vaev-webdriver: Intial implementation of webdriver2. #129

sleepy-monax · 2025-11-18T12:19:07Z

This rewrites the WebDriver in C++ to integrate it directly with the engine.
It now supports everything the previous implementations did. Plus PDF printing, retrieving the page source, and full session handling.

…rm support f16.

Copilot

Pull Request Overview

This PR implements a complete WebDriver 2 protocol implementation in C++ directly integrated with the Vaev engine, replacing the previous implementation. The new implementation adds support for PDF printing, page source retrieval, and full session handling.

Adds new C++ WebDriver service with HTTP endpoints for the WebDriver 2 protocol
Implements core WebDriver functionality including sessions, navigation, window management, and screen capture
Adds HTML fragment serialization support for retrieving page source

Reviewed Changes

Copilot reviewed 14 out of 14 changed files in this pull request and generated 12 comments.

Show a summary per file

File	Description
src/vaev-webdriver/service.cpp	Implements HTTP service endpoints for WebDriver 2 protocol (sessions, navigation, contexts, screenshots, printing)
src/vaev-webdriver/protocol.cpp	Defines WebDriver protocol types and helper functions for success/error responses
src/vaev-webdriver/driver.cpp	Core WebDriver logic handling sessions, windows, navigation, and document operations
src/vaev-webdriver/mod.cpp	Module exports for the WebDriver implementation
src/vaev-webdriver/manifest.json	Component manifest declaring vaev-engine dependency
src/vaev-webdriver/main/manifest.json	Executable manifest for WebDriver server
src/vaev-webdriver/main/main.cpp	Entry point for WebDriver server with CLI option parsing
src/vaev-engine/style/specified.cpp	Changes opacity field from f16 to f32 for compatibility
src/vaev-engine/style/media.cpp	Adds viewportSize() helper method to Media struct
src/vaev-engine/dom/window.cpp	Adds refreshAsync() method and refactors viewport size usage
src/vaev-engine/dom/serialisation.cpp	Implements HTML fragment serialization per WHATWG spec
src/vaev-engine/dom/names.cpp	Adds documentation comment for namespace serialization logic
src/vaev-engine/dom/mod.cpp	Exports new serialisation module
src/vaev-engine/dom/element.cpp	Adds isVoidElement() method for HTML void element detection

Copilot · 2025-11-18T12:24:39Z

src/vaev-webdriver/service.cpp

+            if (auto value = parameters.getOr("script", NONE); value.isStr()) {
+                script = value.asStr();
+            } else {
+                co_return co_await _sendErrorAsync(resp, Error::invalidInput("missing handle key"));


Error message says "missing handle key" but the actual missing key is "script". This misleading error message will confuse users when debugging.

Copilot · 2025-11-18T12:24:39Z

src/vaev-webdriver/service.cpp

+            if (auto value = parameters.getOr("script", NONE); value.isStr()) {
+                script = value.asStr();
+            } else {
+                co_return co_await _sendErrorAsync(resp, Error::invalidInput("missing handle key"));


Error message says "missing handle key" but the actual missing key is "script". This misleading error message will confuse users when debugging.

Copilot · 2025-11-18T12:24:40Z

src/vaev-webdriver/service.cpp

+            auto pageWidth = page.getOr("width", 21.59);
+
+            // Let pageHeight be the result of getting a property with default named "height" and with a default of 27.94 from page.
+            auto pageHeight = page.getOr("width", 27.94);


Copy-paste error: pageHeight is reading from "width" instead of "height". This should be page.getOr("height", 27.94) to correctly read the page height parameter.

Suggested change

auto pageHeight = page.getOr("width", 27.94);

auto pageHeight = page.getOr("height", 27.94);

Copilot · 2025-11-18T12:24:40Z

src/vaev-webdriver/protocol.cpp

+struct TimeoutConfiguration {
+    Duration script = Duration::fromMSecs(30000);
+    Duration pageLoad = Duration::fromMSecs(300000);
+    Duration implicit = Duration::fromMSecs(9);


Inconsistent default value for implicit timeout. The value is 9 milliseconds, which seems unusually low and inconsistent with the script (30 seconds) and pageLoad (5 minutes) timeouts. This should likely be 0 (no implicit wait) according to the WebDriver spec defaults.

