kata-typescript

A TypeScript DSA practice harness based on ThePrimeagen/kata-machine. Generate a fresh set of typed kata stubs each day, implement them, and use the original test suite for feedback.

Usage

npm install
npm run generate
# Implement the stubs in src/current
npm test
npm run clear

npm run clear archives your work before deleting it — see Attempts.

Edit ligma.config.ts to choose the daily katas. npm test runs only the matching files because vitest.config.ts derives its include list from that config. npm run day prints the current generated directory.

Study loop

npm run due -- --generate  # generate today's Interval exercises
npm run day                # print the directory to work in
npm test                   # repeat while implementing the stubs
npm run clear              # archive the attempt and reset

After the tests pass, grade the attempt in Interval before clearing it. Use npm run due -- --all to see the full schedule, npm run archive to save without clearing, or npm run generate -- BinarySearchList to practice one kata directly. Run npm run prettier to format the repo. The -- passes the remaining arguments to the underlying script.

Attempts

src/current is gitignored and npm run clear deletes it, so implementations are throwaway by default. Before deleting, clear copies each one into attempts/<Kata>/<date>-<result>.ts, which is committed:

attempts/
  BinarySearchList/
    2026-08-03-failing.ts
    2026-08-17-passing.ts

Untouched stubs are skipped, so only real work is kept. The result comes from a vitest run against src/current. Run npm run archive on its own to snapshot without deleting, or npm run clear -- --no-archive to skip it.

This deliberately isn't an answer key. A canonical solution sitting next to the exercise turns a retrieval rep into a recognition rep — the kata still feels done, you grade it Had to think, and the schedule drifts. Your own past attempt carries the same information but has to be dug for, and it's written in your idiom, so reading it reconstructs your reasoning rather than teaching you someone else's. Diffing two passing attempts weeks apart also shows what's actually consolidating, which the Instant/Had-to-think/Blanked grade can't capture.

Interval sync

Regenerating all 23 katas every day is massed practice. This repo can instead pair with Interval, a spaced-repetition trainer that schedules each form on its own review curve — you re-implement only what's actually decaying, and grade the attempt in the app.

Setup:

1. In Interval, open the Katas tab and seed the 23 kata-machine forms.
2. Click Sync in the app header to enable cross-device sync. The pairing link it gives you ends in #k=<key>.
3. Copy .env.example to .env in this repo and set KATA_SYNC_KEY=<key>.

Then:

npm run due                # today's work: reviews that are due, plus a couple of new forms
npm run due -- --generate  # scaffold stubs for exactly those
npm run due -- --all       # the full table, including forms not started yet
npm run due -- --new 5     # introduce more new forms today than usual

Unseen forms are introduced a couple per day rather than all at once, so a fresh seed doesn't hand you all 23 on day one. The rate comes from the app's newPerDay setting; --new overrides it for a single run. Reviews are never withheld — the cap only limits how fast new forms enter rotation.

New forms enter in ligma.config.ts order, so that list doubles as the introduction ramp — reorder it to change which forms you meet first.

Implement the generated stubs until vitest passes, then grade the attempt in Interval's Katas tab (Instant / Had to think / Blanked) — that's what schedules the next rep. Each kata in the app links back to the chapter of The Last Algorithms Course You'll Need that builds it.

The sync key is a 128-bit capability: anyone holding it can read and write your training state, so keep .env out of version control (it's gitignored here).

This port moves the catalog, generator, cleanup script, and configuration to TypeScript, replaces Jest with Vitest 3, and updates the project to TypeScript 5, Prettier 3, and tsx.

The original kata-machine is Copyright (c) ThePrimeagen and distributed under the MIT License. This TypeScript port retains that attribution and is also MIT-licensed.