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Testing ​

Problem ​

Implement testing in a production-friendly way with @vielzeug/logit while keeping setup and cleanup explicit.

Runnable Example ​

The snippet below is copy-paste runnable in a TypeScript project with @vielzeug/logit installed.

ts
import { Logit } from '@vielzeug/logit';
import { afterEach, beforeEach, expect, it, vi } from 'vitest';

beforeEach(() => {
  Logit.setConfig({ logLevel: 'off' });
});

afterEach(() => {
  Logit.setConfig({ logLevel: 'debug' });
  vi.restoreAllMocks();
});

it('emits errors when enabled', () => {
  Logit.setConfig({ logLevel: 'error' });
  const spy = vi.spyOn(console, 'error').mockImplementation(() => {});

  Logit.error('failure');

  expect(spy).toHaveBeenCalled();
});

Expected Output ​

  • The example runs without type errors in a standard TypeScript setup.
  • The main flow produces the behavior described in the recipe title.

Common Pitfalls ​

  • Forgetting cleanup/dispose calls can leak listeners or stale state.
  • Skipping explicit typing can hide integration issues until runtime.
  • Not handling error branches makes examples harder to adapt safely.