imported shadowMutations from ally.js

inject.js

@@ -449,6 +449,215 @@
       if (document.querySelector('apple-tv-plus-player')) {
         console.log('Congratulations. There is the apple-tv-plus-player.')
       }
+
+      // start of ally.js/src/observe/shadow-mutations.js
+      // import nodeArray from '../util/node-array';
+        // input may be undefined, selector-tring, Node, NodeList, HTMLCollection, array of Nodes
+        // yes, to some extent this is a bad replica of jQuery's constructor function
+        function nodeArray(input) {
+          if (!input) {
+            return [];
+          }
+
+          if (Array.isArray(input)) {
+            return input;
+          }
+
+          // instanceof Node - does not work with iframes
+          if (input.nodeType !== undefined) {
+            return [input];
+          }
+
+          if (typeof input === 'string') {
+            input = document.querySelectorAll(input);
+          }
+
+          if (input.length !== undefined) {
+            return [].slice.call(input, 0);
+          }
+
+          throw new TypeError('unexpected input ' + String(input));
+        }
+      //import queryShadowHosts from '../query/shadow-hosts';
+        //import contextToElement from '../util/context-to-element';
+          //import nodeArray from '../util/node-array'; already imported
+
+        function contextToElement({
+          context,
+          label = 'context-to-element',
+          resolveDocument,
+          defaultToDocument,
+        }) {
+          let element = nodeArray(context)[0];
+
+          if (resolveDocument && element && element.nodeType === Node.DOCUMENT_NODE) {
+            element = element.documentElement;
+          }
+
+          if (!element && defaultToDocument) {
+            return document.documentElement;
+          }
+
+          if (!element) {
+            throw new TypeError(label + ' requires valid options.context');
+          }
+
+          if (element.nodeType !== Node.ELEMENT_NODE && element.nodeType !== Node.DOCUMENT_FRAGMENT_NODE) {
+            throw new TypeError(label + ' requires options.context to be an Element');
+          }
+
+          return element;
+        }
+          //import getDocument from '../util/get-document';
+          function getDocument(node) {
+          if (!node) {
+            return document;
+          }
+
+          if (node.nodeType === Node.DOCUMENT_NODE) {
+            return node;
+          }
+
+          return node.ownerDocument || document;
+        }
+
+        // see https://developer.mozilla.org/en-US/docs/Web/API/NodeFilter
+        const filter = function(node) {
+        if (node.shadowRoot) {
+          return NodeFilter.FILTER_ACCEPT;
+        }
+
+        return NodeFilter.FILTER_SKIP;
+        };
+        // IE requires a function, Browsers require {acceptNode: function}
+        // see http://www.bennadel.com/blog/2607-finding-html-comment-nodes-in-the-dom-using-treewalker.htm
+        filter.acceptNode = filter;
+
+        function queryShadowHosts({ context } = {}) {
+        const element = contextToElement({
+          label: 'query/shadow-hosts',
+          resolveDocument: true,
+          defaultToDocument: true,
+          context,
+        });
+
+        const _document = getDocument(context);
+        // see https://developer.mozilla.org/en-US/docs/Web/API/Document/createTreeWalker
+        const walker = _document.createTreeWalker(
+          // root element to start search in
+          element,
+          // element type filter
+          NodeFilter.SHOW_ELEMENT,
+          // custom NodeFilter filter
+          filter,
+          // deprecated, but IE requires it
+          false
+        );
+
+        let list = [];
+
+        if (element.shadowRoot) {
+          // TreeWalker does not run the filter on the context element
+          list.push(element);
+          list = list.concat(queryShadowHosts({
+            context: element.shadowRoot,
+          }));
+        }
+
+        while (walker.nextNode()) {
+          list.push(walker.currentNode);
+          list = list.concat(queryShadowHosts({
+            context: walker.currentNode.shadowRoot,
+          }));
+        }
+
+        return list;
+        }
+      //import contextToElement from '../util/context-to-element'; already imported
+
+      const shadowObserverConfig = {
+        childList: true,
+        subtree: true,
+      };
+
+      class ShadowMutationObserver {
+        constructor({context, callback, config} = {}) {
+          this.config = config;
+
+          this.disengage = this.disengage.bind(this);
+
+          this.clientObserver = new MutationObserver(callback);
+          this.hostObserver = new MutationObserver(mutations => mutations.forEach(this.handleHostMutation, this));
+
+          this.observeContext(context);
+          this.observeShadowHosts(context);
+        }
+
+        disengage() {
+          this.clientObserver && this.clientObserver.disconnect();
+          this.clientObserver = null;
+          this.hostObserver && this.hostObserver.disconnect();
+          this.hostObserver = null;
+        }
+
+        observeShadowHosts(context) {
+          const hosts = queryShadowHosts({
+            context,
+          });
+
+          hosts.forEach(element => this.observeContext(element.shadowRoot));
+        }
+
+        observeContext(context) {
+          this.clientObserver.observe(context, this.config);
+          this.hostObserver.observe(context, shadowObserverConfig);
+        }
+
+        handleHostMutation(mutation) {
+          if (mutation.type !== 'childList') {
+            return;
+          }
+
+          const addedElements = nodeArray(mutation.addedNodes).filter(element => element.nodeType === Node.ELEMENT_NODE);
+          addedElements.forEach(this.observeShadowHosts, this);
+        }
+      }
+
+      function shadowMutations(context, callback, config) {
+        if (typeof callback !== 'function') {
+          throw new TypeError('observe/shadow-mutations requires options.callback to be a function');
+        }
+
+        if (typeof config !== 'object') {
+          throw new TypeError('observe/shadow-mutations requires options.config to be an object');
+        }
+
+        if (!window.MutationObserver) {
+          // not supporting IE10 via Mutation Events, because they're too expensive
+          // https://developer.mozilla.org/en-US/docs/Web/Guide/Events/Mutation_events
+          return {
+            disengage: function() {},
+          };
+        }
+
+        const element = contextToElement({
+          label: 'observe/shadow-mutations',
+          resolveDocument: true,
+          defaultToDocument: true,
+          context,
+        });
+
+        const service = new ShadowMutationObserver({
+          context: element,
+          callback,
+          config,
+        });
+
+        return {
+          disengage: service.disengage,
+        };
+      }
+      //end of ally.js/src/observe/shadow-mutations.js
   }
 
   function runAction(action, document, value, e) {