MMR Calculator

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Development ​

Prerequisites ​

  • Bun (the package manager — workspaces are apps/* and packages/*)
  • A Riot API key from developer.riotgames.com (a dev key is fine for local work)
  • A Cloudflare account if you want to test against real D1/KV

Setup ​

bash
bun install

Create apps/web/.dev.vars for local secrets:

RIOT_API_KEY=RGAPI-xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx

Apply migrations to the local D1 instance:

bash
bunx wrangler d1 migrations apply mmr-calculator --local

Common commands ​

bash
bun run dev          # SvelteKit + wrangler dev (localhost:5173)
bun run build        # vite build → SvelteKit cloudflare adapter → DO/cron injection
bun test             # vitest with the workers pool
bun run typecheck    # svelte-check + tsc --noEmit across all workspaces
bun run lint         # biome check
bun run format       # biome format --write

bun run docs:dev     # vitepress dev server
bun run docs:build   # build static site to docs/.vitepress/dist

What bun run build does ​

  1. vite build produces the SvelteKit output under apps/web/.svelte-kit/cloudflare/.
  2. apps/web/scripts/inject-do.mjs runs:
    • Bundles RateLimiterDO from src/lib/server/rate-limiter.do.ts into _rate_limiter_do.js.
    • Bundles the scheduled() cron handler from src/lib/server/cron.ts into _cron.js.
    • Rewrites _worker.js to re-export the DO class and to add the cron handler.

This wrapper exists because @sveltejs/adapter-cloudflare does not natively know about Durable Object class exports or scheduled handlers.

Adding a new API route ​

Create apps/web/src/routes/api/v1/<name>/+server.ts. SvelteKit picks it up automatically. For shared logic, prefer adding helpers under apps/web/src/lib/server/ rather than expanding the +server.ts file inline.

Testing the estimator math ​

packages/core is pure — no Worker bindings, no fetch. Run its tests directly:

bash
bun --cwd packages/core test

For tests that need bindings (DB, KV, Riot client), vitest run at the root will use the @cloudflare/vitest-pool-workers pool to spin up a Miniflare environment.