sentryagent-idp/docs/engineering/09-testing.md

09 — Testing Strategy

---

10.1 Test Types and Purposes

This codebase uses two types of tests. Understanding when to use each prevents you from writing integration tests for things that should be unit tests (slow) and unit tests for things that need a real database (misleading).

Unit Tests

Location: tests/unit/

What they test: A single class or function in complete isolation. All dependencies (repositories, services, external clients) are replaced with Jest mocks.

When to use:

• Testing service business logic (free-tier limits, status transitions, error cases)
• Testing utility functions (crypto, jwt, validators)
• Testing error hierarchy behaviour
• Any code that has conditional logic you want to test exhaustively

What they do NOT test:

• Whether the SQL queries are correct
• Whether the HTTP routing works
• Whether middleware chains execute in the right order

Speed: Milliseconds. Hundreds of unit tests should complete in under 10 seconds.

Integration Tests

Location: tests/integration/

What they test: A full HTTP request through the Express application against a real PostgreSQL database and real Redis instance.

When to use:

• Testing that a route is correctly wired to the right controller method
• Testing authentication and authorisation middleware in combination
• Testing database operations end-to-end (INSERT → read back → verify)
• Testing response shapes match the OpenAPI spec exactly

What they require:

• Running PostgreSQL (at TEST_DATABASE_URL or default)
• Running Redis (at TEST_REDIS_URL or default)
• The test creates its own tables and cleans up after every test case

Speed: Seconds. Expect 2–5 seconds per integration test file.

---

10.2 Test Framework Stack

Tool	Role
Jest 29.7	Test runner. describe, it, expect, beforeEach, afterAll. Also provides mocking via jest.mock(), jest.fn(), jest.spyOn().
ts-jest	Transforms TypeScript test files for Jest without a separate compilation step. Configured in jest.config.ts.
Supertest 6.3	HTTP testing library. Used in integration tests to make real HTTP requests against the Express app without opening a network port. Works by passing the Application object directly.

Jest configuration (jest.config.ts):

export default {
  preset: 'ts-jest',
  testEnvironment: 'node',
  roots: ['<rootDir>/tests'],
  testPathPattern: ['tests/unit', 'tests/integration'],
  collectCoverageFrom: ['src/**/*.ts', '!src/server.ts'],
};

---

10.3 Coverage Gates

All four coverage metrics must be above 80% before a feature is considered complete:

Metric	Gate	What it means
Statements	>80%	Each statement was executed at least once
Branches	>80%	Each if/else/switch branch was taken at least once
Functions	>80%	Each function was called at least once
Lines	>80%	Each line was executed at least once

Enforcement:

Coverage is checked in the PR process:

npm run test:unit -- --coverage
# Fails if any metric is below 80%

Coverage reports are output to coverage/lcov-report/index.html for visual inspection.

The coverage threshold configuration is in jest.config.ts:

coverageThreshold: {
  global: {
    statements: 80,
    branches: 80,
    functions: 80,
    lines: 80,
  },
},

---

10.4 How to Run the Test Suite

# Run all tests (unit + integration)
npm test

# Run only unit tests
npm run test:unit

# Run only integration tests
npm run test:integration

# Run unit tests with coverage report
npm run test:unit -- --coverage
# HTML report: coverage/lcov-report/index.html

# Run a single test file
npx jest tests/unit/services/AgentService.test.ts

# Run tests matching a name pattern
npx jest --testNamePattern="should throw FreeTierLimitError"

# Run tests in watch mode (re-runs on file changes)
npx jest --watch

# Run with verbose output (shows each test name)
npx jest --verbose

Integration test environment variables:

export TEST_DATABASE_URL=postgresql://sentryagent:sentryagent@localhost:5432/sentryagent_idp_test
export TEST_REDIS_URL=redis://localhost:6379/1
npm run test:integration

Using database index /1 for Redis in tests prevents test runs from polluting the main database (index 0) used for local development.

---

10.5 Unit Test Writing Conventions

Unit tests follow a strict pattern. Study this example carefully — it shows every convention in use.

