fix: avoid problems from element IDs that exist on object prototype

lib/commons/aria/get-accessible-refs.js

@@ -13,22 +13,26 @@ function cacheIdRefs(node, idRefs, refAttrs) {
   if (node.hasAttribute) {
     if (node.nodeName.toUpperCase() === 'LABEL' && node.hasAttribute('for')) {
       const id = node.getAttribute('for');
-      idRefs[id] = idRefs[id] || [];
-      idRefs[id].push(node);
+      if (!idRefs.has(id)) {
+        idRefs.set(id, [node]);
+      } else {
+        idRefs.get(id).push(node);
+      }
     }
 
     for (let i = 0; i < refAttrs.length; ++i) {
       const attr = refAttrs[i];
       const attrValue = sanitize(node.getAttribute(attr) || '');
-
       if (!attrValue) {
         continue;
       }
 
-      const tokens = tokenList(attrValue);
-      for (let k = 0; k < tokens.length; ++k) {
-        idRefs[tokens[k]] = idRefs[tokens[k]] || [];
-        idRefs[tokens[k]].push(node);
+      for (const token of tokenList(attrValue)) {
+        if (!idRefs.has(token)) {
+          idRefs.set(token, [node]);
+        } else {
+          idRefs.get(token).push(node);
+        }
       }
     }
   }
@@ -50,22 +54,21 @@ function getAccessibleRefs(node) {
   let root = getRootNode(node);
   root = root.documentElement || root; // account for shadow roots
 
-  const idRefsByRoot = cache.get('idRefsByRoot', () => new WeakMap());
+  const idRefsByRoot = cache.get('idRefsByRoot', () => new Map());
 
   let idRefs = idRefsByRoot.get(root);
   if (!idRefs) {
-    idRefs = {};
+    idRefs = new Map();
     idRefsByRoot.set(root, idRefs);
 
     const refAttrs = Object.keys(standards.ariaAttrs).filter(attr => {
       const { type } = standards.ariaAttrs[attr];
       return idRefsRegex.test(type);
     });
-
     cacheIdRefs(root, idRefs, refAttrs);
   }
 
-  return idRefs[node.id] || [];
+  return idRefs.get(node.id) ?? [];
 }
 
 export default getAccessibleRefs;

lib/core/utils/find-by.js

@@ -9,7 +9,13 @@
  */
 function findBy(array, key, value) {
   if (Array.isArray(array)) {
-    return array.find(obj => typeof obj === 'object' && obj[key] === value);
+    return array.find(
+      obj =>
+        obj !== null &&
+        typeof obj === 'object' &&
+        Object.hasOwn(obj, key) &&
+        obj[key] === value
+    );
   }
 }
 

lib/core/utils/selector-cache.js

@@ -91,9 +91,12 @@ function findMatchingNodes(expression, selectorMap, shadowId) {
     nodes = selectorMap['*'];
   } else {
     if (exp.id) {
-      // a selector must match all parts, otherwise we can just exit
-      // early
-      if (!selectorMap[idsKey] || !selectorMap[idsKey][exp.id]?.length) {
+      // a selector must match all parts, otherwise we can just exit early
+      if (
+        !selectorMap[idsKey] ||
+        !Object.hasOwn(selectorMap[idsKey], exp.id) ||
+        !selectorMap[idsKey][exp.id]?.length
+      ) {
         return;
       }
 
@@ -176,7 +179,9 @@ function getSharedValues(a, b) {
  * @param {Object} map
  */
 function cacheSelector(key, vNode, map) {
-  map[key] = map[key] || [];
+  if (!Object.hasOwn(map, key)) {
+    map[key] = [];
+  }
   map[key].push(vNode);
 }
 

lib/standards/html-elms.js

@@ -358,7 +358,7 @@ const htmlElms = {
           'menuitem',
           'menuitemcheckbox',
           'menuitemradio',
-	  'meter',
+          'meter',
           'option',
           'progressbar',
           'radio',

test/commons/aria/get-accessible-refs.js

@@ -80,6 +80,34 @@ describe('aria.getAccessibleRefs', function () {
     assert.deepEqual(getAccessibleRefs(node), [ref]);
   });
 
