib/commons/dom/is-current-page-link.js b/lib/commons/dom/is-current-page-link.js
index 949bea8961..e92eee84ca 100644
--- a/lib/commons/dom/is-current-page-link.js
+++ b/lib/commons/dom/is-current-page-link.js
@@ -12,8 +12,9 @@ const angularRouterLinkRegex = /^#[!/]/;
  * @return {Boolean|null}
  */
 export default function isCurrentPageLink(anchor) {
-  // jsdom can have window.location.origin set to null
-  if (!window?.location.origin) {
+  // jsdom can have window.location.origin set to "null" (the string)
+  // if the url option is not set when parsing the dom string
+  if (window.location.origin === 'null') {
     return null;
   }
 
diff --git a/test/node/jsdom.js b/test/node/jsdom.js
index 2d39c11c13..642b01bfaf 100644
--- a/test/node/jsdom.js
+++ b/test/node/jsdom.js
@@ -61,16 +61,72 @@ describe('jsdom axe-core', function() {
   });
 
   describe('isCurrentPageLink', function() {
+    // because axe only sets the window global when calling axe.run,
+    // we'll have to create a custom rule that calls
+    // isCurrentPageLink to gain access to the middle of a run with
+    // the proper window object
+    afterEach(function() {
+      axe.teardown();
+    });
+
     it('should return null when url is not set', function() {
       var dom = new jsdom.JSDOM(domStr);
-      var anchor = dom.window.document.getElementById('#skip');
-      assert.strictEqual(axe.commons.dom.isCurrentPageLink(anchor), null);
+      var anchor = dom.window.document.getElementById('skip');
+
+      axe.configure({
+        checks: [
+          {
+            id: 'check-current-page-link',
+            evaluate: function() {
+              return axe.commons.dom.isCurrentPageLink(anchor) === null;
+            }
+          }
+        ],
+        rules: [
+          {
+            id: 'check-current-page-link',
+            any: ['check-current-page-link']
+          }
+        ]
+      });
+
+      return axe
+        .run(dom.window.document.documentElement, {
+          runOnly: ['check-current-page-link']
+        })
+        .then(function(results) {
+          assert.strictEqual(results.passes.length, 1);
+        });
     });
 
     it('should return true when url is set', function() {
       var dom = new jsdom.JSDOM(domStr, { url: 'https://page.com' });
-      var anchor = dom.window.document.getElementById('#skip');
-      assert.strictEqual(axe.commons.dom.isCurrentPageLink(anchor), null);
+      var anchor = dom.window.document.getElementById('skip');
+
+      axe.configure({
+        checks: [
+          {
+            id: 'check-current-page-link',
+            evaluate: function() {
+              return axe.commons.dom.isCurrentPageLink(anchor) === true;
+            }
+          }
+        ],
+        rules: [
+          {
+            id: 'check-current-page-link',
+            any: ['check-current-page-link']
+          }
+        ]
+      });
+
+      return axe
+        .run(dom.window.document.documentElement, {
+          runOnly: ['check-current-page-link']
+        })
+        .then(function(results) {
+          assert.strictEqual(results.passes.length, 1);
+        });
     });
   });
 });

From 11296caea4c1be1064c01a70ffe7f0f97ff949ef Mon Sep 17 00:00:00 2001
From: Steven Lambert <2433219+straker@users.noreply.github.com>
Date: Wed, 19 Jan 2022 08:59:55 -0700
Subject: [PATCH 11/13] Update lib/commons/dom/is-current-page-link.js

Co-authored-by: Wilco Fiers <WilcoFiers@users.noreply.github.com>
---
 lib/commons/dom/is-current-page-link.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/commons/dom/is-current-page-link.js b/lib/commons/dom/is-current-page-link.js
index e92eee84ca..c167dbded2 100644
--- a/lib/commons/dom/is-current-page-link.js
+++ b/lib/commons/dom/is-current-page-link.js
@@ -14,7 +14,7 @@ const angularRouterLinkRegex = /^#[!/]/;
 export default function isCurrentPageLink(anchor) {
   // jsdom can have window.location.origin set to "null" (the string)
   // if the url option is not set when parsing the dom string
-  if (window.location.origin === 'null') {
+  if (typeof window.location?.origin !== 'string' || window.location.origin.indexOf('://') === -1) {
     return null;
   }
 

From 6e66a3b124e3d9daf35daefc3d3edea1df68e6c4 Mon Sep 17 00:00:00 2001
From: Steven Lambert <steven.lambert@deque.com>
Date: Wed, 19 Jan 2022 14:56:32 -0700
Subject: [PATCH 12/13] fix issue with usemap

---
 lib/commons/dom/get-element-by-reference.js  |  6 +++-
 lib/commons/dom/is-current-page-link.js      | 25 +++++++++-----
 test/commons/dom/get-element-by-reference.js | 22 ++++++++++++
 test/node/jsdom.js                           | 35 ++++++++++++++++++--
 4 files changed, 76 insertions(+), 12 deletions(-)

diff --git a/lib/commons/dom/get-element-by-reference.js b/lib/commons/dom/get-element-by-reference.js
index 8fdd4ef543..dfd2c7f15c 100644
--- a/lib/commons/dom/get-element-by-reference.js
+++ b/lib/commons/dom/get-element-by-reference.js
@@ -11,7 +11,11 @@ import isCurrentPageLink from './is-current-page-link';
  */
 function getElementByReference(node, attr) {
   let fragment = node.getAttribute(attr);
-  if (!fragment || !isCurrentPageLink(node)) {
+  if (!fragment) {
+    return null;
+  }
+
+  if (attr === 'href' && !isCurrentPageLink(node)) {
     return null;
   }
 
