WebDriver BiDi for SeleniumVBA

May 31, 2026 · View on GitHub

【5/31/2026 Updated] Improved robustness for SPA environments.

I have uploaded an experimental file that shows WebDriver BiDi working with SeleniumVBA (@GCuser99). To prevent the file from being deleted due to a false positive by Windows Defender, a password "123" is set for the file.

This VBA program was developed based on "ZeroInstall BrowserDriver for VBA" (@kabkabkab) and changed the connection from CDP to WebDriver BiDi with a WebSocket communication. I created this in hopes of making it possible to detect Events using SeleniumVBA (@GCuser99).

To overcome the flakiness arising from DOM updates and async requests in modern SPAs like React and Vue.js, I’m challenging the boundaries of what’s possible with VBA.Since we assume the concurrent use of both Classic and BiDi, the BiDi methods are kept to a minimum.

For validation purposes, I have established a challenging benchmark: correctly entering text into the ServiceNow login form. ServiceNow is frequently cited as one of the most difficult Single Page Applications (SPAs) to automate. The execution code is contained in the Main07 procedure.

[Supported OS]

  • Windows11

[Supported Browsers]

  • Edge / Chrome
  • Firefox is not supported due to functional limitations.

📂 Procedure Overview (Sample Module: A_01_BiDi_Sample)

1. Main01: Enhanced Select Box & Extension Injection & Recording

This procedure focuses on handling elements that trigger complex JavaScript state changes.

  • Dynamic Extension Injection: Utilizes the WebDriver BiDi ExecuteWebExtensionInstall command to load extensions directly into the browser session from a local path. This enables the runtime "bypass injection" of extensions without cluttering the system registry. (Note: Please ensure that the Google Translate Chrome extension is installed on your PC in advance.)
  • Smart Selection: Utilizes ExecuteSelectValueByXPath. This command can be configured to wait for the browser's "Idle" state immediately after selection, ensuring subsequent UI updates are fully rendered before proceeding.

2. Main02: Auto-Scrolling for Lazy Load & Dynamic SPA Synchronization

Designed for Single-Page Application (SPA) environments that utilize infinite scrolling (lazy loading) like note.com, this procedure ensures reliable interaction with elements dynamically added to the DOM.

  • Inducing Dynamic Loads via Auto-Scrolling: By using the ExecuteLazyLoadScroll method, the script repeatedly scrolls to the bottom of the page to forcefully trigger the loading of additional content (e.g., article lists).
  • Full-Stack Idleness Monitoring: After navigation and during scrolling, the script injects window.__vbaIdleProbe to monitor the browser's internal state.
  • Real-Time Traffic Tracking & Synchronization: The probe continuously tracks inflightXhrCount (active XHR requests) and inflightFetchCount (active Fetch requests). The VBA code waits for these counts to return to zero and for lastMutationTs (the timestamp of the final DOM mutation) to stabilize, guaranteeing that the dynamic feed has finished loading completely.

3. Main03: Performance Optimization via CDP-over-BiDi Bridge

This procedure demonstrates how to make automation up to 5x faster by controlling the network layer using a hybrid protocol approach.

  • Hybrid Protocol Bridge: Utilizes ExecuteEnableResourceBlocking to filter out heavy resources like images, ad scripts, and tracking beacons before navigation.
  • Post-Navigation Idleness Probe: Injects window.__vbaIdleProbe to ensure the environment is quiescent before entering data, maximizing execution speed and reliability.

4. Main04: Event-Driven URL Monitoring

Bypasses the "flaky" nature of login redirections by moving away from polling.

  • Event vs. Polling: Uses ExecuteIsUrlContains to hook into the browser's internal navigation events. The script wakes up instantly the millisecond the URL matches the target, ensuring no time is wasted waiting for fixed intervals.

5. Main05: Asynchronous DOM Mutation & State Validation

Focuses on synchronizing with elements that are delayed or generated via AJAX, ensuring the script does not outpace the UI updates.

  • Smart Async Interaction: Utilizes ExecuteClickByXPath to interact with AJAX-driven content. The command internally monitors BiDi events to ensure the action is processed during a stable browser state.
  • Instant State Verification: Demonstrates how to validate dynamic DOM insertions (e.g., the "Done!" label) immediately after an action, eliminating the need for manual polling loops.

6. Main06: Iframe Context Piercing & Hierarchical Mapping

Solves the "nested frame" problem found in legacy portals.

  • Context ID Retrieval: Executes GetIframeContextIdByUrl to reliably map and target deeply nested sub-frames.
  • Direct Context Targeting: Instead of using traditional context switching, the script retrieves a unique context ID for the specific frame and passes it directly into interaction commands like ExecuteClickByXPath.

7. Main07: SPA Idleness Detection & Shadow DOM Traversal

Targeting heavy JavaScript platforms (e.g., ServiceNow), this procedure implements a sophisticated "BiDi Probe" system.

  • Shadow DOM Interaction: Uses ExecuteShadowClick to pierce shadow boundaries and interact with encapsulated web components.
  • Auto-Clicker Registration: Utilizes ExecuteRegisterAutoClickerByXPath to silently and automatically handle intrusive overlays (like cookie banners) without polluting the main automation logic.

8. Main08: Heavy SPA Stress Test & Advanced Combobox Handling

Designed as a stress test targeting highly reactive SPAs (e.g., Google Flights) to manage complex React/Wiz-controlled comboboxes and heavy background network traffic.

  • Multi-Phase Input Synchronization: Implements a robust, per-character input routine (ExecuteInputValueByXPath) that waits for field activation, detects React/Wiz double DOM replacements, and safely clears values to ensure dynamic suggestion dropdowns trigger correctly.
  • Telemetry Noise Filtering: Utilizes AddIdleIgnoreNetworkPattern to continuously ignore background tracking and telemetry requests (like /log? or ogs.google.com), allowing the internal idleness probe to accurately determine when the page is truly stable.
  • Semantic ARIA Targeting: Bypasses obfuscated class names and layout shifts by relying on W3C ARIA attributes (e.g., @role='combobox', @aria-label) to reliably locate and interact with changing UI elements.

9. Main09: Discovery Log & Diagnostic Recording

A specialized tool for reverse-engineering and debugging complex automation scenarios.

  • Event Stream: Uses StartDiscoveryLog to capture a raw feed of every browser event, including network requests, console logs, and DOM changes (with an option to exclude image/css noise).
  • Analysis: Records activity using RecordEventsForSeconds for a specified duration and saves it via StopAndSaveDiscoveryLog for post-mortem analysis.

💡 Tip: By providing this log to an AI, you can identify noisy request URLs and get recommendations for the optimal idle time.

[Reference Materials]