apf_portal/apps/portal-bff/src/auth/auth.service.spec.ts

import type { AuthenticationResult, ConfidentialClientApplication } from '@azure/msal-node';
import { PRE_AUTH_COOKIE_TTL_MS } from './auth.cookie';
import { AuthCodeFlowException } from './auth.errors';
import { AuthService, type PreAuthPayload } from './auth.service';
import type { EntraConfig } from './entra-config.token';

const ENTRA: EntraConfig = {
  instanceUrl: 'https://login.microsoftonline.com/',
  tenantId: 'aaaaaaaa-bbbb-cccc-dddd-eeeeeeeeeeee',
  clientId: '11111111-2222-3333-4444-555555555555',
  clientSecret: 's3cret',
  redirectUri: 'http://localhost:3000/api/auth/callback',
  postLogoutRedirectUri: 'http://localhost:4200/',
  authority: 'https://login.microsoftonline.com/aaaaaaaa-bbbb-cccc-dddd-eeeeeeeeeeee',
};

interface ServiceFixture {
  service: AuthService;
  getAuthCodeUrl: jest.Mock;
  acquireTokenByCode: jest.Mock;
}

function makeService(overrides?: { acquireTokenByCode?: jest.Mock }): ServiceFixture {
  const getAuthCodeUrl = jest.fn().mockResolvedValue('https://entra.example/authorize?…');
  const acquireTokenByCode =
    overrides?.acquireTokenByCode ??
    jest.fn().mockResolvedValue(makeAuthResult({ amr: ['pwd', 'mfa'] }));
  const msalStub = {
    getAuthCodeUrl,
    acquireTokenByCode,
  } as unknown as ConfidentialClientApplication;
  return { service: new AuthService(msalStub, ENTRA), getAuthCodeUrl, acquireTokenByCode };
}

function makeAuthResult(
  claims: Partial<{
    amr: string[];
    oid: string;
    tid: string;
    name: string;
    preferred_username: string;
  }>,
): AuthenticationResult {
  return {
    idTokenClaims: {
      oid: claims.oid ?? 'user-oid',
      tid: claims.tid ?? ENTRA.tenantId,
      name: claims.name ?? 'Jane Doe',
      preferred_username: claims.preferred_username ?? 'jane.doe@apf.example',
      amr: claims.amr ?? ['pwd', 'mfa'],
    },
    account: { username: 'jane.doe@apf.example', name: 'Jane Doe' },
  } as unknown as AuthenticationResult;
}

const PRE_AUTH_OK: PreAuthPayload = {
  state: 'state-nonce',
  codeVerifier: 'verifier-secret',
  createdAt: 1_000_000,
};

describe('AuthService.beginAuthCodeFlow', () => {
  it('builds the auth URL with the configured redirect, OIDC scopes, S256 challenge', async () => {
    const { service, getAuthCodeUrl } = makeService();
    await service.beginAuthCodeFlow();
    expect(getAuthCodeUrl).toHaveBeenCalledTimes(1);
    const arg = getAuthCodeUrl.mock.calls[0]?.[0] as Record<string, unknown>;
    expect(arg['redirectUri']).toBe(ENTRA.redirectUri);
    expect(arg['scopes']).toEqual(['openid', 'profile', 'email']);
    expect(arg['codeChallengeMethod']).toBe('S256');
    expect(typeof arg['codeChallenge']).toBe('string');
    expect(typeof arg['state']).toBe('string');
  });

  it('returns the pre-auth payload with state + codeVerifier matching what MSAL was called with', async () => {
    const { service, getAuthCodeUrl } = makeService();
    const { preAuthPayload } = await service.beginAuthCodeFlow();
    const arg = getAuthCodeUrl.mock.calls[0]?.[0] as Record<string, unknown>;
    expect(preAuthPayload.state).toBe(arg['state']);
    expect(preAuthPayload.codeVerifier).not.toBe(arg['codeChallenge']);
    expect(preAuthPayload.createdAt).toBeLessThanOrEqual(Date.now());
  });

