skuba-dive v2.0.0

🤿🌊

Minimal runtime for skuba.

Table of contents

• API reference
  • Assert
  • Env
  • Register
• Design

API reference

Assert

TypeScript assertion functions for narrowing down types in unit tests and the like.

These may be used for input validation in your application code at a pinch, but consider a proper validation library with richer error handling and reporting.

import { Assert } from 'skuba-dive';

it('should think of a good test case name', () => {
  const result = numberOrNull();
  // result is number | null

  Assert.notNullish(result);
  // result is number
});

Env

Functions for reading values out of environment variables.

For example, in your /src/config.ts:

import { Env } from 'skuba-dive';

const ENVIRONMENTS = ['dev', 'prod'] as const;

export type Environment = (typeof ENVIRONMENTS)[number];

export const environment = Env.oneOf(ENVIRONMENTS)('ENVIRONMENT');
// 'dev' | 'prod'

export const port = Env.nonNegativeInteger('PORT', { default: undefined });
// number | undefined

export const version = Env.string('VERSION', { default: 'local' });
// string | 'local'

export const flag = Env.boolean('FLAG');
// boolean

Each function will throw if its environment variable is not set and opts.default is not provided.

Register

Runtime hook for import paths relative to /src.

Make a side-effectful import at the top of your entry point(s):

// /src/register.ts

import 'skuba-dive/register';

// /src/app.ts

import './register';

import { config } from 'src/config';

export = new Koa();

The hook must be imported from a module that sits directly under /src for module resolution to work correctly.

Design

skuba-dive packages up:

• General application boilerplate that doesn't justify a standalone module
• Runtime functionality that complements skuba

See skuba's goals and non-goals for more information.