fix duplicated shadow dom (#1095)

* fix: duplicated elements in shadow doms

clean observers before taking new full snapshots

* add checker for replayer to make it stable when data has duplicated nodes

* apply review suggestions

* add change log

* Apply formatting changes

* update prettier to fit the master branch

---------

Co-authored-by: Mark-Fenng <Mark-Fenng@users.noreply.github.com>

.changeset/loud-seals-raise.md

@@ -0,0 +1,6 @@
+---
+'rrweb-snapshot': patch
+'rrweb': patch
+---
+
+Fix duplicated shadow doms

package.json

@@ -32,6 +32,7 @@
     "lerna": "^4.0.0",
     "markdownlint": "^0.25.1",
     "markdownlint-cli": "^0.31.1",
+    "prettier": "2.8.4",
     "turbo": "^1.2.4",
     "typescript": "^4.7.3"
   },

packages/rrweb-snapshot/src/rebuild.ts

@@ -8,7 +8,7 @@ import {
   attributes,
   legacyAttributes,
 } from './types';
-import { isElement, Mirror } from './utils';
+import { isElement, Mirror, isNodeMetaEqual } from './utils';
 
 const tagMap: tagMap = {
   script: 'noscript',
@@ -364,6 +364,19 @@ export function buildNodeWithSN(
     afterAppend,
     cache,
   } = options;
+  /**
+   * Add a check to see if the node is already in the mirror. If it is, we can skip the whole process.
+   * This situation (duplicated nodes) can happen when recorder has some unfixed bugs and the same node is recorded twice. Or something goes wrong when saving or transferring event data.
+   * Duplicated node creation may cause unexpected errors in replayer. This check tries best effort to prevent the errors.
+   */
+  if (mirror.has(n.id)) {
+    // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+    const nodeInMirror = mirror.getNode(n.id)!;
+    // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+    const meta = mirror.getMeta(nodeInMirror)!;
+    // For safety concern, check if the node in mirror is the same as the node we are trying to build
+    if (isNodeMetaEqual(meta, n)) return mirror.getNode(n.id);
+  }
   let node = buildNode(n, { doc, hackCss, cache });
   if (!node) {
     return null;

packages/rrweb-snapshot/src/utils.ts

@@ -5,6 +5,12 @@ import {
   nodeMetaMap,
   IMirror,
   serializedNodeWithId,
+  serializedNode,
+  NodeType,
+  documentNode,
+  documentTypeNode,
+  textNode,
+  elementNode,
 } from './types';
 
 export function isElement(n: Node): n is Element {
@@ -213,3 +219,30 @@ export function is2DCanvasBlank(canvas: HTMLCanvasElement): boolean {
   }
   return true;
 }
+
+export function isNodeMetaEqual(a: serializedNode, b: serializedNode): boolean {
+  if (!a || !b || a.type !== b.type) return false;
+  if (a.type === NodeType.Document)
+    return a.compatMode === (b as documentNode).compatMode;
+  else if (a.type === NodeType.DocumentType)
+    return (
+      a.name === (b as documentTypeNode).name &&
+      a.publicId === (b as documentTypeNode).publicId &&
+      a.systemId === (b as documentTypeNode).systemId
+    );
+  else if (
+    a.type === NodeType.Comment ||
+    a.type === NodeType.Text ||
+    a.type === NodeType.CDATA
+  )
+    return a.textContent === (b as textNode).textContent;
+  else if (a.type === NodeType.Element)
+    return (
+      a.tagName === (b as elementNode).tagName &&
+      JSON.stringify(a.attributes) ===
+        JSON.stringify((b as elementNode).attributes) &&
+      a.isSVG === (b as elementNode).isSVG &&
+      a.needBlock === (b as elementNode).needBlock
+    );
+  return false;
+}

