ScholastiCoder

Free, hands-on coding lessons that run in your browser: 32 courses across programming languages, the web, tools and computer science, with an emphasis on Python. Live at https://aquinas22.github.io/scholasticoder/.

What is inside

• One simple lesson pattern. Every lesson reads the same way: a short explanation with runnable examples, a common question answered plainly (with the usual mix-ups explained), checked exercises, and a quick quiz. 61 common questions across 22 courses are indexed at /questions. See /method.

• Clickable key words. Terms in lesson prose link to the glossary: click one for a definition, an example and the course that teaches it (src/lib/terms.ts, src/components/Term.tsx).

• Run code in the browser. Every Python code block has a Run button, backed by a real CPython interpreter (Pyodide) running in a Web Worker. JavaScript blocks run in an isolated worker, TypeScript is compiled with the real compiler (types erased) then run the same way, SQL blocks run on SQLite (sql.js) against a seeded sample database, and HTML and CSS blocks get a live sandboxed preview.

• Graded exercises. Python, JavaScript, TypeScript and SQL lessons end with exercises that are checked automatically, with progressive hints and a reference solution. The Terminal and Bash paths have exercises in a simulated shell (src/lib/shell-sim.ts) with a virtual file system, pipes, redirection, globs and tab completion. Quick-check quizzes reinforce the ideas and count toward progress.

• The Playground (/dojo): a Python, JavaScript, TypeScript and shell playground with example programs, program input for input(), a virtual file system, on-demand scientific packages, and shareable links.

• Python challenges (/challenges): 34 checked problems from FizzBuzz to Dijkstra, in four levels (Basics, Core, Intermediate, Advanced).

• Progress (/progress) is stored in the browser (localStorage). No accounts, no tracking. A glossary (/glossary) links every term to the course that teaches it.

• Themes. Light and Dark site themes (Automatic follows the device setting), plus editor classics: Gruvbox, Tokyo Night, Catppuccin, Nord, Dracula, Solarized, One Dark, Rosé Pine, Monokai, GitHub. Defined in src/lib/themes.ts; every palette recolours the code editors too.

Develop

npm install
npm run dev        # http://localhost:3000/scholasticoder/
npm run lint
npm run build      # static export to ./out

The site is a static Next.js export deployed to GitHub Pages by .github/workflows/deploy.yml on every push to main.

Content layout

Path	Purpose
src/content/languages/*.ts	One file per course: setup, lessons, sections
src/content/python-practice.ts, js-practice.ts, ts-practice.ts, sql-practice.ts, shell-practice.ts	Exercises and quizzes merged into the Python, JavaScript, TypeScript, SQL, Terminal and Bash lessons
src/content/languages/python-extra.ts	Additional Python lessons (strings, regex, JSON, collections, recursion, debugging)
src/content/challenges.ts	The Python challenges
src/content/glossary.ts	Glossary entries, with examples and the words that link to them in prose
src/content/quaestiones*.ts	Common questions merged into lessons (Python, web, tools, systems). The file and type names are historical.
src/lib/sql-seed.ts	The sample database every SQL block queries
src/lib/shell-sim.ts	The simulated bash shell used by shell exercises and the Playground
src/lib/themes.ts	Colour palettes
src/content/cheatsheets.ts, field-guides.ts	Per-course reference material
public/workers/python-worker.js	The Pyodide worker that runs learner code

Writing an exercise

{
  type: 'exercise',
  content: 'Prompt shown to the learner.',
  exercise: {
    title: 'Short name',
    starter: 'def solve():\n    ...\n',
    solution: 'def solve():\n    return 42\n',
    hints: ['First nudge', 'Second nudge'],
    tests: [
      // `check` is Python executed in the learner's namespace after their program.
      // `_out` holds everything they printed; `_src` holds their source.
      { name: 'Returns 42', check: 'assert solve() == 42' },
    ],
  },
}

JavaScript checks use assert, assert.equal and assert.deepEqual in the learner's scope. SQL checks are queries that must return a truthy value; the learner's last result set is available as the temp table _result.

Shell exercises use type: 'shell' with check functions that receive the simulator state. Code sections default to runnable when their language is Python, JavaScript, TypeScript, SQL, HTML or CSS; set runnable: false on blocks that need a real machine (sockets, GUIs, subprocesses, PostgreSQL-only syntax).