bessa_patterns.ts

Library of Reusable Design Patterns in TypeScript

Installation

npm install bessa_patterns.ts

Patterns

| Class | Pattern | Description | | --------------------- | -------- | --------------------------------------------------------------------- | | ObserverSubject<T> | Observer | Typed callback-based subject — subscribe/notify with typed snapshots | | DualObserverSubject | Observer | GoF + function-based dual subject — two independent observer channels |

Quick Example

import { ObserverSubject } from 'bessa_patterns.ts';

const counter = new ObserverSubject<{ count: number }>();
const unsub = counter.subscribe(({ count }) => console.log(count));

counter.notify({ count: 1 }); // 1
counter.notify({ count: 2 }); // 2
unsub();

Deployment

scripts/deploy.sh builds and publishes the package to npm. It is invoked automatically by ai-workflow deploy or manually:

export NPM_TOKEN=<your-npm-token>
bash scripts/deploy.sh

Alternatively, place the token in a gitignored .env file at the project root and the deploy script loads it automatically:

# .env  (never committed)
NPM_TOKEN=<your-npm-token>

An explicit export NPM_TOKEN=... in the environment takes precedence over the .env value.

Prerequisites:

• NPM_TOKEN must be set — via the environment or a .env file at the project root (publish auth token)
• npm must be available on PATH

What it does (in order):

1. npm ci — clean dependency install
2. npm test — all tests must pass
3. npm run build — TypeScript compiled to dist/
4. npm publish --access public — publishes to the npm registry

Exit codes: 0 on success; non-zero on any failure (guard failures abort immediately via set -euo pipefail).

Troubleshooting

| Symptom | Cause | Fix | | ------------------------------------- | ----------------------------------------- | --------------------------------------------------------------- | | Error: npm ERR! 401 Unauthorized | NPM_TOKEN is missing or expired | Run export NPM_TOKEN=<valid-token> before invoking the script | | Script aborts at npm test step | One or more tests are failing | Run npm test locally, fix failures, then retry the deploy | | npm ERR! network / registry timeout | Transient npm registry connectivity issue | Retry; if persistent, check https://status.npmjs.org |

Documentation

• Documentation Index
• Getting Started
• API Reference
• DualObserverSubject API
• Architecture
• Roadmap
• Changelog
• Contributing

Development

| Tool / Directory | Purpose | | ----------------------- | ----------------------------------------------------------------------------------------- | | npm test | Run all Jest tests | | npm run test:coverage | Run tests with coverage report (output to coverage/; 80% threshold enforced) | | npm run lint | Lint with ESLint (eslint.config.mjs) | | npm run build | Compile TypeScript to dist/ via tsc | | .husky/ | Husky Git hooks — runs lint and tests before commits |