Cypress extension for logging in with amplify-js auth

cypress-amplify-js.ts

/**
 * amplify-js / cognito auth helper
 * specific personas are logged-in and their tokens are cached to save on round-trips.
 */
import { Amplify } from 'aws-amplify';
import { signIn, SignInOutput, signOut } from '@aws-amplify/auth';
import { ResourcesConfig } from '@aws-amplify/core';

console.log('configuring amplify');

// configure amplify
const auth = Cypress.env().auth;
const cognitoConfig: ResourcesConfig = {
  Auth: {
    Cognito: {
      userPoolId: auth.userPoolId,
      userPoolClientId: auth.userPoolClientId
    }
  }
};

Amplify.configure(cognitoConfig);

type StorageValue = string | null;
type StorageMap = Map<string, StorageValue>;

const exportStorage = (): StorageMap => {
  const keyValueStore = new Map<string, StorageValue>(); // storageMap();

  for (let i = 0, l = localStorage.length; i < l; i++) {
    const key = localStorage.key(i) as string;
    keyValueStore.set(key, localStorage.getItem(key));
  }
  return keyValueStore;
};

const importStorage = (storage: StorageMap, clearBefore: boolean) => {
  if (clearBefore) {
    localStorage.clear();
  }

  storage.forEach((value: StorageValue, key: string) => {
    localStorage.setItem(key, value as string);
  });
};

const cognitoUserCache = new Map<string, StorageMap>(); // userCache();

Cypress.Commands.add('signInAs', (persona) => {
  const userStorage = cognitoUserCache.get(persona.username);
  if (userStorage) {
    console.log('recycling user', persona.username);
    importStorage(userStorage, true);
    return;
  }

  console.log('signing in', persona.username);

  return signIn({
    username: persona.username,
    password: persona.password,
    options: {
      authFlowType: 'CUSTOM_WITH_SRP'
    }
  })
    .then((output: SignInOutput) => {
      cognitoUserCache.set(persona.username, exportStorage());
      if (!output.isSignedIn) throw new Error('User could not be signed in');
    })
    .catch((err: any) => {
      console.error(err);
    });
});

Cypress.Commands.add('signOut', () => {
  console.log('signing out');
  return signOut();
});