# Testing Specification

## Job to Be Done

When I make changes to the codebase, I want automated tests to catch regressions, so that I can deploy with confidence.

## Testing Strategy

PhaseFlow uses a **three-tier testing approach**: unit tests, integration tests, and end-to-end tests.

### Test Types

| Type | Scope | Tools | Location |
|------|-------|-------|----------|
| Unit | Pure functions, utilities | Vitest | Colocated `*.test.ts` |
| Integration | API routes, PocketBase interactions | Vitest + supertest | Colocated `*.test.ts` |
| E2E | Full user flows, browser interactions | Playwright | `e2e/*.spec.ts` |

## Framework

**Vitest** - Fast, Vite-native test runner with TypeScript support.

**Configuration (`vitest.config.ts`):**
```typescript
import { defineConfig } from 'vitest/config';

export default defineConfig({
  test: {
    globals: true,
    environment: 'node',
    include: ['src/**/*.test.ts'],
    coverage: {
      provider: 'v8',
      reporter: ['text', 'html'],
    },
  },
});
```

## Unit Tests

Test pure functions in isolation without external dependencies.

### Priority Targets

| Module | Functions | Priority |
|--------|-----------|----------|
| `src/lib/cycle.ts` | `getCycleDay`, `getPhase`, `getPhaseConfig` | High |
| `src/lib/decision-engine.ts` | `getTrainingDecision` | High |
| `src/lib/nutrition.ts` | `getNutritionGuidance`, `getSeeds`, `getMacros` | Medium |
| `src/lib/ics.ts` | `generatePhaseEvents`, `generateCalendarFeed` | Medium |
| `src/lib/encryption.ts` | `encrypt`, `decrypt` | Medium |

### Example Test

```typescript
// src/lib/cycle.test.ts
import { describe, it, expect } from 'vitest';
import { getCycleDay, getPhase } from './cycle';

describe('getCycleDay', () => {
  it('returns 1 on period start date', () => {
    const lastPeriod = new Date('2024-01-01');
    const today = new Date('2024-01-01');
    expect(getCycleDay(lastPeriod, 31, today)).toBe(1);
  });

  it('handles cycle rollover', () => {
    const lastPeriod = new Date('2024-01-01');
    const today = new Date('2024-02-01'); // Day 32
    expect(getCycleDay(lastPeriod, 31, today)).toBe(1);
  });
});

describe('getPhase', () => {
  it('returns MENSTRUAL for days 1-3', () => {
    expect(getPhase(1, 31)).toBe('MENSTRUAL');
    expect(getPhase(3, 31)).toBe('MENSTRUAL');
  });

  it('scales correctly for 28-day cycle', () => {
    // LATE_LUTEAL should be days 22-28 for 28-day cycle
    expect(getPhase(22, 28)).toBe('LATE_LUTEAL');
    expect(getPhase(21, 28)).toBe('EARLY_LUTEAL');
  });
});
```

## Integration Tests

Test API routes and PocketBase interactions.

### Setup

Use a test PocketBase instance or PocketBase's testing utilities.

```typescript
// src/test/setup.ts
import PocketBase from 'pocketbase';

export const testPb = new PocketBase(process.env.TEST_POCKETBASE_URL);

beforeAll(async () => {
  // Setup test data
});

afterAll(async () => {
  // Cleanup
});
```

### Priority Targets

| Route | Tests |
|-------|-------|
| `GET /api/today` | Returns decision with valid auth |
| `GET /api/cycle/current` | Returns correct phase info |
| `POST /api/cycle/period` | Updates user record |
| `GET /api/user` | Returns authenticated user |
| `PATCH /api/user` | Updates user fields |
| `GET /api/health` | Returns health status |

### Example Test

```typescript
// src/app/api/today/route.test.ts
import { describe, it, expect } from 'vitest';
import { GET } from './route';

describe('GET /api/today', () => {
  it('returns 401 without auth', async () => {
    const request = new Request('http://localhost/api/today');
    const response = await GET(request);
    expect(response.status).toBe(401);
  });

  it('returns decision with valid auth', async () => {
    // Setup authenticated request
    const request = new Request('http://localhost/api/today', {
      headers: { Cookie: 'pb_auth=...' },
    });
    const response = await GET(request);
    expect(response.status).toBe(200);

    const data = await response.json();
    expect(data).toHaveProperty('decision');
    expect(data).toHaveProperty('cycleDay');
  });
});
```

## End-to-End Tests

Test complete user flows through the browser using Playwright.