Suggested change

Duration implicit = Duration::fromMSecs(9);

Duration implicit = Duration::fromMSecs(0); // Per WebDriver spec, default is 0ms (no implicit wait)

Copilot · 2025-11-18T12:24:40Z

src/vaev-webdriver/driver.cpp

+    // https://www.w3.org/TR/webdriver2/#get-timeouts
+    Res<> setTimeouts(Ref::Uuid sessionId, TimeoutConfiguration timeouts) {
+        auto session = try$(getSession(sessionId));
+        session->timeouts = timeouts;
+        return Ok();
+    }
+
+    // https://www.w3.org/TR/webdriver2/#set-timeouts


Comments for setTimeouts and getTimeouts are swapped. Line 79 says "https://www.w3.org/TR/webdriver2/#get-timeouts" but implements setTimeouts, while line 86 says "https://www.w3.org/TR/webdriver2/#set-timeouts" but implements getTimeouts.

Suggested change

// https://www.w3.org/TR/webdriver2/#get-timeouts

Res<> setTimeouts(Ref::Uuid sessionId, TimeoutConfiguration timeouts) {

auto session = try$(getSession(sessionId));

session->timeouts = timeouts;

return Ok();

}

// https://www.w3.org/TR/webdriver2/#set-timeouts

// https://www.w3.org/TR/webdriver2/#set-timeouts

Res<> setTimeouts(Ref::Uuid sessionId, TimeoutConfiguration timeouts) {

auto session = try$(getSession(sessionId));

session->timeouts = timeouts;

return Ok();

}

// https://www.w3.org/TR/webdriver2/#get-timeouts

Copilot · 2025-11-18T12:24:41Z

src/vaev-webdriver/service.cpp

+    // https://www.w3.org/TR/webdriver2/#resizing-and-positioning-windows
+
+    // https://www.w3.org/TR/webdriver2/#get-window-rect
+    service->post(


Incorrect HTTP method for Get Window Rect endpoint. According to the WebDriver spec (line 304 comment), this should be a GET request, not POST. The endpoint URL comment says "get-window-rect".

Suggested change

service->post(

service->get(

Copilot · 2025-11-18T12:24:42Z

src/vaev-webdriver/service.cpp

+            // Let orientation be the result of getting a property with default named "orientation" and with default "portrait" from parameters.
+            auto orientation = parameters.getOr("orientation", "portrait"s);
+            // If orientation is not a String or does not have one of the values "landscape" or "portrait", return error with error code invalid argument.
+            if (not orientation.isStr() or (orientation.asStr() != "landscape"s and orientation.asStr() != "landscape"s)) {


Typo in the orientation validation. The code checks orientation.asStr() != "landscape"s and orientation.asStr() != "landscape"s - "landscape" is checked twice instead of checking for both "landscape" and "portrait". This should be orientation.asStr() != "landscape"s and orientation.asStr() != "portrait"s.

Suggested change

if (not orientation.isStr() or (orientation.asStr() != "landscape"s and orientation.asStr() != "landscape"s)) {

if (not orientation.isStr() or (orientation.asStr() != "landscape"s and orientation.asStr() != "portrait"s)) {

Copilot · 2025-11-18T12:24:42Z

src/vaev-webdriver/service.cpp

+            // TODO
+
+            // Let margin be the result of getting a property with default named "margin" and with a default of an empty Object from parameters.
+            auto margin = parameters.getOr("page", Serde::Object{});


Copy-paste error: reading from "page" instead of "margin". This should be parameters.getOr("margin", Serde::Object{}) to correctly read the margin object from parameters.

Suggested change

auto margin = parameters.getOr("page", Serde::Object{});

auto margin = parameters.getOr("margin", Serde::Object{});

Copilot · 2025-11-18T12:24:42Z

src/vaev-webdriver/service.cpp

+        }
+    );
+
+    // https://www.w3.org/TR/webdriver2/#execute-script


The comment and spec link reference "execute-script" but this endpoint is for async script execution at "/session/{sessionId}/execute/async". The comment should reference "https://www.w3.org/TR/webdriver2/#execute-async-script" instead.

Suggested change

// https://www.w3.org/TR/webdriver2/#execute-script

// https://www.w3.org/TR/webdriver2/#execute-async-script

Copilot · 2025-11-18T12:24:43Z

src/vaev-webdriver/mod.cpp

@@ -0,0 +1,5 @@
+export module Vaev.Webdriver;


Spelling error: "Intial" should be "Initial" in the module title.

Louciole

i let you fishish the TODO's but overall it looks good, I didn't see big loopholes, well done it's great !

Louciole · 2025-11-18T12:29:36Z

src/vaev-engine/dom/window.cpp

    }

+    Async::Task<> refreshAsync() {
+        co_return co_await loadLocationAsync(document()->url());


is it really useful to return an awaited task ? Isn't it a void function?