+  describe('when JavaScript object names are used as IDs', function () {
+    const ids = [
+      'prototype',
+      'constructor',
+      '__proto__',
+      'Element',
+      'nodeName',
+      'valueOf',
+      'toString'
+    ];
+    for (const id of ids) {
+      it(`does not break with id="${id}"`, function () {
+        setLookup({ 'aria-bar': { type: 'idrefs' } });
+        fixture.innerHTML = `<div id="ref" aria-bar="${ids.join(
+          ' '
+        )}"></div><i id="${id}"></i>`;
+
+        var node = document.getElementById(id);
+        var ref = document.getElementById('ref');
+        assert.deepEqual(
+          getAccessibleRefs(node),
+          [ref],
+          `Not equal for ID ${id}`
+        );
+      });
+    }
+  });
+
   (shadowSupport ? it : xit)('works inside shadow DOM', function () {
     setLookup({ 'aria-bar': { type: 'idref' } });
     fixture.innerHTML = '<div id="foo"></div>';

test/core/utils/find-by.js

@@ -40,4 +40,21 @@ describe('axe.utils.findBy', function () {
   it('should not throw if passed falsey first parameter', function () {
     assert.isUndefined(axe.utils.findBy(null, 'id', 'macaque'));
   });
+
+  it('ignores any non-object elements in the array', function () {
+    const obj = {
+      id: 'monkeys',
+      foo: 'bar'
+    };
+    const array = ['bananas', true, null, 123, obj];
+
+    assert.equal(axe.utils.findBy(array, 'id', 'monkeys'), obj);
+  });
+
+  it('only looks at owned properties', function () {
+    const obj1 = { id: 'monkeys', eat: 'bananas' };
+    const obj2 = Object.create(obj1);
+    obj2.id = 'gorillas';
+    assert.equal(axe.utils.findBy([obj2, obj1], 'eat', 'bananas'), obj1);
+  });
 });

test/core/utils/selector-cache.js

@@ -55,6 +55,29 @@ describe('utils.selector-cache', function () {
 
       assert.lengthOf(Object.keys(map), 0);
     });
+
+    describe('with javascripty attribute selectors', function () {
+      const terms = [
+        'prototype',
+        'constructor',
+        '__proto__',
+        'Element',
+        'nodeName',
+        'valueOf',
+        'toString'
+      ];
+      for (const term of terms) {
+        it(`works with ${term}`, function () {
+          fixture.innerHTML = `<div id="${term}" class="${term}" aria-label="${term}"></div>`;
+          const vNode = new axe.VirtualNode(fixture.firstChild);
+          const map = {};
+          cacheNodeSelectors(vNode, map);
+          assert.deepEqual(map['[id]'], [vNode]);
+          assert.deepEqual(map['[class]'], [vNode]);
+          assert.deepEqual(map['[aria-label]'], [vNode]);
+        });
+      }
+    });
   });
 
   describe('getNodesMatchingExpression', function () {

test/integration/full/all-rules/all-rules.html

@@ -28,11 +28,11 @@
       >
       <banner></banner>
       <main>
-        <div accesskey="B"></div>
+        <div accesskey="B" id="__proto__"></div>
         <map>
           <area href="#" id="pass1" alt="monkeys" />
         </map>
-        <div aria-label="foo">Foo</div>
+        <div aria-label="foo" id="constructor">Foo</div>
         <div role="contentinfo"></div>
         <div role="link">Home</div>
         <div role="dialog" aria-label="Cookies"></div>
@@ -51,7 +51,7 @@
           <div role="treeitem">Item</div>
         </div>
         <audio id="caption"><track kind="captions" /></audio>
-        <input autocomplete="username" />
+        <input autocomplete="username" id="toString" />
         <p id="fail1" style="line-height: 1.5 !important">Banana error</p>
         <p><blink>text</blink></p>
         <button id="text">Name</button>

test/integration/rules/aria-allowed-role/aria-allowed-role.html

@@ -246,7 +246,15 @@ <h1 id="pass-h1-valid-role" role="none"></h1>
 <div id="fail-dpub-4" role="doc-noteref">ok</div>
 <!-- images -->
 <div id="fail-dpub-5" role="doc-cover">ok</div>
-<img src="#" role="meter" aria-valuenow="0" aria-valuemin="0" aria-valuemax="100" alt="test" id="pass-img-valid-role-meter">
+<img
+  src="#"
+  role="meter"
+  aria-valuenow="0"
+  aria-valuemin="0"
+  aria-valuemax="100"
+  alt="test"
+  id="pass-img-valid-role-meter"
+/>
 <img role="doc-cover" aria-label="foo" id="pass-img-valid-role-aria-label" />
 <img role="menuitem" title="bar" id="pass-img-valid-role-title" />
 <div id="image-baz">hazaar</div>