Handle Timeouts

When a lambda times out it throws an error that cannot be caught by middy. To work around this middy maintains an AbortController that can be signalled early to allow time to clean up and log the error properly.

You can set timeoutEarlyInMillis to 0 to disable this functionality. If you want to override during testing, mock the lambda context to set getRemainingTimeInMillis to a function that returns a very large value (e.g. () => 99999).

import middy from '@middy/core'

const lambdaHandler = (event, context, {signal}) => {
  signal.onabort = () => {
    // cancel events
  }
  // ... 
}

export const handler = middy(lambdaHandler, {
  timeoutEarlyInMillis: 50,
  timeoutEarlyResponse: () => {
    return {
      statusCode: 408
    }
  }
})