loopr
Repeat any GPX loop into a longer ride.
Drop a .gpx of one lap, pick how many times to ride it (or a target distance), download a stitched GPX you can import into Strava, Ride With GPS, Garmin Connect, or Wahoo. Everything happens in the browser — your file never leaves your device.
Live at loopr.willcsoftware.com.
What it does
- Parse GPX (multi-segment, multi-track, with routes and waypoints).
- Repeat each
<trk> N times with the seam deduped between laps.
- Optionally drop a waypoint at the start of each lap so your bike computer can show them.
- Strip
<time> (this isn't a ride — it's a plan).
- Compute distance, elevation gain/loss, and max gradient over a 100m moving window for a live summary.
- Emit valid GPX 1.1 with
creator="loopr <version>".
Stack
- SvelteKit + Svelte 5 (runes), TypeScript strict
@sveltejs/adapter-static → GitHub Pages- Vitest + Playwright
- pnpm
Develop
corepack enable
pnpm install
pnpm dev
Verify
pnpm check # svelte-check + tsc
pnpm test:unit # vitest, GPX library
pnpm test:e2e # functional, accessibility, responsive, and visual browser suite
pnpm test:e2e:functional # all browser checks except screenshot comparisons
pnpm test:visual # compare committed screenshots across desktop and mobile browsers
pnpm validate # complete pre-push check: types, lint, unit, UI, and visual tests
pnpm build # static output → build/
pnpm preview # serves build/ at :4173
The UI contract runs in desktop Chromium, Firefox, and WebKit, plus Pixel/Chrome and
iPhone/WebKit profiles. WebKit is the repeatable CI proxy for Safari. Before changing the UI
intentionally, refresh and inspect baselines on macOS with pnpm test:visual:update, then commit
the images under tests/e2e/__screenshots__. CI compares them on the macOS 26 arm64 runner to
minimize platform-specific rendering differences from local Apple Silicon Macs.
Playwright's WebKit build is not the exact Safari binary shipped by macOS. For a release-level
Safari check, run the suite locally on macOS and do a short manual pass in the current Safari;
CI still catches the large majority of WebKit-specific layout and behavior regressions on every PR.
MIT, © 2026 WillC Software House.
