21 KiB
Testing Strategy
Overview
GridPilot employs a comprehensive BDD (Behavior-Driven Development) testing strategy across three distinct layers: Unit, Integration, and End-to-End (E2E). Each layer validates different aspects of the system while maintaining a consistent Given/When/Then approach that emphasizes behavior over implementation.
This document provides practical guidance on testing philosophy, test organization, tooling, and execution patterns for GridPilot.
BDD Philosophy
Why BDD for GridPilot?
GridPilot manages complex business rules around league management, team registration, event scheduling, result processing, and standings calculation. These rules must be:
- Understandable by non-technical stakeholders (league admins, race organizers)
- Verifiable through automated tests that mirror real-world scenarios
- Maintainable as business requirements evolve
BDD provides a shared vocabulary (Given/When/Then) that bridges the gap between domain experts and developers, ensuring tests document expected behavior rather than technical implementation details.
Given/When/Then Format
All tests—regardless of layer—follow this structure:
// Given: Establish initial state/context
// When: Perform the action being tested
// Then: Assert the expected outcome
Example (Unit Test):
describe('League Domain Entity', () => {
it('should add a team when team limit not reached', () => {
// Given
const league = new League('Summer Series', { maxTeams: 10 });
const team = new Team('Racing Legends');
// When
const result = league.addTeam(team);
// Then
expect(result.isSuccess()).toBe(true);
expect(league.teams).toContain(team);
});
});
This pattern applies equally to integration tests (with real database operations) and E2E tests (with full UI workflows).
Test Types & Organization
Unit Tests (/tests/unit)
Scope: Domain entities, value objects, and application use cases with mocked ports (repositories, external services).
Tooling: Vitest (fast, TypeScript-native, ESM support)
Execution: Parallel, target <1 second total runtime
Purpose:
- Validate business logic in isolation
- Ensure domain invariants hold (e.g., team limits, scoring rules)
- Test use case orchestration with mocked dependencies
Examples from Architecture:
-
Domain Entity Test:
// League.addTeam() validation Given a League with maxTeams=10 and 9 current teams When addTeam() is called with a valid Team Then the team is added successfully Given a League with maxTeams=10 and 10 current teams When addTeam() is called Then a DomainError is returned with "Team limit reached" -
Use Case Test:
// GenerateStandingsUseCase Given a League with 5 teams and completed races When execute() is called Then LeagueRepository.findById() is invoked And ScoringRule.calculatePoints() is called for each team And sorted standings are returned -
Scoring Rule Test:
// ScoringRule.calculatePoints() Given a F1-style scoring rule (25-18-15-12-10-8-6-4-2-1) When calculatePoints(position=1) is called Then 25 points are returned Given the same rule When calculatePoints(position=11) is called Then 0 points are returned
Key Practices:
- Mock only at architecture boundaries (ports like
ILeagueRepository) - Never mock domain entities or value objects
- Keep tests fast (<10ms per test)
- Use in-memory test doubles for simple cases
Integration Tests (/tests/integration)
Scope: Repository implementations, infrastructure adapters (PostgreSQL, Redis, OAuth clients, result importers).
Tooling: Vitest + Testcontainers (spins up real PostgreSQL/Redis in Docker)
Execution: Sequential, ~10 seconds per suite
Purpose:
- Validate that infrastructure adapters correctly implement port interfaces
- Test database queries, migrations, and transaction handling
- Ensure external API clients handle authentication and error scenarios
Examples from Architecture:
-
Repository Test:
// PostgresLeagueRepository Given a PostgreSQL container is running When save() is called with a League entity Then the league is persisted to the database And findById() returns the same league with correct attributes -
OAuth Client Test:
// IRacingOAuthClient Given valid iRacing credentials When authenticate() is called Then an access token is returned And the token is cached in Redis for 1 hour Given expired credentials When authenticate() is called Then an AuthenticationError is thrown -
Result Importer Test:
// EventResultImporter Given an Event exists in the database When importResults() is called with iRacing session data Then Driver entities are created/updated And EventResult entities are persisted with correct positions/times And the Event status is updated to 'COMPLETED'
Key Practices:
- Use Testcontainers to spin up real databases (not mocks)
- Clean database state between tests (truncate tables or use transactions)
- Seed minimal test data via SQL fixtures
- Test both success and failure paths (network errors, constraint violations)
End-to-End Tests (/tests/e2e)
Scope: Full user workflows spanning web-client → web-api → database.
