s3 interface to facilitate testing

[hra...@0brg.net]

Hi goamz users (this makes it sound like im addressing a support group for some exotic psychedelic drug)

how do you organize your unit tests and general system tests? a while ago i was working on a system which used s3 but the problem was id have to connect to amazon every time i was testing the service which was cumbersome

so instead of using the s3.S3 type in my code i created a proxy interface that wraps it:

https://github.com/hraban/s3iface

basically it serves as a drop in:

import (

goamzs3 "launchpad.net/goamz/s3"

s3 "github.com/hraban/s3iface"

)

then there are two ways to satisfy the S3 interface:

- real S3  s3.WrapS3(goamzs3.New(auth, aws.EUWest))

see https://github.com/hraban/s3iface/blob/master/backend_s3_test.go

- or the FS  s3.WrapFS("/tmp/foo")

see https://github.com/hraban/s3iface/blob/master/backend_fs_test.go

you could influence that with a build flag or command line arg

the filesystem wrapper is not perfect but it suited my needs more or less

anyway this all got me thinking am I the only one to want / do something like this or how do other people solve it?

it would be nice if goamz itself made S3 an interface and not a struct with methods that would make creating custom implementations that satisfy the interface ("s3 simulators") much nicer.

by much nicer i mean i wouldnt have to do the drop-in import trick in every file that uses s3 i could just pass my custom implementation as long as it satisfies the official s3 interface.

stay cool

hraban