test(cua-driver/windows): robustify slider_drag coords + web CDP-port isolation

[f-trycua]

Two Windows harness tests flagged in the overnight harness sweep. Both are test-side — the driver paths are correct (VM-confirmed); no driver bug.

harness_wpf_slider_drag

The hardcoded drag y=275 landed ~29px above the slider track (which sits at window-local y≈304, on empty GroupBox space), so the thumb never moved — but the SendInput/foreground-drag path itself is fine: the UIA-Invoke companion (harness_wpf_slider_increase_large) passes, and corrected coords advance the value. Moved the drag to the track row (44,304)→(330,304).

• ✅ Verified on the VM (Session 2): ✅ Sent drag via SendInput … (358,306)→(644,306) → thumb tracked → 1 passed.
• TODO (noted in-code): derive the coords from the sld-value element frame for DPI/placement independence.

harness_web_test (CDP-port isolation)

The 5 web tests use fixed CDP ports (9222/9223) + a process-global CUA_DRIVER_CDP_PORT, so they must run serially (--test-threads=1). A prior host still releasing its port let the daemon discover the stale host's pages[0] (the click then lands on the wrong window, counter check fails). Added wait_port_free() before launch to close the teardown-overlap window.

• ✅ Verified on the VM (serial): 5 passed (incl. harness_electron_click_element: … counter=1).

No driver code touched. (Latent driver hardening noted for later: cdp_list_pages picks pages[0] on a fixed env port with no correlation to the requested window — could hit the wrong Chromium app in production if two expose CDP.)

🤖 Generated with Claude Code

Summary by CodeRabbit

• Bug Fixes
  • Improved reliability of automated runs when reusing the same local port, reducing failures caused by stale processes.
  • Made drag interactions in the Windows UI more consistent by using fixed window-relative coordinates, helping avoid misaligned drags on different displays or DPI settings.

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1 Skipped Deployment

Project	Deployment	Actions	Updated (UTC)
docs	Ignored		Jun 26, 2026 6:41pm

[coderabbitai]

Caution

Review failed

The pull request is closed.

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: 792f36d3-1a71-419b-b35b-278f71d8270f

📥 Commits

Reviewing files that changed from the base of the PR and between 6b2b262 and 8e9e9c7.

📒 Files selected for processing (2)

• libs/cua-driver/rust/crates/cua-driver/tests/harness_web_test.rs
• libs/cua-driver/rust/crates/cua-driver/tests/harness_wpf_test.rs

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📝 Walkthrough

Walkthrough

The web test harness now waits for the fixed CDP port to be free before starting a new session, and the WPF slider drag test now uses explicit window-local coordinates with updated comments.

Changes

Web harness port readiness

Layer / File(s)	Summary
Port-free wait before session libs/cua-driver/rust/crates/cua-driver/tests/harness_web_test.rs	A polling helper checks localhost TCP availability for the CDP port and is called before spawning the harness host.

WPF slider drag coordinates

Layer / File(s)	Summary
Window-local drag inputs libs/cua-driver/rust/crates/cua-driver/tests/harness_wpf_test.rs	The slider drag command replaces screen-derived coordinates with documented window-local values for the track and thumb.

Sequence Diagram(s)

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Possibly related PRs

• trycua/cua#1705: Changes in this PR update the same WPF slider drag test and coordinate inputs.
• trycua/cua#1708: This PR also adjusts drag coordinate handling to resolve a coordinate-space mismatch.

Poem

A bunny hopped by CDP’s door,
Waited till the port bound no more.
🐇 Then slid with care,
Through window-space air,
And landed the drag right on the floor.

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch test/harness-windows-robustness

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[github-actions]

Linux visual regression artifacts

Matrix jobs now run independently. Download visual artifacts from this workflow run.
Each background-GUI job uploads a .gif of the interaction plus two annotated PNGs (<app>.png raw, <app>-atspi.png with AT-SPI element boxes); the cua-driver-linux-som-overlays artifact adds <app>-som.png cua Set-of-Marks overlays:

• cua-driver-linux-cursor-click-gif
• cua-driver-linux-background-terminal-gif
• cua-driver-linux-parallel-drag-xserver
• cua-driver-linux-background-gui-chromium
• cua-driver-linux-background-gui-tk
• cua-driver-linux-background-gui-gtk3-gedit
• cua-driver-linux-background-gui-gtk3-mousepad
• cua-driver-linux-background-gui-gtk3-scite
• cua-driver-linux-background-gui-gtk4-characters
• cua-driver-linux-background-gui-qt5-manuskript
• cua-driver-linux-background-gui-qt5-klog
• cua-driver-linux-background-gui-qt5-openambit
• cua-driver-linux-background-gui-qt6-kate
• cua-driver-linux-background-gui-qt6-kcalc
• cua-driver-linux-background-gui-qt6-okular
• cua-driver-linux-background-gui-qt6-qownnotes
• cua-driver-linux-background-gui-electron-zettlr
• cua-driver-linux-background-gui-electron-joplin
• cua-driver-linux-background-gui-electron-logseq
• cua-driver-linux-som-overlays

Open workflow run and download artifacts