HowTo: Implement user sign up and login with AWS Cognito

signUp.js

async function signUp(email, password) {
  try {
    const cognito = new AWS.CognitoIdentityServiceProvider()
    await cognito.adminCreateUser({
      UserPoolId: process.env.USER_POOL_ID,
      Username: email,
      MessageAction: 'SUPPRESS',
      TemporaryPassword: password,
    }).promise()

    const initAuthResponse = await cognito.adminInitiateAuth({
      AuthFlow: 'ADMIN_NO_SRP_AUTH',
      ClientId: process.env.CLIENT_ID,
      UserPoolId: process.env.USER_POOL_ID,
      AuthParameters: {
        USERNAME: email,
        PASSWORD: password
      }
    }).promise()

    if (initAuthResponse.ChallengeName === 'NEW_PASSWORD_REQUIRED') {
      await cognito.adminRespondToAuthChallenge({
        ChallengeName: 'NEW_PASSWORD_REQUIRED',
        ClientId: process.env.CLIENT_ID,
        UserPoolId: process.env.USER_POOL_ID,
        ChallengeResponses: {
          USERNAME: email,
          NEW_PASSWORD: password,
        },
        Session: initAuthResponse.Session
      }).promise()
    }
  } catch (err) {
    throw err
  }
}