Real example from tests/unit/services/AgentService.test.ts:

/**
 * Unit tests for src/services/AgentService.ts
 */

import { AgentService } from '../../../src/services/AgentService';
import { AgentRepository } from '../../../src/repositories/AgentRepository';
import { CredentialRepository } from '../../../src/repositories/CredentialRepository';
import { AuditService } from '../../../src/services/AuditService';
import {
  AgentAlreadyExistsError,
  FreeTierLimitError,
} from '../../../src/utils/errors';
import { IAgent, ICreateAgentRequest } from '../../../src/types/index';

// Mock all dependencies — none of them execute real code
jest.mock('../../../src/repositories/AgentRepository');
jest.mock('../../../src/repositories/CredentialRepository');
jest.mock('../../../src/services/AuditService');

// Get typed mock constructors so we can call .mockResolvedValue() on them
const MockAgentRepository = AgentRepository as jest.MockedClass<typeof AgentRepository>;
const MockCredentialRepository = CredentialRepository as jest.MockedClass<typeof CredentialRepository>;
const MockAuditService = AuditService as jest.MockedClass<typeof AuditService>;

// Define a complete test fixture — reuse this instead of duplicating object literals
const MOCK_AGENT: IAgent = {
  agentId: 'a1b2c3d4-e5f6-7890-abcd-ef1234567890',
  email: 'agent@sentryagent.ai',
  agentType: 'screener',
  version: '1.0.0',
  capabilities: ['resume:read'],
  owner: 'team-a',
  deploymentEnv: 'production',
  status: 'active',
  createdAt: new Date('2026-03-28T09:00:00Z'),
  updatedAt: new Date('2026-03-28T09:00:00Z'),
};

describe('AgentService', () => {
  let agentService: AgentService;
  let agentRepo: jest.Mocked<AgentRepository>;
  let credentialRepo: jest.Mocked<CredentialRepository>;
  let auditService: jest.Mocked<AuditService>;

  beforeEach(() => {
    // Clear all mocks before each test — prevents state leakage
    jest.clearAllMocks();
    // Create fresh mock instances for each test
    agentRepo = new MockAgentRepository({} as never) as jest.Mocked<AgentRepository>;
    credentialRepo = new MockCredentialRepository({} as never) as jest.Mocked<CredentialRepository>;
    auditService = new MockAuditService({} as never) as jest.Mocked<AuditService>;
    // Inject mocks into the system under test
    agentService = new AgentService(agentRepo, credentialRepo, auditService);
  });

  describe('registerAgent()', () => {
    const createData: ICreateAgentRequest = {
      email: 'agent@sentryagent.ai',
      agentType: 'screener',
      version: '1.0.0',
      capabilities: ['resume:read'],
      owner: 'team-a',
      deploymentEnv: 'production',
    };

    it('should create and return a new agent', async () => {
      // Arrange — set up mock return values
      agentRepo.countActive.mockResolvedValue(0);
      agentRepo.findByEmail.mockResolvedValue(null);
      agentRepo.create.mockResolvedValue(MOCK_AGENT);
      auditService.logEvent.mockResolvedValue({} as never);

      // Act — call the method under test
      const result = await agentService.registerAgent(createData, '127.0.0.1', 'test/1.0');

      // Assert — verify the result
      expect(result).toEqual(MOCK_AGENT);
      // Also verify the mock was called with the right arguments
      expect(agentRepo.create).toHaveBeenCalledWith(createData);
    });

    it('should throw FreeTierLimitError when 100 agents already registered', async () => {
      // Arrange — simulate limit reached
      agentRepo.countActive.mockResolvedValue(100);

      // Assert error — rejects.toThrow checks the error type
      await expect(agentService.registerAgent(createData, '127.0.0.1', 'test/1.0'))
        .rejects.toThrow(FreeTierLimitError);
    });

    it('should throw AgentAlreadyExistsError if email is already registered', async () => {
      agentRepo.countActive.mockResolvedValue(0);
      agentRepo.findByEmail.mockResolvedValue(MOCK_AGENT); // Simulate existing agent

      await expect(agentService.registerAgent(createData, '127.0.0.1', 'test/1.0'))
        .rejects.toThrow(AgentAlreadyExistsError);
    });
  });
});

Conventions explained:

