valw/docs/test-checklist.md

valw: end-of-project test checklist

Manual checks on niri that each phase leaves for one test pass once every phase is done. Each phase appends its own section; nothing here blocks a phase from landing. Automated checks (cargo clippy, cargo nextest, nix flake check) still run per phase.

Before starting: update copland's lock (nix flake update valw in ~/copland), rebuild, and check that valw doctor is all ok.

Preview drag-out (2026-10-02)

Already seen working while building it: a drop into Telegram delivered the image, a cancel brought the thumbnail back, and a swipe still dismissed it.

• Drop into Dolphin → the file is copied (the default name has spaces, so this also checks %20).
• Drop into a browser upload field → it uploads.
• Drop into a Discord message → it attaches.
• Drop into an image editor that takes image/png → the pixels arrive.
• Release on nothing, or Esc mid-drag → the thumbnail comes back.
• With timeout_secs = 3, hold a drag past 3 s, then release on nothing → it slides out.
• While dragging, press Print → after the capture the other thumbnails come back but the dragged one doesn't; finishing the drag then behaves normally.
• Same, with 5 thumbnails on that output and the oldest one being dragged → the dragged one is never evicted.
• A fast flick to the left and an immediate release → the thumbnail comes back (or the drag runs normally); it never stays invisible.
• Drag onto the other monitor and drop there → it works.
• Swipe right still dismisses; a click still opens Satty (installed build).

Known minors (deferred from the drag-out review)

• A drag-out press that never became a drag (no data device, or a second drag refused) ignores an expired timer; it should slide out on release.
• A receiver that opens its pipe O_NONBLOCK can get a truncated large PNG; clear O_NONBLOCK in the writer thread.
• A press during the slide-in gives a shifted grab point; use (x - offset, y).
• A swipe released back near its start opens Satty (Phase 2 behaviour); a locked swipe should never become a click.
• The (hidden, dragging) visibility/input decision has no unit test; extract it as a pure function.