Tooling: Playwright + Docker Compose (orchestrates all services)
Execution: ~2 minutes per scenario
Purpose:
- Validate complete user journeys from UI interactions to database changes
- Ensure services integrate correctly in a production-like environment
- Catch regressions in multi-service workflows
Examples from Architecture:
-
League Creation Workflow:
Given an authenticated league admin When they navigate to "Create League" And fill in league name, scoring system, and team limit And submit the form Then the league appears in the admin dashboard And the database contains the new league record And the league is visible to other users -
Team Registration Workflow:
Given a published league with 5/10 team slots filled When a team captain navigates to the league page And clicks "Join League" And fills in team name and roster And submits the form Then the team appears in the league's team list And the team count updates to 6/10 And the captain receives a confirmation email -
Automated Result Import:
Given a League with an upcoming Event And iRacing OAuth credentials are configured When the scheduled import job runs Then the job authenticates with iRacing And fetches session results for the Event And creates EventResult records in the database And updates the Event status to 'COMPLETED' And triggers standings recalculation -
Companion App Login Automation:
Given a League Admin enables companion app login automation When the companion app is launched Then the app polls for a generated login token from web-api And auto-fills iRacing credentials from the admin's profile And logs into iRacing automatically And confirms successful login to web-api
Key Practices:
- Use Playwright's Page Object pattern for reusable UI interactions
- Test both happy paths and error scenarios (validation errors, network failures)
- Clean database state between scenarios (via API or direct SQL)
- Run E2E tests in CI before merging to main branch
Test Data Strategy
Fixtures & Seeding
Unit Tests:
- Use in-memory domain objects (no database)
- Factory functions for common test entities:
function createTestLeague(overrides?: Partial<LeagueProps>): League { return new League('Test League', { maxTeams: 10, ...overrides }); }
Integration Tests:
- Use Testcontainers to spin up fresh PostgreSQL instances
- Seed minimal test data via SQL scripts:
-- tests/integration/fixtures/leagues.sql INSERT INTO leagues (id, name, max_teams) VALUES ('league-1', 'Test League', 10); - Clean state between tests (truncate tables or rollback transactions)
E2E Tests:
- Pre-seed database via migrations before Docker Compose starts
- Use API endpoints to create test data when possible (validates API behavior)
- Database cleanup between scenarios:
// tests/e2e/support/database.ts export async function cleanDatabase() { await sql`TRUNCATE TABLE event_results CASCADE`; await sql`TRUNCATE TABLE events CASCADE`; await sql`TRUNCATE TABLE teams CASCADE`; await sql`TRUNCATE TABLE leagues CASCADE`; }
Docker E2E Setup
Architecture
E2E tests run against a full stack orchestrated by docker-compose.test.yml:
services:
postgres:
image: postgres:16
environment:
POSTGRES_DB: gridpilot_test
POSTGRES_USER: test
POSTGRES_PASSWORD: test
redis:
image: redis:7-alpine
web-api:
build: ./src/apps/web-api
depends_on:
- postgres
- redis
environment:
DATABASE_URL: postgres://test:test@postgres:5432/gridpilot_test
REDIS_URL: redis://redis:6379
ports:
- "3000:3000"
Execution Flow
- Start Services:
docker compose -f docker-compose.test.yml up -d - Run Migrations:
npm run migrate:test(seeds database) - Execute Tests: Playwright targets
http://localhost:3000 - Teardown:
docker compose -f docker-compose.test.yml down -v
Environment Setup
# tests/e2e/setup.ts
export async function globalSetup() {
// Wait for web-api to be ready
await waitForService('http://localhost:3000/health');
// Run database migrations
await runMigrations();
}
export async function globalTeardown() {
// Stop Docker Compose services
await exec('docker compose -f docker-compose.test.yml down -v');
}
BDD Scenario Examples
1. League Creation (Success + Failure)
Scenario: Admin creates a new league
Given an authenticated admin user
When they submit a league form with:
| name | Summer Series 2024 |
| maxTeams | 12 |
| scoringSystem | F1 |
Then the league is created successfully
And the admin is redirected to the league dashboard
And the database contains the new league
Scenario: League creation fails with duplicate name
Given a league named "Summer Series 2024" already exists
When an admin submits a league form with name "Summer Series 2024"