1. One test file per source file. AgentService.test.ts tests AgentService.ts.
2. jest.mock() before any imports from the mocked module. Jest hoists mock declarations.
3. jest.clearAllMocks() in beforeEach. Prevents mock call counts from leaking between tests.
4. AAA pattern (Arrange, Act, Assert). Every it block follows this order.
5. Test both the happy path and every error case. A service with 3 error conditions needs at least 4 tests (1 success + 3 failures).
6. Verify mock calls for side effects. Use .toHaveBeenCalledWith() to verify that auditService.logEvent was called with the right arguments, not just that it was called.
7. Use typed error assertions. .rejects.toThrow(FreeTierLimitError) verifies the error type, not just a message string.

---

10.6 Integration Test Writing Conventions

Integration tests use Supertest to make real HTTP requests against a live Express app.

Real example from tests/integration/agents.test.ts:

/**
 * Integration tests for Agent Registry endpoints.
 */

import crypto from 'crypto';
import request from 'supertest';
import { Application } from 'express';
import { v4 as uuidv4 } from 'uuid';
import { Pool } from 'pg';

// Generate RSA keys for test tokens — done once per test module
const { privateKey, publicKey } = crypto.generateKeyPairSync('rsa', {
  modulusLength: 2048,
  publicKeyEncoding: { type: 'spki', format: 'pem' },
  privateKeyEncoding: { type: 'pkcs8', format: 'pem' },
});

// Set environment variables BEFORE importing the app
process.env['DATABASE_URL'] = process.env['TEST_DATABASE_URL'] ?? 'postgresql://sentryagent:sentryagent@localhost:5432/sentryagent_idp_test';
process.env['REDIS_URL'] = process.env['TEST_REDIS_URL'] ?? 'redis://localhost:6379/1';
process.env['JWT_PRIVATE_KEY'] = privateKey;
process.env['JWT_PUBLIC_KEY'] = publicKey;
process.env['NODE_ENV'] = 'test';

import { createApp } from '../../src/app';
import { signToken } from '../../src/utils/jwt';
import { closePool } from '../../src/db/pool';
import { closeRedisClient } from '../../src/cache/redis';

// Helper: mint a valid test token
function makeToken(sub: string = uuidv4(), scope: string = 'agents:read agents:write'): string {
  return signToken({ sub, client_id: sub, scope, jti: uuidv4() }, privateKey);
}

describe('Agent Registry Integration Tests', () => {
  let app: Application;
  let pool: Pool;

  beforeAll(async () => {
    // Boot the real Express app
    app = await createApp();
    pool = new Pool({ connectionString: process.env['DATABASE_URL'] });

    // Create test tables (idempotent)
    await pool.query(`CREATE TABLE IF NOT EXISTS agents (...)`);
  });

  afterEach(async () => {
    // Clean up after each test — order matters (foreign key constraints)
    await pool.query('DELETE FROM audit_events');
    await pool.query('DELETE FROM credentials');
    await pool.query('DELETE FROM agents');
  });

  afterAll(async () => {
    // Close all connections — prevents Jest from hanging
    await pool.end();
    await closePool();
    await closeRedisClient();
  });

  describe('POST /api/v1/agents', () => {
    it('should register a new agent and return 201', async () => {
      const token = makeToken();

      const res = await request(app)
        .post('/api/v1/agents')
        .set('Authorization', `Bearer ${token}`)
        .send({
          email: 'test-agent@sentryagent.ai',
          agentType: 'screener',
          version: '1.0.0',
          capabilities: ['resume:read'],
          owner: 'test-team',
          deploymentEnv: 'development',
        });

      expect(res.status).toBe(201);
      expect(res.body.agentId).toBeDefined();
      expect(res.body.email).toBe('test-agent@sentryagent.ai');
      expect(res.body.status).toBe('active');
    });

    it('should return 401 without a token', async () => {
      const res = await request(app)
        .post('/api/v1/agents')
        .send({ email: 'test@sentryagent.ai' });

      expect(res.status).toBe(401);
    });

    it('should return 409 for duplicate email', async () => {
      const token = makeToken();
      const body = { email: 'dup@sentryagent.ai', agentType: 'screener', version: '1.0', capabilities: [], owner: 'team', deploymentEnv: 'development' };

      await request(app).post('/api/v1/agents').set('Authorization', `Bearer ${token}`).send(body);
      const res = await request(app).post('/api/v1/agents').set('Authorization', `Bearer ${token}`).send(body);

      expect(res.status).toBe(409);
      expect(res.body.code).toBe('AGENT_ALREADY_EXISTS');
    });
  });
});

