@mado/invariant

Installation

npm install @mado/invariant
# or
yarn add @mado/invariant
# or
pnpm add @mado/invariant

Usage

invariant

Basic Usage

import { invariant } from '@mado/invariant';

const creature = { name: 'Dragon', type: 'Fire' };

invariant(creature.name === 'Dragon', 'Creature must be a Dragon');

Using Callback for Error Message

import { invariant } from '@mado/invariant';

const creature = { name: 'Elf', type: 'Forest' };

invariant(creature.type === 'Water', () => 'Creature must be of type Water');

invariantResponse

Basic Usage

import { invariantResponse } from '@mado/invariant';

const creature = { name: 'Phoenix', type: 'Fire' };

invariantResponse(creature.type === 'Fire', 'Creature must be of type Fire');

Using Callback for Response Message

import { invariantResponse } from '@mado/invariant';

const creature = { name: 'Mermaid', type: 'Water' };

invariantResponse(
  creature.type === 'Land',
  () => `Expected a Land creature, but got a ${creature.type} creature`,
);

Throwing a Response with Additional Options

import { invariantResponse } from '@mado/invariant';

const creature = { name: 'Cerberus', type: 'Underworld' };

invariantResponse(
  creature.type === 'Sky',
  JSON.stringify({ error: 'Creature must be of type Sky' }),
  { status: 500, headers: { 'Content-Type': 'text/json' } },
);

isInvariantError

import { invariant, isInvariantError } from '@mado/invariant';

try {
  const creature = { name: 'Mermaid', type: 'Water' };

  invariant(creature.name === 'Dragon', 'Creature must be a Dragon');
} catch (error) {
  if (isInvariantError(error)) {
    // ...
  }
}