Then the form displays error "League name already exists"
And no new league is created in the database
2. Team Registration (Success + Failure)
Scenario: Team registers for a league
Given a published league with 5/10 team slots
When a team captain submits registration with:
| teamName | Racing Legends |
| drivers | Alice, Bob, Carol |
Then the team is added to the league
And the team count updates to 6/10
And the captain receives a confirmation email
Scenario: Registration fails when league is full
Given a published league with 10/10 team slots
When a team captain attempts to register
Then the form displays error "League is full"
And the team is not added to the league
3. Automated Result Import (Success + Failure)
Scenario: Import results from iRacing
Given a League with an Event scheduled for today
And iRacing OAuth credentials are configured
When the scheduled import job runs
Then the job authenticates with iRacing API
And fetches session results for the Event
And creates EventResult records for each driver
And updates the Event status to 'COMPLETED'
And triggers standings recalculation
Scenario: Import fails with invalid credentials
Given an Event with expired iRacing credentials
When the import job runs
Then an AuthenticationError is logged
And the Event status remains 'SCHEDULED'
And an admin notification is sent
4. Parallel Scoring Calculation
Scenario: Calculate standings for multiple leagues concurrently
Given 5 active leagues with completed events
When the standings recalculation job runs
Then each league's standings are calculated in parallel
And the process completes in <5 seconds
And all standings are persisted correctly
And no race conditions occur (validated via database integrity checks)
5. Companion App Login Automation
Scenario: Companion app logs into iRacing automatically
Given a League Admin enables companion app login automation
And provides their iRacing credentials
When the companion app is launched
Then the app polls web-api for a login token
And retrieves the admin's encrypted credentials
And auto-fills the iRacing login form
And submits the login request
And confirms successful login to web-api
And caches the session token for 24 hours
Coverage Goals
Target Coverage Levels
- Domain/Application Layers: >90% (critical business logic)
- Infrastructure Layer: >80% (repository implementations, adapters)
- Presentation Layer: Smoke tests (basic rendering, no exhaustive UI coverage)
Running Coverage Reports
# Unit + Integration coverage
npm run test:coverage
# View HTML report
open coverage/index.html
# E2E coverage (via Istanbul)
npm run test:e2e:coverage
What to Prioritize
- Domain Entities: Invariants, validation rules, state transitions
- Use Cases: Orchestration logic, error handling, port interactions
- Repositories: CRUD operations, query builders, transaction handling
- Adapters: External API clients, OAuth flows, result importers
What NOT to prioritize:
- Trivial getters/setters
- Framework boilerplate (Express route handlers)
- UI styling (covered by visual regression tests if needed)
Continuous Testing
Watch Mode (Development)
# Auto-run unit tests on file changes
npm run test:watch
# Auto-run integration tests (slower, but useful for DB work)
npm run test:integration:watch
CI/CD Pipeline
graph LR
A[Code Push] --> B[Unit Tests]
B --> C[Integration Tests]
C --> D[E2E Tests]
D --> E[Deploy to Staging]
Execution Order:
- Unit Tests (parallel, <1 second) — fail fast on logic errors
- Integration Tests (sequential, ~10 seconds) — catch infrastructure issues
- E2E Tests (sequential, ~2 minutes) — validate full workflows
- Deploy — only if all tests pass
Parallelization:
- Unit tests run in parallel (Vitest default)
- Integration tests run sequentially (avoid database conflicts)
- E2E tests run sequentially (UI interactions are stateful)
Testing Best Practices
1. Test Behavior, Not Implementation
❌ Bad (overfitted to implementation):
it('should call repository.save() once', () => {
const repo = mock<ILeagueRepository>();
const useCase = new CreateLeagueUseCase(repo);
useCase.execute({ name: 'Test' });
expect(repo.save).toHaveBeenCalledTimes(1);
});
✅ Good (tests observable behavior):
it('should persist the league to the repository', async () => {
const repo = new InMemoryLeagueRepository();
const useCase = new CreateLeagueUseCase(repo);
const result = await useCase.execute({ name: 'Test' });
expect(result.isSuccess()).toBe(true);
const league = await repo.findById(result.value.id);
expect(league?.name).toBe('Test');
});
2. Mock Only at Architecture Boundaries
Ports (interfaces) should be mocked in use case tests:
const mockRepo = mock<ILeagueRepository>({
save: jest.fn().mockResolvedValue(undefined),
});
Domain entities should NEVER be mocked:
// ❌ Don't do this
const mockLeague = mock<League>();
// ✅ Do this
const league = new League('Test League', { maxTeams: 10 });
3. Keep Tests Readable and Maintainable
Arrange-Act-Assert Pattern:
it('should calculate standings correctly', () => {
// Arrange: Set up test data
const league = createTestLeague();
const teams = [createTestTeam('Team A'), createTestTeam('Team B')];
const results = [createTestResult(teams[0], position: 1)];
// Act: Perform the action
const standings = league.calculateStandings(results);
// Assert: Verify the outcome
expect(standings[0].team).toBe(teams[0]);
expect(standings[0].points).toBe(25);
});
4. Test Error Scenarios
Don't just test the happy path:
describe('League.addTeam()', () => {
it('should add team successfully', () => { /* ... */ });
it('should fail when team limit reached', () => {
const league = createTestLeague({ maxTeams: 1 });
league.addTeam(createTestTeam('Team A'));
const result = league.addTeam(createTestTeam('Team B'));
expect(result.isFailure()).toBe(true);
expect(result.error.message).toBe('Team limit reached');
});
it('should fail when adding duplicate team', () => { /* ... */ });
});
Common Patterns
Setting Up Test Fixtures
Factory Functions:
// tests/support/factories.ts
export function createTestLeague(overrides?: Partial<LeagueProps>): League {
return new League('Test League', {
maxTeams: 10,
scoringSystem: 'F1',
...overrides,
});
}
export function createTestTeam(name: string): Team {
return new Team(name, { drivers: ['Driver 1', 'Driver 2'] });
}
Mocking Ports in Use Case Tests
// tests/unit/application/CreateLeagueUseCase.test.ts
describe('CreateLeagueUseCase', () => {
let mockRepo: jest.Mocked<ILeagueRepository>;
let useCase: CreateLeagueUseCase;
beforeEach(() => {
mockRepo = {
save: jest.fn().mockResolvedValue(undefined),
findById: jest.fn().mockResolvedValue(null),
findByName: jest.fn().mockResolvedValue(null),
};
useCase = new CreateLeagueUseCase(mockRepo);
});
it('should create a league when name is unique', async () => {
const result = await useCase.execute({ name: 'New League' });
expect(result.isSuccess()).toBe(true);
expect(mockRepo.save).toHaveBeenCalledWith(
expect.objectContaining({ name: 'New League' })
);
});
});
Database Cleanup Strategies
Integration Tests:
// tests/integration/setup.ts
import { sql } from './database';
export async function cleanDatabase() {
await sql`TRUNCATE TABLE event_results CASCADE`;
await sql`TRUNCATE TABLE events CASCADE`;
await sql`TRUNCATE TABLE teams CASCADE`;
await sql`TRUNCATE TABLE leagues CASCADE`;
}
beforeEach(async () => {
await cleanDatabase();
});
E2E Tests:
// tests/e2e/support/hooks.ts
import { test as base } from '@playwright/test';
export const test = base.extend({
page: async ({ page }, use) => {
// Clean database before each test
await fetch('http://localhost:3000/test/cleanup', { method: 'POST' });
await use(page);
},
});
Playwright Page Object Pattern
// tests/e2e/pages/LeaguePage.ts
export class LeaguePage {
constructor(private page: Page) {}
async navigateToCreateLeague() {
await this.page.goto('/leagues/create');
}
async fillLeagueForm(data: { name: string; maxTeams: number }) {
await this.page.fill('[name="name"]', data.name);
await this.page.fill('[name="maxTeams"]', data.maxTeams.toString());
}
async submitForm() {
await this.page.click('button[type="submit"]');
}
async getSuccessMessage() {
return this.page.textContent('.success-message');
}
}
// Usage in test
test('should create league', async ({ page }) => {
const leaguePage = new LeaguePage(page);
await leaguePage.navigateToCreateLeague();
await leaguePage.fillLeagueForm({ name: 'Test', maxTeams: 10 });
await leaguePage.submitForm();
expect(await leaguePage.getSuccessMessage()).toBe('League created');
});
Cross-References
ARCHITECTURE.md— Layer boundaries, port definitions, and dependency rules that guide test structureTECH.md— Detailed tooling specifications (Vitest, Playwright, Testcontainers configuration)package.json— Test scripts and commands (test:unit,test:integration,test:e2e,test:coverage)
Summary
GridPilot's testing strategy ensures:
- Business logic is correct (unit tests for domain/application layers)
- Infrastructure works reliably (integration tests for repositories/adapters)
- User workflows function end-to-end (E2E tests for full stack)
By following BDD principles and maintaining clear test organization, the team can confidently evolve GridPilot while preserving correctness and stability.