fix(vtz): apply requested viewport before rendering screenshots [#2949]#3022
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viniciusdacal merged 1 commit intomainfrom Apr 28, 2026
Merged
fix(vtz): apply requested viewport before rendering screenshots [#2949]#3022viniciusdacal merged 1 commit intomainfrom
viniciusdacal merged 1 commit intomainfrom
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`vertz_browser_screenshot` was rendering every PNG at the launch viewport (1280x720) regardless of the `viewport` arg passed to the MCP tool. The metadata reported the requested dimensions back, but the rasterized image and on-disk filename did not match — cross-viewport visual QA (the #2865 dogfood goal) was unusable. `ChromiumoxideHandle::capture` now opens a blank page first, applies `Emulation.setDeviceMetricsOverride` with `req.viewport`, and only then navigates to the URL — so responsive layouts see the requested viewport from the initial render. Adds a regression test that decodes the PNG IHDR header and asserts the rendered dimensions match the request, plus unit coverage for the PNG-dimension helper. Closes #2949. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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Summary
vertz_browser_screenshotignoredviewport.width/heightand always rendered 1280x720.ChromiumoxideHandle::capturenow opensabout:blank, appliesEmulation.setDeviceMetricsOverridewithreq.viewport, then navigates — so responsive layouts see the requested viewport from the initial render.Public API Changes
None. Internal screenshot pipeline only.
Test plan
cargo test -p vtz --lib server::screenshot(125 passed, 2 ignored)cargo clippy -p vtz --all-targets -- -D warnings(clean)cargo fmt --all -- --check(clean)cargo test -p vtz --lib server::screenshot::chromium -- --ignored --test-threads=1real_chrome_captures_about_blank✅real_chrome_honors_request_viewport✅ (the regression case)🤖 Generated with Claude Code