Low-traffic neighbourhood tool v2

This is a new version of ltn.abstreet.org. It doesn't have all features from v1 yet, but it solves many problems with the original. Please try both versions and give feedback.

Developer docs

Installation

You'll need: npm, wasm-pack, and cargo.

cd web, and then:

• npm i to install dependencies
• npm run wasm to rebuild the Rust backend
  • vite doesn't automatically rebuild when you edit things
• npm run dev to run locally
  • Changes to the Svelte/CSS usually auto-reload in your browser
• npm run fmt to auto-format code
• npm run check to see TypeScript errors

The tests directory has some diff-based tests. cd backend; cargo test --release will run them.

Architecture

The Rust backend crate gets compiled to WASM, with generally type-unsafe APIs in lib.rs. The Svelte frontend calls these in the main thread (though moving to web workers later is a possibility). The "important" state is kept in the backend, while the frontend has more ephemeral UI state. The main state is serialized as GeoJSON and kept in the user's browser local storage. The frontend is effectively a single page app, with the Mode toggling between different pages.