Scientific Witchery

Source for jackyoustra.com — Jack Youstra's blog, plus a couple of interactive tools that run entirely in the browser:

• /binary — drops a Mach-O/ELF binary in and charts its size breakdown, using Twiggy and Bloaty compiled to WebAssembly.
• /converter — "Pdx Converter": pastes in a Paradox (Clausewitz) save or script file and converts it to JSON, via the jomini Rust crate compiled to WASM.
• /projects/quiz — a BuzzFeed-style quiz.

Stack

• Next.js 14 (App Router) + React 18
• Contentlayer2 turns data/blog/*.mdx into typed content at build time; MDX pipeline includes KaTeX math, Prism syntax highlighting, GFM, and autolinked headings.
• Tailwind CSS for styling, next-themes for dark mode.
• Rust → WebAssembly in rust-wasm/, built with wasm-pack and consumed as a local path dependency ("rust-wasm": "./rust-wasm/pkg").
• ECharts for the binary-size visualisations; Umami and Vercel Analytics for analytics. There is no comment system — the Giscus config in data/siteMetadata.js and .env.example is kept, unwired, for a later restore.

Running it

Requires bun. Node is only needed for the postbuild scripts, which bun shells out to.

bun install
bun run dev      # http://localhost:3000

Other scripts:

command	what it does
bun run build	production build, then scripts/postbuild.mjs writes the RSS feeds
bun run wasm	rebuild rust-wasm/pkg (only needed after editing rust-wasm/src/)
bun run lint	eslint with --fix
bun run spell	cspell over the posts
bun run cypress:open	end-to-end tests

bun run spell is advisory, not a gate: it currently exits non-zero, almost entirely on compiler flags and tracebacks inside fenced code blocks, which cspell.json does not exclude.

bun run cypress:open expects the site already running on port 3002 — cypress.config.ts and cypress/e2e/spec.cy.ts both hardcode it, and no script in package.json binds that port, so start one yourself (bunx next start -p 3002 after a build).

Copy .env.example to .env.local and fill in what you need; everything in it is optional for local development.

Writing

Posts are MDX files in data/blog/. Frontmatter fields are declared in velite.config.ts — title, date and summary are required, the rest (tags, lastmod, draft, images, authors, series, part) are not. Tags are lowercased and slugified (github-slugger) before they become /tags/<tag> routes, so write them lowercase in frontmatter. Site configuration lives in data/siteMetadata.js, nav links in data/headerNavLinks.ts, and the projects page reads data/projectsData.ts.

Two per-post values are computed rather than written: socialImage (declared images:, else the first card-friendly local body image, else the site banner) and the readingMinutes / readingMinutesWithCode pair.

Deploying

Deploys are manual, from a local machine, via the Vercel CLI. See DEPLOY.md.

Licence

MIT — see LICENSE, which retains the copyright notice of the starter template this site grew out of alongside Jack's own.