Louciole · 2025-11-18T12:34:16Z

src/vaev-engine/dom/serialisation.cpp

+// https://html.spec.whatwg.org/multipage/parsing.html#escapingString
+
+export void escapeString(Io::Emit& e, Io::SScan& s, bool attributeMode = false) {
+    while (not s.ended()) {


Wouldnt it be better to have an encode function to encode different type of content ? This way we can encode URLs (with or without space encoding) without duplicating this code

it wouldnt be in this file tho

Louciole · 2025-11-18T12:38:31Z

src/vaev-engine/dom/serialisation.cpp

+           el->qualifiedName == Html::BGSOUND_TAG or
+           el->qualifiedName == Html::FRAME_TAG or
+           el->qualifiedName == Html::KEYGEN_TAG or
+           el->qualifiedName == Html::PARAM_TAG;


ewww i dont like having two void elements thingys, we don't have the choice but I want to complain about the spec

Louciole · 2025-11-18T12:40:25Z

src/vaev-engine/dom/serialisation.cpp

+
+    // 5. For each child node of the node, in tree order:
+    //    1. Let current node be the child node being processed.
+    for (auto currentNode : node->iterChildren()) {


isnt this a width first iterator ? Tree order is depth first

Louciole · 2025-11-18T12:41:58Z

src/vaev-engine/dom/serialisation.cpp

Louciole · 2025-11-18T12:50:09Z

src/vaev-webdriver/driver.cpp

+
+    // https://www.w3.org/TR/webdriver2/#maximize-window
+    Res<> maximizeWindow() {
+        return Error::unsupported("unsupported operation");


Louciole · 2025-11-18T12:52:21Z

src/vaev-webdriver/driver.cpp

+        // https://github.com/web-platform-tests/wpt/blob/bbfc05f2af01d92e2c5af0f8a37b580e233f48f1/tools/wptrunner/wptrunner/executors/executorwebdriver.py#L1070
+        if (contains(body, R"js(return [window.outerWidth - window.innerWidth,
+                       window.outerHeight - window.innerHeight];")js"s)) {
+            return Ok(Serde::Array{0, 0});


ahaha ! funny, will do the job

Louciole · 2025-11-18T12:53:23Z

src/vaev-webdriver/driver.cpp

+        }
+
+        // https://github.com/web-platform-tests/wpt/blob/master/tools/wptrunner/wptrunner/executors/test-wait.js
+        else if (contains(body, R"js(const initialized = !!window.__wptrunner_url;)js"s)) {


shoulb work, we'll see

Louciole · 2025-11-18T13:04:43Z

src/vaev-webdriver/protocol.cpp

+    Print::Orientation orientation = Print::Orientation::PORTRAIT;
+    f64 scale = 1.0;
+    bool background = false;
+    bool shrinkToFit = true;


Louciole · 2025-11-18T13:13:38Z

src/vaev-webdriver/service.cpp

I really like the architecture ! Well done !

sleepy-monax added 4 commits November 18, 2025 13:10

vaev-dom: Implemented dom serialization.

d279f0e

vaev-style: Made getting viewport size from media more ergonomic.

ea4403d

vaev-style: Replaced f16 by f32 for opacity, because not every platfo…

483bfea

…rm support f16.

vaev-webdriver: Initial implementation of webdriver2.

fca9a92

sleepy-monax requested review from Louciole and Copilot November 18, 2025 12:19

Copilot started reviewing on behalf of sleepy-monax November 18, 2025 12:21 View session

Copilot finished reviewing on behalf of sleepy-monax November 18, 2025 12:23

Copilot AI reviewed Nov 18, 2025

View reviewed changes

Louciole requested changes Nov 18, 2025

View reviewed changes

	auto pageHeight = page.getOr("width", 27.94);
	auto pageHeight = page.getOr("height", 27.94);

	Duration implicit = Duration::fromMSecs(9);
	Duration implicit = Duration::fromMSecs(0); // Per WebDriver spec, default is 0ms (no implicit wait)

	if (not orientation.isStr() or (orientation.asStr() != "landscape"s and orientation.asStr() != "landscape"s)) {
	if (not orientation.isStr() or (orientation.asStr() != "landscape"s and orientation.asStr() != "portrait"s)) {

	auto margin = parameters.getOr("page", Serde::Object{});
	auto margin = parameters.getOr("margin", Serde::Object{});

	// https://www.w3.org/TR/webdriver2/#execute-script
	// https://www.w3.org/TR/webdriver2/#execute-async-script

vaev-webdriver: Intial implementation of webdriver2. #129

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vaev-webdriver: Intial implementation of webdriver2. #129

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