✨ [POC] Track actions in shadow dom

packages/rum-core/src/browser/htmlDomUtils.ts

@@ -43,3 +43,19 @@ export function forEachChildNodes(node: Node, callback: (child: Node) => void) {
 export function getParentNode(node: Node): Node | null {
   return isNodeShadowRoot(node) ? node.host : node.parentNode
 }
+
+/**
+ * Return the parent element, crossing shadow DOM boundaries.
+ * If the element is a direct child of a shadow root, returns the shadow host.
+ */
+export function getParentElement(element: Element): Element | null {
+  if (element.parentElement) {
+    return element.parentElement
+  }
+  // If parentElement is null, check if we're in a shadow root
+  const parentNode = element.parentNode
+  if (parentNode && isNodeShadowRoot(parentNode)) {
+    return parentNode.host
+  }
+  return null
+}

packages/rum-core/src/domain/action/getActionNameFromElement.spec.ts

@@ -930,4 +930,123 @@ describe('getActionNameFromElement', () => {
       })
     })
   })
+
+  describe('shadow DOM support', () => {
+    it('extracts text content from element inside shadow DOM', () => {
+      const host = appendElement('<div></div>')
+      const shadowRoot = host.attachShadow({ mode: 'open' })
+      const button = document.createElement('button')
+      button.textContent = 'Shadow Button'
+      shadowRoot.appendChild(button)
+
+      const { name, nameSource } = getActionNameFromElement(button, defaultConfiguration)
+      expect(name).toBe('Shadow Button')
+      expect(nameSource).toBe('text_content')
+    })
+
+    it('extracts aria-label from element inside shadow DOM', () => {
+      const host = appendElement('<div></div>')
+      const shadowRoot = host.attachShadow({ mode: 'open' })
+      const button = document.createElement('button')
+      button.setAttribute('aria-label', 'Accessible Label')
+      shadowRoot.appendChild(button)
+
+      const { name, nameSource } = getActionNameFromElement(button, defaultConfiguration)
+      expect(name).toBe('Accessible Label')
+      expect(nameSource).toBe('standard_attribute')
+    })
+
+    it('traverses parent elements across shadow boundary to find action name', () => {
+      const host = appendElement('<div></div>')
+      const shadowRoot = host.attachShadow({ mode: 'open' })
+      const wrapper = document.createElement('div')
+      wrapper.setAttribute('title', 'Parent Title')
+      const target = document.createElement('span')
+      wrapper.appendChild(target)
+      shadowRoot.appendChild(wrapper)
+
+      const { name, nameSource } = getActionNameFromElement(target, defaultConfiguration)
+      expect(name).toBe('Parent Title')
+      expect(nameSource).toBe('standard_attribute')
+    })
+
+    it('finds data-dd-action-name on shadow host when element is inside shadow DOM', () => {
+      const host = appendElement('<div data-dd-action-name="Custom Action"></div>')
+      const shadowRoot = host.attachShadow({ mode: 'open' })
+      const target = document.createElement('button')
+      shadowRoot.appendChild(target)
+
+      const { name, nameSource } = getActionNameFromElement(target, defaultConfiguration)
+      expect(name).toBe('Custom Action')
+      expect(nameSource).toBe('custom_attribute')
+    })
+
+    it('finds data-dd-action-name on ancestor outside shadow DOM', () => {
+      const ancestor = appendElement('<div data-dd-action-name="Ancestor Action"><div id="host"></div></div>')
+      const host = ancestor.querySelector('#host')!
+      const shadowRoot = host.attachShadow({ mode: 'open' })
+      const target = document.createElement('button')
+      shadowRoot.appendChild(target)
+
+      const { name, nameSource } = getActionNameFromElement(target, defaultConfiguration)
+      expect(name).toBe('Ancestor Action')
+      expect(nameSource).toBe('custom_attribute')
+    })
+
+    it('prefers data-dd-action-name closer to the element inside shadow DOM', () => {
+      const host = appendElement('<div data-dd-action-name="Host Action"></div>')
+      const shadowRoot = host.attachShadow({ mode: 'open' })
+      const wrapper = document.createElement('div')
+      wrapper.setAttribute('data-dd-action-name', 'Inner Action')
+      const target = document.createElement('button')
+      wrapper.appendChild(target)
+      shadowRoot.appendChild(wrapper)
+
+      const { name, nameSource } = getActionNameFromElement(target, defaultConfiguration)
+      expect(name).toBe('Inner Action')
+      expect(nameSource).toBe('custom_attribute')
+    })
+
+    it('handles nested shadow DOMs', () => {
+      const outerHost = appendElement('<div data-dd-action-name="Outer Action"></div>')
+      const outerShadowRoot = outerHost.attachShadow({ mode: 'open' })
+
+      const innerHost = document.createElement('div')
+      outerShadowRoot.appendChild(innerHost)
+      const innerShadowRoot = innerHost.attachShadow({ mode: 'open' })
+
+      const target = document.createElement('button')
+      innerShadowRoot.appendChild(target)
+
+      const { name, nameSource } = getActionNameFromElement(target, defaultConfiguration)
+      expect(name).toBe('Outer Action')
+      expect(nameSource).toBe('custom_attribute')
+    })
+
+    it('gets parent textual content from shadow host when element has no name', () => {
+      const wrapper = appendElement('<div><div id="host-container"></div></div>')
+      const host = wrapper.querySelector('#host-container')!
+      host.setAttribute('title', 'Host Title')
+      const shadowRoot = host.attachShadow({ mode: 'open' })
+      const target = document.createElement('span')
+      shadowRoot.appendChild(target)
+
+      const { name, nameSource } = getActionNameFromElement(target, defaultConfiguration)
+      expect(name).toBe('Host Title')
+      expect(nameSource).toBe('standard_attribute')
+    })
+
+    it('respects FORM boundary inside shadow DOM', () => {
+      const host = appendElement('<div title="Host Title"></div>')
+      const shadowRoot = host.attachShadow({ mode: 'open' })
+      const form = document.createElement('form')
+      const target = document.createElement('span')
+      form.appendChild(target)
+      shadowRoot.appendChild(form)
+
+      const { name, nameSource } = getActionNameFromElement(target, defaultConfiguration)
+      expect(name).toBe('')
+      expect(nameSource).toBe('blank')
+    })
+  })
 })

