Pruebas de email con Cypress: registro, OTP y reset

import { defineConfig } from 'cypress';

const API = 'https://grabmail.io/api/v1';
const sleep = (ms: number) => new Promise(r => setTimeout(r, ms));

type Args = { address: string; subjectContains?: string; fromContains?: string; timeoutMs?: number };

export default defineConfig({
  e2e: {
    baseUrl: 'http://localhost:3000',
    taskTimeout: 90_000,                  // above the mail deadline below, always
    setupNodeEvents(on) {
      on('task', {
        /** Poll a mailbox until a matching message arrives, or the deadline passes. */
        async waitForMail({ address, subjectContains, fromContains, timeoutMs = 60_000 }: Args) {
          const deadline = Date.now() + timeoutMs;

          while (Date.now() < deadline) {
            const res = await fetch(`${API}/mailbox?address=${encodeURIComponent(address)}`);

            if (res.status === 429) {                  // slow down, do not fail
              await sleep(Number(res.headers.get('retry-after') ?? 1) * 1000);
              continue;
            }
            if (!res.ok) throw new Error(`GET /mailbox answered ${res.status} for ${address}`);

            const { messages } = (await res.json()) as { messages: { id: string; from: string; subject: string }[] };
            const hit = messages.find(m =>
              (!subjectContains || m.subject.toLowerCase().includes(subjectContains.toLowerCase())) &&
              (!fromContains    || m.from.toLowerCase().includes(fromContains.toLowerCase())));

            if (hit) {
              const full = await fetch(`${API}/message/${hit.id}?mailbox=${encodeURIComponent(address)}`);
              if (!full.ok) throw new Error(`GET /message answered ${full.status}`);
              return full.json();                      // the whole message, both parts
            }
            await sleep(1000);                         // one read a second, never throttled
          }
          return null;                                 // "not yet" is an answer, not an error
        },
      });
    },
  },
});

export type Message = {
  id: string; from: string; to: string; subject: string; date: string;
  text: string | null; html: string | null;
};
type WaitOpts = { subjectContains?: string; fromContains?: string; timeoutMs?: number };

declare global {
  namespace Cypress {
    interface Chainable {
      /** A mailbox nothing else in this run, or any previous run, is using. */
      freshAddress(prefix?: string): Chainable<string>;
      /** Block until a matching message arrives. Fails the test at the deadline. */
      waitForMail(address: string, opts?: WaitOpts): Chainable<Message>;
    }
  }
}

Cypress.Commands.add('freshAddress', (prefix = 'cy') =>
  cy.wrap(`${prefix}-${Math.random().toString(36).slice(2, 10)}@grabmail.io`, { log: false }));

Cypress.Commands.add('waitForMail', (address, opts = {}) =>
  cy.task<Message | null>('waitForMail', { address, ...opts }, { timeout: (opts.timeoutMs ?? 60_000) + 10_000 })
    .then(m => {
      expect(m, `a message for ${address}`).not.to.be.null;
      return cy.wrap(m as Message, { log: false });
    }));

/** The whole body, both parts, with the entities a link may carry undone. */
const bodyOf = (m: Message) => `${m.text ?? ''}\n${m.html ?? ''}`.replace(/&amp;/g, '&');

/** Anchored on your own wording, so a reworded template fails loudly. */
export function codeFrom(m: Message, pattern = /code is\s*([0-9]{6})/i): string {
  const hit = bodyOf(m).match(pattern);
  if (!hit) throw new Error(`no confirmation code in "${m.subject}"`);
  return hit[1];
}

/** The link whose path contains a fragment you know — never "the first URL". */
export function linkFrom(m: Message, pathContains: string): string {
  const hit = bodyOf(m).match(new RegExp(`https?://[^\\s"'<>]*${pathContains}[^\\s"'<>]*`));
  if (!hit) throw new Error(`no link containing "${pathContains}" in "${m.subject}"`);
  return hit[0];
}

import { codeFrom } from '../support/commands';

describe('sign-up', () => {
  it('confirms the address with the emailed code', () => {
    cy.freshAddress().then(address => {
      cy.visit('/signup');
      cy.get('input[name="email"]').type(address);
      cy.get('input[name="password"]').type('correct-horse-battery-staple');
      cy.contains('button', 'Create account').click();
      cy.contains('Check your inbox').should('be.visible');

      cy.waitForMail(address, { subjectContains: 'confirm' }).then(message => {
        cy.get('input[name="code"]').type(codeFrom(message));
        cy.contains('button', 'Confirm').click();
        cy.contains('h1', 'Welcome').should('be.visible');
      });
    });
  });
});

import { codeFrom } from '../support/commands';

describe('login with an emailed one-time code', () => {
  it('asks for the code and accepts it', () => {
    cy.freshAddress().then(address => {
      // Your application's own test seam: an internal endpoint, a DB fixture, a CLI.
      cy.request('POST', '/internal/test/users', { email: address, password: 'hunter2hunter2', otpByEmail: true });

      cy.visit('/login');
      cy.get('input[name="email"]').type(address);
      cy.get('input[name="password"]').type('hunter2hunter2');
      cy.contains('button', 'Log in').click();
      cy.contains('Enter the code we emailed you').should('be.visible');

      cy.waitForMail(address, { subjectContains: 'code' }).then(message => {
        cy.get('input[name="otp"]').type(codeFrom(message, /code is\s*([0-9]{6})/i));
        cy.contains('button', 'Continue').click();
        cy.url().should('include', '/dashboard');
      });
    });
  });
});

import { linkFrom } from '../support/commands';

describe('password reset', () => {
  it('changes the password through the emailed link', () => {
    cy.freshAddress().then(address => {
      cy.request('POST', '/internal/test/users', { email: address, password: 'old-password-1' });

      cy.visit('/forgot-password');
      cy.get('input[name="email"]').type(address);
      cy.contains('button', 'Send reset link').click();

      cy.waitForMail(address, { subjectContains: 'reset' }).then(message => {
        cy.visit(linkFrom(message, '/reset/'));      // same origin as baseUrl: a plain visit
        cy.get('input[name="password"]').type('new-password-2');
        cy.contains('button', 'Change password').click();
      });

      cy.visit('/login');
      cy.get('input[name="email"]').type(address);
      cy.get('input[name="password"]').type('new-password-2');
      cy.contains('button', 'Log in').click();
      cy.url().should('include', '/dashboard');
    });
  });
});