  it('generates a fresh state + verifier on every call', async () => {
    const { service } = makeService();
    const a = await service.beginAuthCodeFlow();
    const b = await service.beginAuthCodeFlow();
    expect(a.preAuthPayload.state).not.toBe(b.preAuthPayload.state);
    expect(a.preAuthPayload.codeVerifier).not.toBe(b.preAuthPayload.codeVerifier);
  });
});

describe('AuthService.completeAuthCodeFlow', () => {
  it('returns the authenticated user on the happy path', async () => {
    const { service, acquireTokenByCode } = makeService();
    const user = await service.completeAuthCodeFlow(
      'auth-code',
      PRE_AUTH_OK.state,
      PRE_AUTH_OK,
      PRE_AUTH_OK.createdAt + 1_000,
    );
    expect(acquireTokenByCode).toHaveBeenCalledWith({
      code: 'auth-code',
      codeVerifier: PRE_AUTH_OK.codeVerifier,
      redirectUri: ENTRA.redirectUri,
      scopes: ['openid', 'profile', 'email'],
    });
    expect(user).toEqual({
      oid: 'user-oid',
      tid: ENTRA.tenantId,
      username: 'jane.doe@apf.example',
      displayName: 'Jane Doe',
      amr: ['pwd', 'mfa'],
    });
  });

  it('throws state-mismatch when the query state differs from the cookie state', async () => {
    const { service } = makeService();
    await expect(
      service.completeAuthCodeFlow('code', 'other-state', PRE_AUTH_OK, PRE_AUTH_OK.createdAt),
    ).rejects.toMatchObject({ failure: { kind: 'state-mismatch' } });
  });

  it('throws flow-expired when the cookie is older than the TTL', async () => {
    const { service } = makeService();
    const now = PRE_AUTH_OK.createdAt + PRE_AUTH_COOKIE_TTL_MS + 1;
    await expect(
      service.completeAuthCodeFlow('code', PRE_AUTH_OK.state, PRE_AUTH_OK, now),
    ).rejects.toMatchObject({ failure: { kind: 'flow-expired' } });
  });

  it('throws amr-missing when the ID token has no amr claim', async () => {
    const acquireTokenByCode = jest.fn().mockResolvedValue(makeAuthResult({ amr: [] }));
    const { service } = makeService({ acquireTokenByCode });
    await expect(
      service.completeAuthCodeFlow('code', PRE_AUTH_OK.state, PRE_AUTH_OK, PRE_AUTH_OK.createdAt),
    ).rejects.toMatchObject({ failure: { kind: 'amr-missing' } });
  });

  it('throws token-exchange-failed when MSAL throws', async () => {
    const acquireTokenByCode = jest.fn().mockRejectedValue(new Error('AADSTS70008'));
    const { service } = makeService({ acquireTokenByCode });
    await expect(
      service.completeAuthCodeFlow('code', PRE_AUTH_OK.state, PRE_AUTH_OK, PRE_AUTH_OK.createdAt),
    ).rejects.toMatchObject({
      failure: { kind: 'token-exchange-failed', cause: 'AADSTS70008' },
    });
  });

  it('throws token-exchange-failed when MSAL returns null', async () => {
    const acquireTokenByCode = jest.fn().mockResolvedValue(null);
    const { service } = makeService({ acquireTokenByCode });
    await expect(
      service.completeAuthCodeFlow('code', PRE_AUTH_OK.state, PRE_AUTH_OK, PRE_AUTH_OK.createdAt),
    ).rejects.toBeInstanceOf(AuthCodeFlowException);
  });

  it('throws token-exchange-failed when oid claim is missing', async () => {
    const acquireTokenByCode = jest.fn().mockResolvedValue({
      idTokenClaims: { tid: ENTRA.tenantId, amr: ['mfa'] },
      account: { username: '', name: '' },
    } as unknown as AuthenticationResult);
    const { service } = makeService({ acquireTokenByCode });
    await expect(
      service.completeAuthCodeFlow('code', PRE_AUTH_OK.state, PRE_AUTH_OK, PRE_AUTH_OK.createdAt),
    ).rejects.toMatchObject({
      failure: { kind: 'token-exchange-failed', cause: /oid/ },
    });
  });
});