s3-backed-object

S3-backed-object is a small wrapper that takes bucket and key in constructor and provides set and get methods for accessing the encapsulated object. The object is cached in memory from last set or get call, but on every get a call to S3 is made to ensure that the version in memory is the latest.

Usage

This module makes use of async/await and requires Node 8 at minimum to run.

Both get and set return a Promise. Any errors (except 404 when getting, and 304 when not modified) from S3 are forwarded as-is.

Basic usage:

S3Object = require('s3-backed-object')
const obj = new S3Object({bucket: 'bucket', key: 'key'}, {region: 'eu-west-1'})
await obj.set({hello: 'world'})
// The object is now stored as s3://bucket/key and obj instance remembers
// the ETag returned by s3.putObject.
await obj.get()
// The above will resolve into {hello: 'world'} after checking with s3.getObject
// and the remembered ETag for changes (and getting 304 not modified).

The constructor parameters are S3Object({bucket, key}, s3opts), where:

• bucket and key specify the object
• s3opts specify any additional options for AWS.S3 constructor such as region or access keys.