packages/rum-core/src/domain/action/getActionNameFromElement.ts

@@ -3,7 +3,7 @@ import { getPrivacySelector, NodePrivacyLevel } from '../privacyConstants'
 import { getNodePrivacyLevel, maskDisallowedTextContent, shouldMaskNode, shouldMaskAttribute } from '../privacy'
 import type { NodePrivacyLevelCache } from '../privacy'
 import type { RumConfiguration } from '../configuration'
-import { isElementNode } from '../../browser/htmlDomUtils'
+import { isElementNode, getParentElement } from '../../browser/htmlDomUtils'
 import {
   ActionNameSource,
   DEFAULT_PROGRAMMATIC_ACTION_NAME_ATTRIBUTE,
@@ -49,7 +49,8 @@ export function getActionNameFromElement(
 function getActionNameFromElementProgrammatically(targetElement: Element, programmaticAttribute: string) {
   // We don't use getActionNameFromElementForStrategies here, because we want to consider all parents,
   // without limit. It is up to the user to declare a relevant naming strategy.
-  const elementWithAttribute = targetElement.closest(`[${programmaticAttribute}]`)
+  // Use shadow-aware closest to cross shadow DOM boundaries
+  const elementWithAttribute = closestShadowAware(targetElement, `[${programmaticAttribute}]`)
 
   if (!elementWithAttribute) {
     return
@@ -58,6 +59,17 @@ function getActionNameFromElementProgrammatically(targetElement: Element, progra
   return truncate(normalizeWhitespace(name.trim()))
 }
 
+function closestShadowAware(element: Element, selector: string): Element | null {
+  let current: Element | null = element
+  while (current) {
+    if (current.matches(selector)) {
+      return current
+    }
+    current = getParentElement(current)
+  }
+  return null
+}
+
 type NameStrategy = (
   element: Element | HTMLElement | HTMLInputElement | HTMLSelectElement,
   rumConfiguration: RumConfiguration,
@@ -128,6 +140,7 @@ const fallbackStrategies: NameStrategy[] = [
 /**
  * Iterates over the target element and its parent, using the strategies list to get an action name.
  * Each strategies are applied on each element, stopping as soon as a non-empty value is returned.
+ * Uses shadow-aware parent traversal to cross shadow DOM boundaries.
  */
 const MAX_PARENTS_TO_CONSIDER = 10
 function getActionNameFromElementForStrategies(
@@ -160,7 +173,7 @@ function getActionNameFromElementForStrategies(
     if (element.nodeName === 'FORM') {
       break
     }
-    element = element.parentElement
+    element = getParentElement(element)
     recursionCounter += 1
   }
 }

packages/rum-core/src/domain/action/trackClickActions.ts

@@ -10,6 +10,7 @@ import {
   createValueHistory,
   PageExitReason,
 } from '@datadog/browser-core'
+import { isNodeShadowHost } from '../../browser/htmlDomUtils'
 import type { FrustrationType } from '../../rawRumEvent.types'
 import { ActionType } from '../../rawRumEvent.types'
 import type { LifeCycle } from '../lifeCycle'
@@ -143,10 +144,12 @@ function processPointerDown(
   pointerDownEvent: MouseEventOnElement,
   windowOpenObservable: Observable<void>
 ) {
+  const target = configuration.trackActionsInShadowDom ? getEventTarget(pointerDownEvent) : pointerDownEvent.target
+
   let nodePrivacyLevel: NodePrivacyLevel
 