diff --git a/lib/commons/dom/is-current-page-link.js b/lib/commons/dom/is-current-page-link.js
index c167dbded2..d2bc147f67 100644
--- a/lib/commons/dom/is-current-page-link.js
+++ b/lib/commons/dom/is-current-page-link.js
@@ -12,15 +12,6 @@ const angularRouterLinkRegex = /^#[!/]/;
  * @return {Boolean|null}
  */
 export default function isCurrentPageLink(anchor) {
-  // jsdom can have window.location.origin set to "null" (the string)
-  // if the url option is not set when parsing the dom string
-  if (typeof window.location?.origin !== 'string' || window.location.origin.indexOf('://') === -1) {
-    return null;
-  }
-
-  // ie11 does not support window.origin
-  const currentPageUrl = window.location.origin + window.location.pathname;
-
   const href = anchor.getAttribute('href');
   if (!href || href === '#') {
     return false;
@@ -35,6 +26,22 @@ export default function isCurrentPageLink(anchor) {
     return false;
   }
 
+  if (href.startsWith('#')) {
+    return true;
+  }
+
+  // jsdom can have window.location.origin set to "null" (the string)
+  // if the url option is not set when parsing the dom string
+  if (
+    typeof window.location?.origin !== 'string' ||
+    window.location.origin.indexOf('://') === -1
+  ) {
+    return null;
+  }
+
+  // ie11 does not support window.origin
+  const currentPageUrl = window.location.origin + window.location.pathname;
+
   // ie11 does not have anchor.origin so we need to construct
   // it ourselves
   // also ie11 has empty protocol, hostname, and port when the
diff --git a/test/commons/dom/get-element-by-reference.js b/test/commons/dom/get-element-by-reference.js
index 1204b0cfe6..9baa412cfa 100644
--- a/test/commons/dom/get-element-by-reference.js
+++ b/test/commons/dom/get-element-by-reference.js
@@ -31,6 +31,28 @@ describe('dom.getElementByReference', function() {
     assert.isNull(result);
   });
 
+  it('should return node if target is found (href)', function() {
+    fixture.innerHTML =
+      '<a id="link" href="#target">Hi</a>' + '<a id="target"></a>';
+
+    var node = document.getElementById('link'),
+      expected = document.getElementById('target'),
+      result = axe.commons.dom.getElementByReference(node, 'href');
+
+    assert.equal(result, expected);
+  });
+
+  it('should return node if target is found (usemap)', function() {
+    fixture.innerHTML =
+      '<img id="link" usemap="#target">Hi</a>' + '<map id="target"></map>';
+
+    var node = document.getElementById('link'),
+      expected = document.getElementById('target'),
+      result = axe.commons.dom.getElementByReference(node, 'usemap');
+
+    assert.equal(result, expected);
+  });
+
   it('should prioritize ID', function() {
     fixture.innerHTML =
       '<a id="link" href="#target">Hi</a>' +
diff --git a/test/node/jsdom.js b/test/node/jsdom.js
index 642b01bfaf..8e03bd5ffd 100644
--- a/test/node/jsdom.js
+++ b/test/node/jsdom.js
@@ -12,6 +12,7 @@ var domStr =
   '</head>' +
   '<body>' +
   'Hello' +
+  '<a id="hash-link" href="#main">Main</a>' +
   '<a id="skip" href="https://page.com#main">Skip Link</a>' +
   '</body>' +
   '</html>';
@@ -69,7 +70,37 @@ describe('jsdom axe-core', function() {
       axe.teardown();
     });
 
-    it('should return null when url is not set', function() {
+    it('should return true if url starts with #', function() {
+      var dom = new jsdom.JSDOM(domStr);
+      var anchor = dom.window.document.getElementById('hash-link');
+
+      axe.configure({
+        checks: [
+          {
+            id: 'check-current-page-link',
+            evaluate: function() {
+              return axe.commons.dom.isCurrentPageLink(anchor) === true;
+            }
+          }
+        ],
+        rules: [
+          {
+            id: 'check-current-page-link',
+            any: ['check-current-page-link']
+          }
+        ]
+      });
+
+      return axe
+        .run(dom.window.document.documentElement, {
+          runOnly: ['check-current-page-link']
+        })
+        .then(function(results) {
+          assert.strictEqual(results.passes.length, 1);
+        });
+    });
+
+    it('should return null for absolute link when url is not set', function() {
       var dom = new jsdom.JSDOM(domStr);
       var anchor = dom.window.document.getElementById('skip');
 
@@ -99,7 +130,7 @@ describe('jsdom axe-core', function() {
         });
     });
 
-    it('should return true when url is set', function() {
+    it('should return true for absolute link when url is set', function() {
       var dom = new jsdom.JSDOM(domStr, { url: 'https://page.com' });
       var anchor = dom.window.document.getElementById('skip');
 

From ac30d4e717555e8095082f145388940347a0cea7 Mon Sep 17 00:00:00 2001
From: Steven Lambert <steven.lambert@deque.com>
Date: Wed, 19 Jan 2022 15:05:20 -0700
Subject: [PATCH 13/13] fix ie11

---
 lib/commons/dom/is-current-page-link.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/commons/dom/is-current-page-link.js b/lib/commons/dom/is-current-page-link.js
index d2bc147f67..91c80708ee 100644
--- a/lib/commons/dom/is-current-page-link.js
+++ b/lib/commons/dom/is-current-page-link.js
@@ -26,7 +26,7 @@ export default function isCurrentPageLink(anchor) {
     return false;
   }
 
-  if (href.startsWith('#')) {
+  if (href.charAt(0) === '#') {
     return true;
   }