From 1c0b9cead6d77875a25e98982f66931bc65d6e29 Mon Sep 17 00:00:00 2001
From: Tim Fish <tim@timfish.uk>
Date: Sat, 11 Jan 2025 19:26:42 +0100
Subject: [PATCH] feat(browser): Add browser View Hierarchy integration

---
 packages/browser/src/index.ts                 |   1 +
 .../src/integrations/view-hierarchy.ts        | 115 ++++++++++++++++++
 2 files changed, 116 insertions(+)
 create mode 100644 packages/browser/src/integrations/view-hierarchy.ts

diff --git a/packages/browser/src/index.ts b/packages/browser/src/index.ts
index 56c7dd449602..8d2cef356e3c 100644
--- a/packages/browser/src/index.ts
+++ b/packages/browser/src/index.ts
@@ -69,3 +69,4 @@ export {
 } from './integrations/featureFlags';
 export { launchDarklyIntegration, buildLaunchDarklyFlagUsedHandler } from './integrations/featureFlags/launchdarkly';
 export { openFeatureIntegration, OpenFeatureIntegrationHook } from './integrations/featureFlags/openfeature';
+export { viewHierarchyIntegration } from './integrations/view-hierarchy';
diff --git a/packages/browser/src/integrations/view-hierarchy.ts b/packages/browser/src/integrations/view-hierarchy.ts
new file mode 100644
index 000000000000..36ad716fdb87
--- /dev/null
+++ b/packages/browser/src/integrations/view-hierarchy.ts
@@ -0,0 +1,115 @@
+import type { Attachment, Event, ViewHierarchyData, ViewHierarchyWindow } from '@sentry/core';
+import { defineIntegration, dropUndefinedKeys, getComponentName } from '@sentry/core';
+import { WINDOW } from '../helpers';
+
+interface OnElementArgs {
+  /**
+   * The element being processed.
+   */
+  element: HTMLElement;
+  /**
+   * Lowercase tag name of the element.
+   */
+  tagName: string;
+  /**
+   * The component name of the element.
+   */
+  componentName?: string;
+}
+
+interface Options {
+  /**
+   * Whether to attach the view hierarchy to the event.
+   */
+  shouldAttach?: (event: Event) => boolean;
+
+  /**
+   * Called for each HTMLElement as we walk the DOM.
+   *
+   * Return an object to include the element with any additional properties.
+   * Return `skip` to exclude the element and its children.
+   * Return `children` to skip the element but include its children.
+   */
+  onElement?: (prop: OnElementArgs) => Record<string, string | number | boolean> | 'skip' | 'children';
+}
+
+/**
+ * An integration to include a view hierarchy attachment which contains the DOM.
+ */
+export const viewHierarchyIntegration = defineIntegration((options: Options = {}) => {
+  const skipHtmlTags = ['script'];
+
+  /** Walk an element */
+  function walk(element: { children: HTMLCollection }, windows: ViewHierarchyWindow[]): void {
+    for (const child of element.children) {
+      if (!(child instanceof HTMLElement)) {
+        continue;
+      }
+
+      const componentName = getComponentName(child) || undefined;
+      const tagName = child.tagName.toLowerCase();
+      const result = options.onElement?.({ element: child, componentName, tagName }) || {};
+
+      // Skip this element and its children
+      if (skipHtmlTags.includes(tagName) || result === 'skip') {
+        continue;
+      }
+
+      // Skip this element but include its children
+      if (result === 'children') {
+        walk('shadowRoot' in child && child.shadowRoot ? child.shadowRoot : child, windows);
+        continue;
+      }
+
+      const childRect = child.getBoundingClientRect();
+
+      const window: ViewHierarchyWindow = dropUndefinedKeys({
+        identifier: (child.id || undefined) as string,
+        type: componentName || tagName,
+        visible: true,
+        alpha: 1,
+        height: childRect.height,
+        width: childRect.width,
+        x: childRect.x,
+        y: childRect.y,
+        ...result,
+      });
+
+      const children: ViewHierarchyWindow[] = [];
+      window.children = children;
+
+      // Recursively walk the children
+      walk('shadowRoot' in child && child.shadowRoot ? child.shadowRoot : child, window.children);
+
+      windows.push(window);
+    }
+  }
+
+  return {
+    name: 'ViewHierarchy',
+    processEvent: (event, hint) => {
+      if (options.shouldAttach && options.shouldAttach(event) === false) {
+        return event;
+      }
+
+      const root: ViewHierarchyData = {
+        rendering_system: 'DOM',
+        windows: [],
+      };
+
+      walk(WINDOW.document.body, root.windows);
+
+      const attachment: Attachment = {
+        filename: 'view-hierarchy.json',
+        attachmentType: 'event.view_hierarchy',
+        contentType: 'application/json',
+        data: JSON.stringify(root),
+      };
+
+      hint.attachments = hint.attachments || [];
+      hint.attachments.push(attachment);
+
+      return event;
+    },
+  };
+});