packages/rrweb-snapshot/test/utils.test.ts

@@ -0,0 +1,150 @@
+/**
+ * @jest-environment jsdom
+ */
+import { NodeType, serializedNode } from '../src/types';
+import { isNodeMetaEqual } from '../src/utils';
+import { serializedNodeWithId } from 'rrweb-snapshot';
+
+describe('utils', () => {
+  describe('isNodeMetaEqual()', () => {
+    const document1: serializedNode = {
+      type: NodeType.Document,
+      compatMode: 'CSS1Compat',
+      childNodes: [],
+    };
+    const document2: serializedNode = {
+      type: NodeType.Document,
+      compatMode: 'BackCompat',
+      childNodes: [],
+    };
+    const documentType1: serializedNode = {
+      type: NodeType.DocumentType,
+      name: 'html',
+      publicId: '',
+      systemId: '',
+    };
+    const documentType2: serializedNode = {
+      type: NodeType.DocumentType,
+      name: 'html',
+      publicId: '',
+      systemId: 'http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd',
+    };
+    const text1: serializedNode = {
+      type: NodeType.Text,
+      textContent: 'Hello World',
+    };
+    const text2: serializedNode = {
+      type: NodeType.Text,
+      textContent: 'Hello world',
+    };
+    const comment1: serializedNode = {
+      type: NodeType.Comment,
+      textContent: 'Hello World',
+    };
+    const comment2: serializedNode = {
+      type: NodeType.Comment,
+      textContent: 'Hello world',
+    };
+    const element1: serializedNode = {
+      type: NodeType.Element,
+      tagName: 'div',
+      attributes: {
+        className: 'test',
+      },
+      childNodes: [],
+    };
+    const element2: serializedNode = {
+      type: NodeType.Element,
+      tagName: 'span',
+      attributes: {
+        'aria-label': 'Hello World',
+      },
+      childNodes: [],
+    };
+    const element3: serializedNode = {
+      type: NodeType.Element,
+      tagName: 'div',
+      attributes: { id: 'test' },
+      childNodes: [comment1 as serializedNodeWithId],
+    };
+
+    it('should return false if two nodes have different node types', () => {
+      expect(
+        isNodeMetaEqual(
+          undefined as unknown as serializedNode,
+          null as unknown as serializedNode,
+        ),
+      ).toBeFalsy();
+      expect(isNodeMetaEqual(document1, element1)).toBeFalsy();
+      expect(isNodeMetaEqual(document1, documentType1)).toBeFalsy();
+      expect(isNodeMetaEqual(documentType1, element1)).toBeFalsy();
+      expect(isNodeMetaEqual(text1, comment1)).toBeFalsy();
+      expect(isNodeMetaEqual(text1, element1)).toBeFalsy();
+      expect(isNodeMetaEqual(comment1, element1)).toBeFalsy();
+    });
+
+    it('should compare meta data of two document nodes', () => {
+      expect(
+        isNodeMetaEqual(document1, JSON.parse(JSON.stringify(document1))),
+      ).toBeTruthy();
+      expect(
+        isNodeMetaEqual(JSON.parse(JSON.stringify(document2)), document2),
+      ).toBeTruthy();
+      expect(isNodeMetaEqual(document1, document2)).toBeFalsy();
+    });
+
+    it('should compare meta data of two documentType nodes', () => {
+      expect(
+        isNodeMetaEqual(
+          documentType1,
+          JSON.parse(JSON.stringify(documentType1)),
+        ),
+      ).toBeTruthy();
+      expect(
+        isNodeMetaEqual(
+          JSON.parse(JSON.stringify(documentType2)),
+          documentType2,
+        ),
+      ).toBeTruthy();
+      expect(isNodeMetaEqual(documentType1, documentType2)).toBeFalsy();
+    });
+
+    it('should compare meta data of two text nodes', () => {
+      expect(
+        isNodeMetaEqual(text1, JSON.parse(JSON.stringify(text1))),
+      ).toBeTruthy();
+      expect(
+        isNodeMetaEqual(JSON.parse(JSON.stringify(text2)), text2),
+      ).toBeTruthy();
+      expect(isNodeMetaEqual(text1, text2)).toBeFalsy();
+    });
+
+    it('should compare meta data of two comment nodes', () => {
+      expect(
+        isNodeMetaEqual(comment1, JSON.parse(JSON.stringify(comment1))),
+      ).toBeTruthy();
+      expect(
+        isNodeMetaEqual(JSON.parse(JSON.stringify(comment2)), comment2),
+      ).toBeTruthy();
+      expect(isNodeMetaEqual(comment1, comment2)).toBeFalsy();
+    });
+
+    it('should compare meta data of two HTML elements', () => {
+      expect(
+        isNodeMetaEqual(element1, JSON.parse(JSON.stringify(element1))),
+      ).toBeTruthy();
+      expect(
+        isNodeMetaEqual(JSON.parse(JSON.stringify(element2)), element2),
+      ).toBeTruthy();
+      expect(
+        isNodeMetaEqual(element1, {
+          ...element1,
+          childNodes: [comment2 as serializedNodeWithId],
+        }),
+      ).toBeTruthy();
+      expect(isNodeMetaEqual(element1, element2)).toBeFalsy();
+      expect(isNodeMetaEqual(element1, element3)).toBeFalsy();
+      expect(isNodeMetaEqual(element2, element3)).toBeFalsy();
+    });
+  });
+});

packages/rrweb/package.json

@@ -53,7 +53,6 @@
     "@types/jest-image-snapshot": "^5.1.0",
     "@types/node": "^17.0.21",
     "@types/offscreencanvas": "^2019.6.4",
-    "@types/prettier": "^2.3.2",
     "@types/puppeteer": "^5.4.4",
     "construct-style-sheets-polyfill": "^3.1.0",
     "cross-env": "^5.2.0",
@@ -65,7 +64,6 @@
     "jest": "^27.5.1",
     "jest-image-snapshot": "^5.2.0",
     "jest-snapshot": "^23.6.0",
-    "prettier": "2.2.1",
     "puppeteer": "^11.0.0",
     "rollup": "^2.68.0",
     "rollup-plugin-esbuild": "^4.9.1",

