s3.getObject().createReadStream() : How to catch the error?

Question

I am trying to write a program to get a zip file from s3, unzip it, then upload it to S3. But I found two exceptions that I can not catch.

1.

Answer 1

If you'd like to catch the NoSuchKey error thrown by createReadStream you have 2 options:

1. Check if key exists before reading it.
2. Catch error from stream

First:

s3.getObjectMetadata(key)
  .promise()
  .then(() => {
    // This will not throw error anymore
    s3.getObject().createReadStream();
  })
  .catch(error => {
    if (error.statusCode === 404) {
      // Catching NoSuchKey
    }
  });

The only case when you won't catch error if file was deleted in a split second, between parsing response from getObjectMetadata and running createReadStream

Second:

s3.getObject().createReadStream().on('error', error => {
    // Catching NoSuchKey & StreamContentLengthMismatch
});

This is a more generic approach and will catch all other errors, like network problems.