   if (configuration.enablePrivacyForActionName) {
-    nodePrivacyLevel = getNodePrivacyLevel(pointerDownEvent.target, configuration.defaultPrivacyLevel)
+    nodePrivacyLevel = getNodePrivacyLevel(target, configuration.defaultPrivacyLevel)
   } else {
     nodePrivacyLevel = NodePrivacyLevel.ALLOW
   }
@@ -244,13 +247,18 @@ function computeClickActionBase(
   nodePrivacyLevel: NodePrivacyLevel,
   configuration: RumConfiguration
 ): ClickActionBase {
-  const rect = event.target.getBoundingClientRect()
-  const selector = getSelectorFromElement(event.target, configuration.actionNameAttribute)
+  // Get the actual target element, handling shadow DOM if enabled
+  // For composed events from shadow DOM, event.target might be the shadow host,
+  // but we want the actual element that was clicked inside the shadow root
+  const target = configuration.trackActionsInShadowDom ? getEventTarget(event) : event.target
+
+  const rect = target.getBoundingClientRect()
+  const selector = getSelectorFromElement(target, configuration.actionNameAttribute)
   if (selector) {
     updateInteractionSelector(event.timeStamp, selector)
   }
 
-  const { name, nameSource } = getActionNameFromElement(event.target, configuration, nodePrivacyLevel)
+  const { name, nameSource } = getActionNameFromElement(target, configuration, nodePrivacyLevel)
 
   return {
     type: ActionType.CLICK,
@@ -268,6 +276,15 @@ function computeClickActionBase(
     nameSource,
   }
 }
+function getEventTarget(event: MouseEventOnElement): Element {
+  if (event.composed && isNodeShadowHost(event.target) && typeof event.composedPath === 'function') {
+    const composedPath = event.composedPath()
+    if (composedPath.length > 0 && composedPath[0] instanceof Element) {
+      return composedPath[0]
+    }
+  }
+  return event.target
+}
 
 const enum ClickStatus {
   // Initial state, the click is still ongoing.

packages/rum-core/src/domain/configuration/configuration.spec.ts

@@ -612,6 +612,7 @@ describe('serializeRumConfiguration', () => {
       trackFeatureFlagsForEvents: ['vital'],
       profilingSampleRate: 42,
       propagateTraceBaggage: true,
+      trackActionsInShadowDom: true,
     }
 
     type MapRumInitConfigurationKey<Key extends string> = Key extends keyof InitConfiguration
@@ -626,7 +627,8 @@ describe('serializeRumConfiguration', () => {
         : Key extends 'trackLongTasks'
           ? 'track_long_task' // We forgot the s, keeping this for backward compatibility
           : // The following options are not reported as telemetry. Please avoid adding more of them.
-            Key extends 'applicationId' | 'subdomain'
+            // TODO: Remove trackActionsInShadowDom from this list once rum-events-format is updated
+            Key extends 'applicationId' | 'subdomain' | 'trackActionsInShadowDom'
             ? never
             : CamelToSnakeCase<Key>
     // By specifying the type here, we can ensure that serializeConfiguration is returning an

packages/rum-core/src/domain/configuration/configuration.ts

@@ -203,6 +203,15 @@ export interface RumInitConfiguration extends InitConfiguration {
    */
   actionNameAttribute?: string | undefined
 
+  /**
+   * Enables tracking of user interactions within Shadow DOM elements.
+   * When enabled, click actions inside Shadow DOM will have accurate names and selectors.
+   *
+   * @category Data Collection
+   * @defaultValue false
+   */
+  trackActionsInShadowDom?: boolean | undefined
+
   // view options
   /**
    * Allows you to control RUM views creation. See [Override default RUM view names](https://docs.datadoghq.com/real_user_monitoring/browser/advanced_configuration/?tab=npm#override-default-rum-view-names) for further information.
@@ -286,6 +295,7 @@ export interface GraphQlUrlOption {
 export interface RumConfiguration extends Configuration {
   // Built from init configuration
   actionNameAttribute: string | undefined
+  trackActionsInShadowDom: boolean
   traceSampleRate: number
   rulePsr: number | undefined
   allowedTracingUrls: TracingOption[]
@@ -358,6 +368,7 @@ export function validateAndBuildRumConfiguration(
   return {
     applicationId: initConfiguration.applicationId,
     actionNameAttribute: initConfiguration.actionNameAttribute,
+    trackActionsInShadowDom: !!initConfiguration.trackActionsInShadowDom,
     sessionReplaySampleRate,
     startSessionReplayRecordingManually:
       initConfiguration.startSessionReplayRecordingManually !== undefined
@@ -533,6 +544,7 @@ export function serializeRumConfiguration(configuration: RumInitConfiguration) {
     remote_configuration_id: configuration.remoteConfigurationId,
     profiling_sample_rate: configuration.profilingSampleRate,
     use_remote_configuration_proxy: !!configuration.remoteConfigurationProxy,
+    // TODO: Add track_actions_in_shadow_dom once rum-events-format is updated
     ...baseSerializedConfiguration,
   } satisfies RawTelemetryConfiguration
 }