packages/rrweb/src/record/index.ts

@@ -348,8 +348,8 @@ function record<T = eventWithTime>(
 
     // When we take a full snapshot, old tracked StyleSheets need to be removed.
     stylesheetManager.reset();
-    // Old shadow doms cache need to be cleared.
+
-    shadowDomManager.clearCache();
+    shadowDomManager.init();
 
     mutationBuffers.forEach((buf) => buf.lock()); // don't allow any mirror modifications during snapshotting
     const node = snapshot(document, {

packages/rrweb/src/record/shadow-dom-manager.ts

@@ -26,7 +26,7 @@ export class ShadowDomManager {
   private scrollCb: scrollCallback;
   private bypassOptions: BypassOptions;
   private mirror: Mirror;
-  private restorePatches: (() => void)[] = [];
+  private restoreHandlers: (() => void)[] = [];
 
   constructor(options: {
     mutationCb: mutationCallBack;
@@ -39,34 +39,20 @@ export class ShadowDomManager {
     this.bypassOptions = options.bypassOptions;
     this.mirror = options.mirror;
 
-    // Patch 'attachShadow' to observe newly added shadow doms.
+    this.init();
-    // eslint-disable-next-line @typescript-eslint/no-this-alias
+  }
-    const manager = this;
-    this.restorePatches.push(
-      patch(
-        Element.prototype,
-        'attachShadow',
-        function (original: (init: ShadowRootInit) => ShadowRoot) {
-          return function (this: HTMLElement, option: ShadowRootInit) {
-            const shadowRoot = original.call(this, option);
 
-            // For the shadow dom elements in the document, monitor their dom mutations.
+  public init() {
-            // For shadow dom elements that aren't in the document yet,
+    this.reset();
-            // we start monitoring them once their shadow dom host is appended to the document.
+    // Patch 'attachShadow' to observe newly added shadow doms.
-            if (this.shadowRoot && inDom(this))
+    this.patchAttachShadow(Element, document);
-              manager.addShadowRoot(this.shadowRoot, this.ownerDocument);
-            return shadowRoot;
-          };
-        },
-      ),
-    );
   }
 
   public addShadowRoot(shadowRoot: ShadowRoot, doc: Document) {
     if (!isNativeShadowDom(shadowRoot)) return;
     if (this.shadowDoms.has(shadowRoot)) return;
     this.shadowDoms.add(shadowRoot);
-    initMutationObserver(
+    const observer = initMutationObserver(
       {
         ...this.bypassOptions,
         doc,
@@ -76,14 +62,17 @@ export class ShadowDomManager {
       },
       shadowRoot,
     );
-    initScrollObserver({
+    this.restoreHandlers.push(() => observer.disconnect());
-      ...this.bypassOptions,
+    this.restoreHandlers.push(
-      scrollCb: this.scrollCb,
+      initScrollObserver({
-      // https://gist.github.com/praveenpuglia/0832da687ed5a5d7a0907046c9ef1813
+        ...this.bypassOptions,
-      // scroll is not allowed to pass the boundary, so we need to listen the shadow document
+        scrollCb: this.scrollCb,
-      doc: shadowRoot as unknown as Document,
+        // https://gist.github.com/praveenpuglia/0832da687ed5a5d7a0907046c9ef1813
-      mirror: this.mirror,
+        // scroll is not allowed to pass the boundary, so we need to listen the shadow document
-    });
+        doc: shadowRoot as unknown as Document,
+        mirror: this.mirror,
+      }),
+    );
     // Defer this to avoid adoptedStyleSheet events being created before the full snapshot is created or attachShadow action is recorded.
     setTimeout(() => {
       if (
@@ -94,12 +83,14 @@ export class ShadowDomManager {
           shadowRoot.adoptedStyleSheets,
           this.mirror.getId(shadowRoot.host),
         );
-      initAdoptedStyleSheetObserver(
+      this.restoreHandlers.push(
-        {
+        initAdoptedStyleSheetObserver(
-          mirror: this.mirror,
+          {
-          stylesheetManager: this.bypassOptions.stylesheetManager,
+            mirror: this.mirror,
-        },
+            stylesheetManager: this.bypassOptions.stylesheetManager,
-        shadowRoot,
+          },
+          shadowRoot,
+        ),
       );
     }, 0);
   }
@@ -108,39 +99,57 @@ export class ShadowDomManager {
    * Monkey patch 'attachShadow' of an IFrameElement to observe newly added shadow doms.
    */
   public observeAttachShadow(iframeElement: HTMLIFrameElement) {
-    if (iframeElement.contentWindow) {
+    if (!iframeElement.contentWindow || !iframeElement.contentDocument) return;
-      // eslint-disable-next-line @typescript-eslint/no-this-alias
+
-      const manager = this;
+    this.patchAttachShadow(
-      this.restorePatches.push(
+      (
-        patch(
+        iframeElement.contentWindow as Window & {
-          (
+          Element: { prototype: Element };
-            iframeElement.contentWindow as Window & {
+        }
-              HTMLElement: { prototype: HTMLElement };
+      ).Element,
-            }
+      iframeElement.contentDocument,
-          ).HTMLElement.prototype,
+    );
-          'attachShadow',
-          function (original: (init: ShadowRootInit) => ShadowRoot) {
-            return function (this: HTMLElement, option: ShadowRootInit) {
-              const shadowRoot = original.call(this, option);
-              if (this.shadowRoot)
-                manager.addShadowRoot(
-                  this.shadowRoot,
-                  iframeElement.contentDocument as Document,
-                );
-              return shadowRoot;
-            };
-          },
-        ),
-      );
-    }
   }
 