Conventions explained:

1. Set process.env before importing the app. The app reads env vars at import time (getPool(), JWT keys). Setting them after import does nothing.
2. afterEach cleanup. Delete all rows after each test so tests are independent. Always delete in child-to-parent order (audit_events → credentials → agents) to respect foreign key constraints.
3. afterAll close connections. Always close the pool and Redis client at the end of the suite. Jest will hang if connections remain open.
4. Test both success and failure status codes. Every endpoint test must include an unauthenticated request (401) and an invalid request (400).
5. Verify response body shape. Check res.body.code for error responses to verify the correct error type, not just the status code.
6. Use makeToken() for test tokens. A helper function keeps token creation consistent across all integration test files.

---

10.7 OWASP Top 10 Security Testing Reference

These are the security concerns most relevant to an identity provider. For each, here is what AgentIdP does to mitigate the risk and how to test it.

OWASP Category	Relevant risk	Mitigation	Test approach
A01 Broken Access Control	Agent A accesses agent B's credentials	req.user.sub !== agentId check in all credential endpoints	Test: send credential request with a token for agent A but agentId for agent B in the path — expect 403
A02 Cryptographic Failures	Weak credential secrets or JWT algorithm	sk_live_<64 hex> = 256-bit entropy; RS256 signing; bcrypt 10 rounds	Test: verify generated secrets are 72 chars; verify JWT header shows alg: RS256
A03 Injection	SQL injection via input fields	Parameterised queries ($1, $2, ...) in all repositories	Test: send '; DROP TABLE agents; -- as owner field — expect 400 from Joi validation
A05 Security Misconfiguration	Server leaking stack traces	errorHandler returns generic 500 for unknown errors	Test: trigger an unexpected error (mock a repository to throw new Error()) — verify response body does not contain stack trace
A06 Vulnerable Components	Outdated dependencies with CVEs	Regular npm audit	Run: npm audit in CI; fail on high/critical findings
A07 Auth Failures	Timing attack on credential verification	crypto.timingSafeEqual in VaultClient.verifySecret(); bcrypt inherently timing-safe	Test: measure multiple failed verification attempts with wrong secrets of varying lengths — timing should not increase linearly with shared prefix length
A08 Integrity Failures	Forged JWT tokens	RS256 verification rejects tokens signed with wrong key	Test: create a token signed with a different private key — expect 401
A09 Logging Failures	Auth failures not logged	auth.failed audit events written for every authentication failure	Test: attempt token issuance with wrong secret — verify auth_events table contains auth.failed row
A10 SSRF	Not applicable to current API surface	No outbound HTTP from user-supplied URLs	N/A — no URL-accepting fields in current API

JWT algorithm confusion (bonus): Test that the server rejects tokens with alg: none or alg: HS256. The verifyToken() function specifies algorithms: ['RS256'], which causes jsonwebtoken to reject any token with a different algorithm header.

---

10.8 AGNTCY Conformance Test Suite

Location: tests/agntcy-conformance/conformance.test.ts

Purpose: Verifies that the AgentIdP platform conforms to the AGNTCY agent identity specification. These tests exercise live HTTP requests through the Express application against real PostgreSQL and Redis instances, exactly like integration tests — but they validate AGNTCY-specific protocol guarantees rather than individual endpoint correctness.

How to run:

# Run the conformance suite (separate Jest config)
npm run test:agntcy-conformance

# Equivalent long form
npx jest --config tests/agntcy-conformance/jest.config.cjs

# Run with TEST_DATABASE_URL and TEST_REDIS_URL overrides
TEST_DATABASE_URL=postgresql://sentryagent:sentryagent@localhost:5432/sentryagent_idp_test \
TEST_REDIS_URL=redis://localhost:6379/1 \
npm run test:agntcy-conformance

# Enable A2A delegation conformance tests (gated by env var)
A2A_ENABLED=true npm run test:agntcy-conformance

The conformance suite uses its own jest.config.cjs (located in tests/agntcy-conformance/) so it does not run with npm test by default. This is intentional — the suite requires COMPLIANCE_ENABLED=true and optionally A2A_ENABLED=true, which should not be required for the standard unit/integration test run.

