Testing Plugins

Testing Plugins

The @ecommus/testing package provides mock factories and a test app harness for testing plugins and custom business logic.

Installation

npm install --save-dev @ecommus/testing

Or if you are working in the monorepo, it is already available.

Mock Factories

createMockOrder

import { createMockOrder } from '@ecommus/testing';

const order = createMockOrder({
  total: 15000,          // in smallest currency unit (bani)
  currency: 'RON',
  status: 'paid',
  items: [
    { productId: 'prod_1', qty: 2, price: 7500 }
  ]
});

Partial fields are merged with sensible defaults. All generated IDs use the ecommus cuid2 format.

createMockProduct

import { createMockProduct } from '@ecommus/testing';

const product = createMockProduct({
  name: 'Test Product',
  price: 9900,
  stock: 10
});

createMockCustomer

import { createMockCustomer } from '@ecommus/testing';

const customer = createMockCustomer({
  email: 'test@example.com',
  tags: ['vip']
});

createMockTenant

import { createMockTenant } from '@ecommus/testing';

const tenant = createMockTenant({ slug: 'test-store' });

Test App Harness

createTestApp bootstraps a real Fastify instance with an in-memory pglite database — ideal for integration tests.

import { createTestApp, createMockTenant } from '@ecommus/testing';
import { describe, it, expect, beforeAll, afterAll } from 'vitest';

describe('My Plugin Integration', () => {
  let app: Awaited<ReturnType<typeof createTestApp>>;

  beforeAll(async () => {
    app = await createTestApp({
      plugins: ['../plugins/my-plugin/src/index.ts']
    });
  });

  afterAll(async () => {
    await app.close();
  });

  it('registers its routes', async () => {
    const res = await app.inject({
      method: 'GET',
      url: '/api/my-plugin/health',
    });
    expect(res.statusCode).toBe(200);
  });
});

Unit Testing Business Logic

For pure business logic in packages/core, test functions directly with vitest:

import { describe, it, expect } from 'vitest';
import { computeItemTotal } from '@ecommus/core';

describe('computeItemTotal', () => {
  it('applies quantity discount', () => {
    const result = computeItemTotal({ price: 1000, qty: 3, discount: 0.1 });
    expect(result).toBe(2700); // 3 × 1000 × 0.9
  });
});

Running Tests

# All tests in monorepo
npx vitest run

# Only a specific package
npx vitest run --project packages/core

# With coverage
npx vitest run --coverage

CI Integration

Tests run automatically on every push via .github/workflows/ci.yml:

- run: npx vitest run
  working-directory: packages/core

The @ecommus/testing package is also used in the CI pipeline to validate plugin compatibility across versions.