-  public clearCache() {
+  /**
-    this.shadowDoms = new WeakSet();
+   * Patch 'attachShadow' to observe newly added shadow doms.
+   */
+  private patchAttachShadow(
+    element: {
+      prototype: Element;
+    },
+    doc: Document,
+  ) {
+    // eslint-disable-next-line @typescript-eslint/no-this-alias
+    const manager = this;
+    this.restoreHandlers.push(
+      patch(
+        element.prototype,
+        'attachShadow',
+        function (original: (init: ShadowRootInit) => ShadowRoot) {
+          return function (this: Element, option: ShadowRootInit) {
+            const shadowRoot = original.call(this, option);
+            // For the shadow dom elements in the document, monitor their dom mutations.
+            // For shadow dom elements that aren't in the document yet,
+            // we start monitoring them once their shadow dom host is appended to the document.
+            if (this.shadowRoot && inDom(this))
+              manager.addShadowRoot(this.shadowRoot, doc);
+            return shadowRoot;
+          };
+        },
+      ),
+    );
   }
 
   public reset() {
-    this.restorePatches.forEach((restorePatch) => restorePatch());
+    this.restoreHandlers.forEach((handler) => {
-    this.clearCache();
+      try {
+        handler();
+      } catch (e) {
+        //
+      }
+    });
+    this.restoreHandlers = [];
+    this.shadowDoms = new WeakSet();
   }
 }

yarn.lock

@@ -2547,11 +2547,6 @@
   resolved "https://registry.npmjs.org/@types/prettier/-/prettier-2.4.1.tgz"
   integrity sha512-Fo79ojj3vdEZOHg3wR9ksAMRz4P3S5fDB5e/YWZiFnyFQI1WY2Vftu9XoXVVtJfxB7Bpce/QTqWSSntkz2Znrw==
 
-"@types/prettier@^2.3.2":
-  version "2.3.2"
-  resolved "https://registry.npmjs.org/@types/prettier/-/prettier-2.3.2.tgz"
-  integrity sha512-eI5Yrz3Qv4KPUa/nSIAi0h+qX0XyewOliug5F2QAtuRg6Kjg6jfmxe1GIwoIRhZspD1A0RP8ANrPwvEXXtRFog==
-
 "@types/pug@^2.0.4":
   version "2.0.5"
   resolved "https://registry.npmjs.org/@types/pug/-/pug-2.0.5.tgz"
@@ -10445,12 +10440,7 @@ preserve@^0.2.0:
   resolved "https://registry.npmjs.org/preserve/-/preserve-0.2.0.tgz"
   integrity sha1-gV7R9uvGWSb4ZbMQwHE7yzMVzks=
 
-prettier@2.2.1:
+prettier@2.8.4, prettier@^2.7.1:
-  version "2.2.1"
-  resolved "https://registry.npmjs.org/prettier/-/prettier-2.2.1.tgz"
-  integrity sha512-PqyhM2yCjg/oKkFPtTGUojv7gnZAoG80ttl45O6x2Ug/rMJw4wcc9k6aaf2hibP7BGVCCM33gZoGjyvt9mm16Q==
-
-prettier@^2.7.1:
   version "2.8.4"
   resolved "https://registry.yarnpkg.com/prettier/-/prettier-2.8.4.tgz#34dd2595629bfbb79d344ac4a91ff948694463c3"
   integrity sha512-vIS4Rlc2FNh0BySk3Wkd6xmwxB0FpOndW5fisM5H8hsZSxU2VWVB5CWIkIjWvrHjIhxk2g3bfMKM87zNTrZddw==