What each test validates:

Conformance Test	What it validates	AGNTCY Domain
Conformance 1 — Agent registration creates DID:WEB identifier	POST /api/v1/agents returns a did field matching did:web:* pattern when DID_WEB_DOMAIN is set. The did field is optional in the response (test is conditional on presence) — but when present, it must conform to the did:web: scheme.	Non-Human Identity
Conformance 2 — Token issuance via client_credentials grant	Registers an agent, generates credentials via API, then exercises the full OAuth 2.0 Client Credentials flow. Validates that POST /api/v1/token returns a 200 response with access_token (string), token_type: 'Bearer', and a JWT with 3 dot-separated parts.	Authentication
Conformance 3 — A2A delegation chain create + verify	(Gated by A2A_ENABLED=true.) Creates a delegation chain between two agents via POST /api/v1/oauth2/token/delegate. If a token is returned, verifies it via POST /api/v1/oauth2/token/verify-delegation. Accepts 200 or 201 on creation and 200 or 204 on verification.	Agent-to-Agent Trust
Conformance 4 — Compliance report returns valid AGNTCY structure	Calls GET /api/v1/compliance/report and validates all required AGNTCY fields: generated_at (valid ISO 8601), tenant_id (string), agntcy_schema_version: '1.0', sections (array with name, status, details per entry), overall_status (one of pass/fail/warn). Also verifies the agent-identity and audit-trail section names are present. A second request verifies the Redis cache (X-Cache: HIT header and from_cache: true body field).	Audit, Compliance

Schema tables created by conformance suite: The suite creates its own tables using CREATE TABLE IF NOT EXISTS before tests run. The tables match the production schema and include: organizations, agents, credentials, audit_events, token_revocations, agent_did_keys, delegation_chains. These are cleaned up via DELETE in afterEach (child-to-parent order respecting FK constraints) and dropped implicitly when the test database is reset.

Environment variables used:

Variable	Required	Purpose
TEST_DATABASE_URL	Yes (or default)	PostgreSQL connection string for the test database
TEST_REDIS_URL	Yes (or default)	Redis connection string (index 1 recommended)
COMPLIANCE_ENABLED	Yes ('true')	Enables the compliance report endpoint
A2A_ENABLED	No (default 'true')	Set to 'false' to skip Conformance 3 (A2A delegation)
DID_WEB_DOMAIN	No	When set, Conformance 1 validates the did:web: format

---

10.9 Tier Enforcement Tests

Location: tests/unit/services/TierService.test.ts and tests/integration/

The TierService has the following test cases that must all pass:

Unit tests (tests/unit/services/TierService.test.ts)

The unit tests mock PostgreSQL (Pool) and Redis (RedisClientType) and Stripe. Key scenarios:

Test	Description
getStatus() — returns correct tier and limits	Mocks SELECT tier FROM organizations returning 'pro'; mocks Redis GET calls for rate:tier:calls and rate:tier:tokens; verifies ITierStatus.limits matches TIER_CONFIG['pro'].
getStatus() — falls back to 0 when Redis unavailable	Redis GET throws; verifies usage.callsToday = 0 and usage.tokensToday = 0 with no error thrown.
getStatus() — returns 'free' when org not found	SELECT returns 0 rows; verifies tier === 'free'.
initiateUpgrade() — throws ValidationError on downgrade attempt	targetTier = 'free' when current is 'pro'; verifies ValidationError is thrown with TIER_RANK comparison failure message.
initiateUpgrade() — calls Stripe with correct metadata	Verifies stripe.checkout.sessions.create is called with metadata: { orgId, targetTier } and mode: 'subscription'.
applyUpgrade() — executes UPDATE organizations SET tier	Verifies parameterized SQL is called with [targetTier, orgId].
enforceAgentLimit() — throws TierLimitError when limit reached	Mock agent count equals TIER_CONFIG[tier].maxAgents; verifies TierLimitError with limit and current details.
enforceAgentLimit() — no-op for Enterprise tier	TIER_CONFIG['enterprise'].maxAgents = Infinity; verifies no SQL query for agent count and no error.
fetchTier() — returns 'free' for unknown tier string in DB	DB returns unrecognised string; verifies isTierName guard returns 'free'.