### Framework

**Playwright** - Cross-browser E2E testing with auto-waiting and tracing.

**Configuration (`playwright.config.ts`):**
```typescript
import { defineConfig, devices } from "@playwright/test";

export default defineConfig({
  testDir: "./e2e",
  fullyParallel: true,
  forbidOnly: !!process.env.CI,
  retries: process.env.CI ? 2 : 0,
  reporter: [["html", { open: "never" }], ["list"]],
  use: {
    baseURL: "http://localhost:3000",
    trace: "on-first-retry",
    screenshot: "only-on-failure",
  },
  projects: [
    { name: "chromium", use: { ...devices["Desktop Chrome"] } },
  ],
  webServer: {
    command: "pnpm dev",
    url: "http://localhost:3000",
    reuseExistingServer: !process.env.CI,
  },
});
```

### Priority Targets

| Flow | Tests |
|------|-------|
| Authentication | Login page loads, login redirects, logout works |
| Dashboard | Shows decision, displays cycle info, override toggles work |
| Settings | Garmin token paste, preferences save |
| Calendar | ICS feed accessible, calendar view renders |
| Period logging | "Period Started" updates cycle |

### Example Test

```typescript
// e2e/dashboard.spec.ts
import { expect, test } from "@playwright/test";

test.describe("dashboard", () => {
  test("shows training decision for authenticated user", async ({ page }) => {
    // Login first (or use auth state)
    await page.goto("/");

    // Verify decision card is visible
    await expect(page.getByTestId("decision-card")).toBeVisible();

    // Verify cycle day is displayed
    await expect(page.getByText(/Day \d+ of \d+/)).toBeVisible();
  });

  test("override toggles update decision", async ({ page }) => {
    await page.goto("/");

    // Enable flare mode
    await page.getByLabel("Flare Mode").click();

    // Decision should change to gentle
    await expect(page.getByText(/GENTLE/)).toBeVisible();
  });
});
```

### NixOS Setup

E2E tests require browser binaries. On NixOS, use `playwright-web-flake`:

```nix
# In flake.nix inputs
inputs.playwright-web-flake.url = "github:pietdevries94/playwright-web-flake/1.56.1";

# In devShell
PLAYWRIGHT_BROWSERS_PATH = "${playwright-driver.browsers}";
PLAYWRIGHT_SKIP_BROWSER_DOWNLOAD = "1";
```

## File Naming

Tests colocated with source files (unit/integration) or in `e2e/` directory (E2E):

```
src/
  lib/
    cycle.ts
    cycle.test.ts
    decision-engine.ts
    decision-engine.test.ts
  app/
    api/
      today/
        route.ts
        route.test.ts
e2e/
  smoke.spec.ts
  dashboard.spec.ts
  auth.spec.ts
  settings.spec.ts
```

## Running Tests

```bash
# Run unit/integration tests
pnpm test:run

# Run in watch mode
pnpm test

# Run E2E tests (headless)
pnpm test:e2e

# Run E2E tests (visible browser)
pnpm test:e2e:headed

# Run E2E tests with UI mode
pnpm test:e2e:ui

# Run all tests (unit + E2E)
pnpm test:run && pnpm test:e2e
```

## Coverage Expectations

No strict coverage thresholds for MVP, but aim for:
- 80%+ coverage on `src/lib/` (core logic)
- Key API routes tested for auth and happy path

## Success Criteria

1. All tests (unit, integration, E2E) pass in CI before merge
2. Core decision engine logic has comprehensive unit tests
3. Phase scaling tested for multiple cycle lengths
4. API auth tested for protected routes
5. Critical user flows covered by E2E tests

## Acceptance Tests

- [ ] `pnpm test:run` runs without errors
- [ ] `pnpm test:e2e` runs without errors
- [ ] Unit tests cover decision engine logic
- [ ] Unit tests cover cycle phase calculations
- [ ] Integration tests verify API authentication
- [ ] E2E tests verify login flow
- [ ] E2E tests verify dashboard displays correctly
- [ ] E2E tests verify period logging works
- [ ] Tests run in CI pipeline