Audit F-014. pmacs-gpu had 40 tests but none exercised the wgpu
composition path — layout/render regressions passed silently, a human
eyeball the only gate. This adds the first tests that actually render a
frame, headless, and read the pixels back.
Enabling refactor (least-invasive; not the Renderer-sub-struct split):
- `State.window`/`.surface` become `Option`; a shared `assemble(...)`
builds the window-agnostic half, called by both the windowed `new`
and a `#[cfg(test)] new_headless(w, h, text)` (compatible_surface:
None, returns None when no adapter). `request_redraw` is now an
Option-guarded helper across its 15 sites; `resize` guards
`surface.configure`.
- `render()` splits into a surface-acquire wrapper + window-agnostic
`render_to_view(&TextureView)`; `#[cfg(test)] render_offscreen()`
renders through the same path into a RENDER_ATTACHMENT|COPY_SRC
texture and reads it back (256-byte row alignment).
Two smoke tests through the real composition path: a full frame is
non-uniform (something composited); setting text changes the frame vs an
empty buffer. They skip when no adapter is present, except under
`PMACS_REQUIRE_GPU` (CI) where a missing adapter is a hard failure.
CI: a "GPU Render (headless)" job installs mesa-vulkan-drivers
(lavapipe) and runs `cargo test -p pmacs-gpu` — also the first time
pmacs-gpu's tests run in CI at all (the workspace test job covers only
the root package).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_014TXbAwk27agwhrNNrhLi2U
Levi Neuwirth
a5f1372b3e