Integration (middleware) tests

When writing integration tests for the tier enforcement middleware (src/middleware/tier.ts), the following scenarios must be covered:

Scenario	Expected behaviour
Request with org on free tier, under daily call limit	Request proceeds normally (2xx from downstream handler)
Request that would exceed maxCallsPerDay for the org's tier	429 TierLimitError — body contains code: 'TIER_LIMIT_EXCEEDED'
Request to /health or /metrics (unprotected routes)	Tier middleware not applied — always 200
Org not found in organizations table	Defaults to free tier limits

---

10.10 Analytics Service Tests

Location: tests/unit/services/AnalyticsService.test.ts

The AnalyticsService unit tests mock the PostgreSQL Pool. Key scenarios that must be covered:

Test	Description
recordEvent() — executes UPSERT without throwing	Verifies pool.query is called with the INSERT ... ON CONFLICT DO UPDATE SQL pattern and the correct [tenantId, metricType] parameters.
recordEvent() — catches and swallows pool errors	Pool query throws; verifies recordEvent resolves (not rejects) and the error does not propagate. This is the fire-and-forget contract.
getTokenTrend() — clamps days to 90	Calls with days = 200; verifies pool.query receives clampedDays = 90 as the first parameter.
getTokenTrend() — maps rows to ITokenTrendEntry[]	Mock returns rows with date: '2026-03-01', count: '42'; verifies the result is [{ date: '2026-03-01', count: 42 }] (count coerced to number).
getAgentActivity() — maps rows to IAgentActivityEntry[]	Mock returns rows with string-typed dow, hour, count; verifies all are coerced to numbers in the result.
getAgentUsageSummary() — maps rows to IAgentUsageSummaryEntry[]	Mock returns rows with token_count: '150'; verifies token_count: 150 (number) in the result.
getAgentUsageSummary() — joins with agents table on organization_id	Verifies the SQL query joins agents with LEFT JOIN analytics_events and filters a.organization_id = $1.

Coverage gate: AnalyticsService must maintain >80% statement, branch, function, and line coverage. Run:

npm run test:unit -- --coverage --testPathPattern=AnalyticsService

---

10.11 Running the Complete Phase 6 Test Matrix

All of the following must pass before any Phase 6 feature is considered complete:

# 1. Unit tests (all services including Phase 3–6)
npm run test:unit -- --coverage
# Must exit 0 with all 4 coverage metrics ≥ 80%

# 2. Integration tests (requires PostgreSQL + Redis running)
npm run test:integration

# 3. AGNTCY conformance suite
COMPLIANCE_ENABLED=true \
A2A_ENABLED=true \
npm run test:agntcy-conformance

# 4. Dependency security audit
npm audit --audit-level=high
# Must exit 0 — no high or critical vulnerabilities

# 5. TypeScript compilation
npx tsc --noEmit
# Must exit 0 — zero type errors

Current test file inventory (as of Phase 6 completion):

Unit test files in tests/unit/services/:

File	Service tested
AgentService.test.ts	AgentService
AnalyticsService.test.ts	AnalyticsService
AuditService.test.ts	AuditService
AuditVerificationService.test.ts	AuditVerificationService
BillingService.test.ts	BillingService
ComplianceService.test.ts	ComplianceService
CredentialService.test.ts	CredentialService
DIDService.test.ts	DIDService
DelegationService.test.ts	DelegationService
EncryptionService.test.ts	EncryptionService
FederationService.test.ts	FederationService
IDTokenService.test.ts	IDTokenService
OAuth2Service.test.ts	OAuth2Service
OIDCKeyService.test.ts	OIDCKeyService
OrgService.test.ts	OrgService
ScaffoldService.test.ts	ScaffoldService
ScaffoldService.errors.test.ts	ScaffoldService error cases
TierService.test.ts	TierService
WebhookService.test.ts	WebhookService