db-test

Generate integration tests using Testcontainers for real database validation.

Testcontainers by Language

.NET

public class CandidateRepositoryTests : IAsyncLifetime
{
    private readonly PostgreSqlContainer _container = new PostgreSqlBuilder()
        .WithImage("postgres:16-alpine").Build();
    public async Task InitializeAsync() => await _container.StartAsync();
    public async Task DisposeAsync() => await _container.DisposeAsync();
}

Java

@Testcontainers
class UserRepositoryTests {
    @Container
    static PostgreSQLContainer<?> postgres = new PostgreSQLContainer<>("postgres:16-alpine");
}

Node.js / TypeScript

import { PostgreSqlContainer } from '@testcontainers/postgresql';
let container: StartedPostgreSqlContainer;
beforeAll(async () => { container = await new PostgreSqlContainer().start(); });
afterAll(async () => { await container.stop(); });

Go

container, _ := testcontainers.GenericContainer(ctx, testcontainers.GenericContainerRequest{
    ContainerRequest: testcontainers.ContainerRequest{
        Image: "postgres:16-alpine", ExposedPorts: []string{"5432/tcp"},
    }, Started: true,
})

Strategies

• Transaction rollback: wrap test, rollback after (fastest)
• Truncate: RESTART IDENTITY CASCADE between tests
• Fixtures: Object Mother + Builder patterns, Faker for realistic data
• CI: Docker services with health checks, migrations before tests
• Single-entity reads must complete in < 100ms under test load

Arguments

• <repository-name>: Repository class to test
• --provider=<cosmosdb|postgres|mysql|mongodb|redis>: Database provider